Fidelity SAI Municipal Income NCSR Certified annual shareholder report (management investment company)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED

MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number 811-2105

Fidelity Salem Street Trust

(Exact name of registrant as specified in charter)

245 Summer St., Boston, Massachusetts 02210

(Address of principal executive offices) (Zip code)

William C. Coffey, Secretary

245 Summer St.

Boston, Massachusetts 02210

(Name and address of agent for service)

Registrant's telephone number, including area code:

617-563-7000


Date of fiscal year end:	February 28

Date of reporting period:	February 28, 2019

Item 1.

Reports to Stockholders

Fidelity® SAI Long-Term Treasury Bond Index Fund

Offered exclusively to certain clients of the Adviser or its affiliates - not available for sale to the general public. Fidelity SAI is a product name of Fidelity^® funds dedicated to certain programs affiliated with Strategic Advisers LLC.

Annual Report

February 28, 2019

Beginning on January 1, 2021, as permitted by regulations adopted by the Securities and Exchange Commission, paper copies of a fund’s shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the fund or from your financial intermediary, such as a financial advisor, broker-dealer or bank. Instead, the reports will be made available on a website, and you will be notified by mail each time a report is posted and provided with a website link to access the report.

If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from a fund electronically, by contacting your financial intermediary. For Fidelity customers, visit Fidelity's web site or call Fidelity using the contact information listed below.

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Account Type	Website	Phone Number
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Contents

Performance
Management's Discussion of Fund Performance
Investment Summary
Schedule of Investments
Financial Statements
Notes to Financial Statements
Report of Independent Registered Public Accounting Firm
Trustees and Officers
Shareholder Expense Example
Distributions
Board Approval of Investment Advisory Contracts and Management Fees

To view a fund's proxy voting guidelines and proxy voting record for the 12-month period ended June 30, visit http://www.fidelity.com/proxyvotingresults or visit the Securities and Exchange Commission's (SEC) web site at http://www.sec.gov.

You may also call 1-800-544-3455 to request a free copy of the proxy voting guidelines.

Standard & Poor's, S&P and S&P 500 are registered service marks of The McGraw-Hill Companies, Inc. and have been licensed for use by Fidelity Distributors Corporation.

Other third-party marks appearing herein are the property of their respective owners.

This report and the financial statements contained herein are submitted for the general information of the shareholders of the Fund. This report is not authorized for distribution to prospective investors in the Fund unless preceded or accompanied by an effective prospectus.

A fund files its complete schedule of portfolio holdings with the SEC for the first and third quarters of each fiscal year on Form N-Q. Forms N-Q are available on the SEC’s web site at http://www.sec.gov. A fund's Forms N-Q may be reviewed and copied at the SEC’s Public Reference Room in Washington, DC. Information regarding the operation of the SEC's Public Reference Room may be obtained by calling 1-800-SEC-0330.

For a complete list of a fund's portfolio holdings, view the most recent holdings listing, semiannual report, or annual report on Fidelity's web site at http://www.fidelity.com, http://www.institutional.fidelity.com, or http://www.401k.com, as applicable.

NOT FDIC INSURED •MAY LOSE VALUE •NO BANK GUARANTEE

Neither the Fund nor Fidelity Distributors Corporation is a bank.

Performance: The Bottom Line

Average annual total return reflects the change in the value of an investment, assuming reinvestment of distributions from dividend income and capital gains (the profits earned upon the sale of securities that have grown in value, if any) and assuming a constant rate of performance each year. The hypothetical investment and the average annual total returns do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. During periods of reimbursement by Fidelity, a fund’s total return will be greater than it would be had the reimbursement not occurred. How a fund did yesterday is no guarantee of how it will do tomorrow.

Average Annual Total Returns

For the periods ended February 28, 2019	Past 1 year	Life of fund^A
Fidelity® SAI Long-Term Treasury Bond Index Fund	4.38%	2.11%

^A From October 8, 2015

$10,000 Over Life of Fund

Let's say hypothetically that $10,000 was invested in Fidelity® SAI Long-Term Treasury Bond Index Fund on October 8, 2015, when the fund started.

The chart shows how the value of your investment would have changed, and also shows how the Bloomberg Barclays U.S. 20+ Year Treasury Bond Index performed over the same period.

	Period Ending Values
	$10,734	Fidelity® SAI Long-Term Treasury Bond Index Fund
	$10,727	Bloomberg Barclays U.S. 20+ Year Treasury Bond Index

Management's Discussion of Fund Performance

Market Recap: U.S. taxable investment-grade bonds rose for the 12 months ending February 28, 2019, as the fairly calm market early in the period turned volatile before settling down in late 2018 and early in the new year. The Bloomberg Barclays U.S. Aggregate Bond Index gained 3.17%. Longer-term bond yields advanced through mid-May, driven by policy-rate hikes and plans by the U.S. Federal Reserve to reduce its balance sheet. Yields moderated in the summer, with spreads between shorter-term and longer-term Treasury bonds remaining tight, partly because of escalating global trade tension, before rising a bit in September and early October on expectations for higher inflation. Yields then declined and credit spreads widened in November and December due to broad market volatility, disappointing U.S. manufacturing data and signs of a global slowdown. Yield spreads narrowed in January and to a lesser degree in February, partly because the U.S. Federal Reserve signaled that it would be “patient” with future interest rate hikes. Within the Bloomberg Barclays index, the securitized segment posted the heftiest gain (+3.60%), followed by U.S. Treasuries (+3.23%) and corporate bonds (+2.63%). Outside the index, most non-core fixed-income segments moderately topped nominal U.S. Treasuries, and Treasury Inflation-Protected Securities (TIPS) returned 1.91%.

Comments from Co-Portfolio Managers Brandon Bettencourt and Jay Small: For the fiscal year, the fund gained 4.38%, net of fees, outpacing the 3.94% advance of the benchmark Bloomberg Barclays 20+ Year Treasury Bond Index. The bulk of the fund’s outperformance was incurred in June 2018 when we sold a number of holdings at advantageous prices to meet shareholder outflows. In managing the fund, our goal is to produce monthly returns, before expenses, that closely match the benchmark’s returns. We use a method known as stratified sampling, which matches the index’s risk factors, but does not always hold all bonds in the exact proportions of the index. From March through November 2018, U.S. Treasuries were under pressure due to rising interest rates and expectations for further policy rate increases by the Federal Reserve. Another factor weighing on U.S. Treasuries was the Fed’s decision to begin reducing the $4.5 trillion in government securities it accumulated as part of the quantitative easing program it deployed to battle the recession and financial crisis a decade ago. That said, from December through period end, U.S. Treasury prices rallied strongly after the Fed made a dovish pivot, indicating that the case for raising interest rates had weakened somewhat with slowing global economic growth and muted inflation. Moreover, the Fed communicated that it would be patient in assessing the need for further interest rate hikes. Against this backdrop, the yield curve flattened and both intermediate- and long-term U.S. Treasuries outperformed their shorter-term counterparts.

The views expressed above reflect those of the portfolio manager(s) only through the end of the period as stated on the cover of this report and do not necessarily represent the views of Fidelity or any other person in the Fidelity organization. Any such views are subject to change at any time based upon market or other conditions and Fidelity disclaims any responsibility to update such views. These views may not be relied on as investment advice and, because investment decisions for a Fidelity fund are based on numerous factors, may not be relied on as an indication of trading intent on behalf of any Fidelity fund.

Investment Summary (Unaudited)

Coupon Distribution as of February 28, 2019

	% of fund's investments
2 - 2.99%	29.7
3 - 3.99%	57.2
4 - 4.99%	12.3

Coupon distribution shows the range of stated interest rates on the fund's investments, excluding short-term investments.

Asset Allocation (% of fund's net assets)

As of February 28, 2019
	U.S. Treasury Obligations	99.7%
	Short-Term Investments and Net Other Assets (Liabilities)	0.3%

Schedule of Investments February 28, 2019

Showing Percentage of Net Assets

U.S. Government and Government Agency Obligations - 99.7%
	Principal Amount	Value
U.S. Treasury Obligations - 99.7%
U.S. Treasury Bonds:
2.25% 8/15/46	$1,852,000	$1,563,421
2.5% 2/15/45	1,911,700	1,711,196
2.5% 2/15/46	1,828,000	1,630,062
2.5% 5/15/46	1,819,000	1,620,828
2.75% 8/15/42	1,107,500	1,049,226
2.75% 11/15/42	1,335,100	1,263,234
2.75% 8/15/47	1,857,000	1,737,238
2.75% 11/15/47	1,841,000	1,720,975
2.875% 5/15/43	2,041,200	1,970,476
2.875% 8/15/45	2,029,100	1,952,850
2.875% 11/15/46	1,811,000	1,740,753
3% 5/15/42	814,700	806,935
3% 11/15/44	1,948,800	1,920,482
3% 5/15/45	1,942,800	1,915,252
3% 11/15/45	1,926,000	1,898,163
3% 2/15/47	1,869,000	1,841,914
3% 5/15/47	1,848,000	1,818,836
3% 2/15/48	1,954,000	1,919,958
3% 8/15/48	2,219,000	2,180,774
3% 2/15/49	971,000	954,842
3.125% 11/15/41	703,700	713,321
3.125% 2/15/42	883,100	894,346
3.125% 2/15/43	1,338,600	1,351,149
3.125% 8/15/44	1,929,300	1,943,920
3.125% 5/15/48	2,090,000	2,104,450
3.375% 5/15/44	1,969,800	2,071,676
3.375% 11/15/48	2,383,000	2,519,280
3.625% 8/15/43	1,689,600	1,849,980
3.625% 2/15/44	1,923,500	2,107,284
3.75% 8/15/41	752,700	840,672
3.75% 11/15/43	1,938,100	2,164,918
3.875% 8/15/40	723,700	823,774
4.25% 5/15/39	556,100	666,473
4.25% 11/15/40	826,800	990,416
4.375% 11/15/39	622,200	757,601
4.375% 5/15/40	862,700	1,050,539
4.375% 5/15/41	664,700	810,596
4.5% 8/15/39	561,000	694,303
4.625% 2/15/40	1,059,900	1,332,907
4.75% 2/15/41	887,900	1,136,547
		60,041,567
TOTAL U.S. GOVERNMENT AND GOVERNMENT AGENCY OBLIGATIONS
(Cost $59,579,272)		60,041,567
	Shares	Value

Money Market Funds - 0.8%
Fidelity Cash Central Fund, 2.44% (a)
(Cost $474,298)	474,223	474,318
TOTAL INVESTMENT IN SECURITIES - 100.5%
(Cost $60,053,570)		60,515,885
NET OTHER ASSETS (LIABILITIES) - (0.5)%		(278,059)
NET ASSETS - 100%		$60,237,826

Legend

(a) Affiliated fund that is generally available only to investment companies and other accounts managed by Fidelity Investments. The rate quoted is the annualized seven-day yield of the fund at period end. A complete unaudited listing of the fund's holdings as of its most recent quarter end is available upon request. In addition, each Fidelity Central Fund's financial statements, which are not covered by the Fund's Report of Independent Registered Public Accounting Firm, are available on the SEC's website or upon request.

Affiliated Central Funds

Information regarding fiscal year to date income earned by the Fund from investments in Fidelity Central Funds is as follows:

Fund	Income earned
Fidelity Cash Central Fund	$5,419
Total	$5,419

Amounts in the income column in the above table include any capital gain distributions from underlying funds, which are presented in the corresponding line-item in the Statement of Operations, if applicable.

Investment Valuation

The following is a summary of the inputs used, as of February 28, 2019, involving the Fund's assets and liabilities carried at fair value. The inputs or methodology used for valuing securities may not be an indication of the risk associated with investing in those securities. For more information on valuation inputs, and their aggregation into the levels used below, please refer to the Investment Valuation section in the accompanying Notes to Financial Statements.

	Valuation Inputs at Reporting Date:
Description	Total	Level 1	Level 2	Level 3
Investments in Securities:
U.S. Government and Government Agency Obligations	$60,041,567	$--	$60,041,567	$--
Money Market Funds	474,318	474,318	--	--
Total Investments in Securities:	$60,515,885	$474,318	$60,041,567	$--

See accompanying notes which are an integral part of the financial statements.

Financial Statements

Statement of Assets and Liabilities

		February 28, 2019
Assets
Investment in securities, at value — See accompanying schedule: Unaffiliated issuers (cost $59,579,272)	$60,041,567
Fidelity Central Funds (cost $474,298)	474,318
Total Investment in Securities (cost $60,053,570)		$60,515,885
Cash		18,482
Receivable for investments sold		683,816
Receivable for fund shares sold		187,534
Interest receivable		313,379
Distributions receivable from Fidelity Central Funds		471
Prepaid expenses		166
Receivable from investment adviser for expense reductions		12,119
Total assets		61,731,852
Liabilities
Payable for investments purchased	$1,279,509
Payable for fund shares redeemed	29,434
Distributions payable	130,756
Accrued management fee	1,980
Other affiliated payables	4,995
Other payables and accrued expenses	47,352
Total liabilities		1,494,026
Net Assets		$60,237,826
Net Assets consist of:
Paid in capital		$89,789,095
Total distributable earnings (loss)		(29,551,269)
Net Assets, for 6,195,718 shares outstanding		$60,237,826
Net Asset Value, offering price and redemption price per share ($60,237,826 ÷ 6,195,718 shares)		$9.72

See accompanying notes which are an integral part of the financial statements.

Statement of Operations

		Year ended February 28, 2019
Investment Income
Interest		$5,890,056
Income from Fidelity Central Funds		5,419
Total income		5,895,475
Expenses
Management fee	$77,400
Transfer agent fees	145,124
Accounting fees and expenses	47,426
Custodian fees and expenses	2,973
Independent trustees' fees and expenses	1,238
Registration fees	64,583
Audit	57,569
Legal	374
Miscellaneous	2,723
Total expenses before reductions	399,410
Expense reductions	(338,820)
Total expenses after reductions		60,590
Net investment income (loss)		5,834,885
Realized and Unrealized Gain (Loss)
Net realized gain (loss) on:
Investment securities:
Unaffiliated issuers	(23,933,406)
Fidelity Central Funds	(19)
Total net realized gain (loss)		(23,933,425)
Change in net unrealized appreciation (depreciation) on:
Investment securities:
Unaffiliated issuers	35,008,762
Fidelity Central Funds	20
Total change in net unrealized appreciation (depreciation)		35,008,782
Net gain (loss)		11,075,357
Net increase (decrease) in net assets resulting from operations		$16,910,242

See accompanying notes which are an integral part of the financial statements.

Statement of Changes in Net Assets

	Year ended February 28, 2019	Year ended February 28, 2018
Increase (Decrease) in Net Assets
Operations
Net investment income (loss)	$5,834,885	$18,161,160
Net realized gain (loss)	(23,933,425)	(1,605,750)
Change in net unrealized appreciation (depreciation)	35,008,782	(19,384,514)
Net increase (decrease) in net assets resulting from operations	16,910,242	(2,829,104)
Distributions to shareholders	(5,726,671)	–
Distributions to shareholders from net investment income	–	(18,052,244)
Total distributions	(5,726,671)	(18,052,244)
Share transactions
Proceeds from sales of shares	133,735,649	994,733,351
Reinvestment of distributions	33,388	7,163,349
Cost of shares redeemed	(910,162,012)	(920,281,066)
Net increase (decrease) in net assets resulting from share transactions	(776,392,975)	81,615,634
Total increase (decrease) in net assets	(765,209,404)	60,734,286
Net Assets
Beginning of period	825,447,230	764,712,944
End of period	$60,237,826	$825,447,230
Other Information
Undistributed net investment income end of period		$119,433
Shares
Sold	13,876,679	98,917,854
Issued in reinvestment of distributions	3,450	717,067
Redeemed	(93,729,190)	(91,145,326)
Net increase (decrease)	(79,849,061)	8,489,595

See accompanying notes which are an integral part of the financial statements.

Financial Highlights

Fidelity SAI Long-Term Treasury Bond Index Fund


Years ended February 28,	2019	2018	2017	2016 ^A
Selected Per–Share Data
Net asset value, beginning of period	$9.59	$9.86	$10.69	$10.00
Income from Investment Operations
Net investment income (loss)^B	.292	.278	.271	.107
Net realized and unrealized gain (loss)	.123	(.272)	(.767)	.689
Total from investment operations	.415	.006	(.496)	.796
Distributions from net investment income	(.285)	(.276)	(.268)	(.106)
Distributions from net realized gain	–	–	(.066)	–
Total distributions	(.285)	(.276)	(.334)	(.106)
Net asset value, end of period	$9.72	$9.59	$9.86	$10.69
Total Return^C,^D	4.38%	(.03)%	(4.77)%	8.02%
Ratios to Average Net Assets^E,^F
Expenses before reductions	.20%	.18%	.16%	.20%^G
Expenses net of fee waivers, if any	.03%	.06%	.11%	.15%^G
Expenses net of all reductions	.03%	.06%	.11%	.15%^G
Net investment income (loss)	2.99%	2.77%	2.57%	2.65%^G
Supplemental Data
Net assets, end of period (000 omitted)	$60,238	$825,447	$764,713	$728,409
Portfolio turnover rate^H	57%	128%	25%	18%^I

^A For the period October 8, 2015 (commencement of operations) to February 29, 2016.

^B Calculated based on average shares outstanding during the period.

^C Total returns for periods of less than one year are not annualized.

^D Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

^E Fees and expenses of any underlying Fidelity Central Funds are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of the expenses of any underlying Fidelity Central Funds.

^F Expense ratios reflect operating expenses of the Fund. Expenses before reductions do not reflect amounts reimbursed by the investment adviser or reductions from expense offset arrangements and do not represent the amount paid by the Fund during periods when reimbursements or reductions occur. Expense ratios before reductions for start-up periods may not be representative of longer term operating periods. Expenses net of fee waivers reflect expenses after reimbursement by the investment adviser but prior to reductions from expense offset arrangements. Expenses net of all reductions represent the net expenses paid by the Fund.

^G Annualized

^H Amount does not include the portfolio activity of any underlying Fidelity Central Funds.

^I Amount not annualized.

See accompanying notes which are an integral part of the financial statements.

Notes to Financial Statements

For the period ended February 28, 2019

1. Organization.

Fidelity SAI Long-Term Treasury Bond Index Fund (the Fund) is a fund of Fidelity Salem Street Trust (the Trust) and is authorized to issue an unlimited number of shares. Shares are offered exclusively to certain clients of Fidelity Management & Research Company (FMR) or its affiliates. The Trust is registered under the Investment Company Act of 1940, as amended (the 1940 Act), as an open-end management investment company organized as a Massachusetts business trust.

2. Investments in Fidelity Central Funds.

The Fund invests in Fidelity Central Funds, which are open-end investment companies generally available only to other investment companies and accounts managed by the investment adviser and its affiliates. The Fund's Schedule of Investments lists each of the Fidelity Central Funds held as of period end, if any, as an investment of the Fund, but does not include the underlying holdings of each Fidelity Central Fund. As an Investing Fund, the Fund indirectly bears its proportionate share of the expenses of the underlying Fidelity Central Funds.

The Money Market Central Funds seek preservation of capital and current income and are managed by Fidelity Investments Money Management, Inc. (FIMM), an affiliate of the investment adviser. Annualized expenses of the Money Market Central Funds as of their most recent shareholder report date are less than .005%.

A complete unaudited list of holdings for each Fidelity Central Fund is available upon request or at the Securities and Exchange Commission (the SEC) website at www.sec.gov. In addition, the financial statements of the Fidelity Central Funds, which are not covered by the Fund's Report of Independent Registered Public Accounting Firm, are available on the SEC website or upon request.

3. Significant Accounting Policies.

The Fund is an investment company and applies the accounting and reporting guidance of the Financial Accounting Standards Board (FASB) Accounting Standards Codification Topic 946 Financial Services – Investments Companies. The financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP), which require management to make certain estimates and assumptions at the date of the financial statements. Actual results could differ from those estimates. Subsequent events, if any, through the date that the financial statements were issued have been evaluated in the preparation of the financial statements. The following summarizes the significant accounting policies of the Fund:

Investment Valuation. Investments are valued as of 4:00 p.m. Eastern time on the last calendar day of the period. The Board of Trustees (the Board) has delegated the day to day responsibility for the valuation of the Fund's investments to the Fair Value Committee (the Committee) established by the Fund's investment adviser. In accordance with valuation policies and procedures approved by the Board, the Fund attempts to obtain prices from one or more third party pricing vendors or brokers to value its investments. When current market prices, quotations or currency exchange rates are not readily available or reliable, investments will be fair valued in good faith by the Committee, in accordance with procedures adopted by the Board. Factors used in determining fair value vary by investment type and may include market or investment specific events, changes in interest rates and credit quality. The frequency with which these procedures are used cannot be predicted and they may be utilized to a significant extent. The Committee oversees the Fund's valuation policies and procedures and reports to the Board on the Committee's activities and fair value determinations. The Board monitors the appropriateness of the procedures used in valuing the Fund's investments and ratifies the fair value determinations of the Committee.

The Fund categorizes the inputs to valuation techniques used to value its investments into a disclosure hierarchy consisting of three levels as shown below:

Level 1 – quoted prices in active markets for identical investments
Level 2 – other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, etc.)
Level 3 – unobservable inputs (including the Fund's own assumptions based on the best information available)

Valuation techniques used to value the Fund's investments by major category are as follows:

Debt securities, including restricted securities, are valued based on evaluated prices received from third party pricing vendors or from brokers who make markets in such securities. U.S. government and government agency obligations are valued by pricing vendors who utilize matrix pricing which considers yield or price of bonds of comparable quality, coupon, maturity and type or by broker-supplied prices. When independent prices are unavailable or unreliable, debt securities may be valued utilizing pricing methodologies which consider similar factors that would be used by third party pricing vendors. Debt securities are generally categorized as Level 2 in the hierarchy but may be Level 3 depending on the circumstances.

Investments in open-end mutual funds, including the Fidelity Central Funds, are valued at their closing net asset value (NAV) each business day and are categorized as Level 1 in the hierarchy.

Changes in valuation techniques may result in transfers in or out of an assigned level within the disclosure hierarchy. The aggregate value of investments by input level as of February 28, 2019 is included at the end of the Fund's Schedule of Investments.

Investment Transactions and Income. For financial reporting purposes, the Fund's investment holdings and NAV include trades executed through the end of the last business day of the period. The NAV per share for processing shareholder transactions is calculated as of the close of business of the New York Stock Exchange (NYSE), normally 4:00 p.m. Eastern time and includes trades executed through the end of the prior business day. Gains and losses on securities sold are determined on the basis of identified cost. Income and capital gain distributions from Fidelity Central Funds, if any, are recorded on the ex-dividend date. Interest income is accrued as earned and includes coupon interest and amortization of premium and accretion of discount on debt securities as applicable.

Expenses. Expenses directly attributable to a fund are charged to that fund. Expenses attributable to more than one fund are allocated among the respective funds on the basis of relative net assets or other appropriate methods. Expense estimates are accrued in the period to which they relate and adjustments are made when actual amounts are known.

Income Tax Information and Distributions to Shareholders. Each year, the Fund intends to qualify as a regulated investment company under Subchapter M of the Internal Revenue Code, including distributing substantially all of its taxable income and realized gains. As a result, no provision for U.S. Federal income taxes is required. As of February 28, 2019, the Fund did not have any unrecognized tax benefits in the financial statements; nor is the Fund aware of any tax positions for which it is reasonably possible that the total amounts of unrecognized tax benefits will significantly change in the next twelve months. The Fund files a U.S. federal tax return, in addition to state and local tax returns as required. The Fund's federal income tax returns are subject to examination by the Internal Revenue Service (IRS) for a period of three fiscal years after they are filed. State and local tax returns may be subject to examination for an additional fiscal year depending on the jurisdiction.

Distributions are declared and recorded daily and paid monthly from net investment income. Distributions from realized gains, if any, are declared and recorded on the ex-dividend date. Income and capital gain distributions are determined in accordance with income tax regulations, which may differ from GAAP.

Capital accounts within the financial statements are adjusted for permanent book-tax differences. These adjustments have no impact on net assets or the results of operations. Capital accounts are not adjusted for temporary book-tax differences which will reverse in a subsequent period.

Book-tax differences are primarily due to market discount, capital loss carryforwards and losses deferred due to wash sales and excise tax regulations.

As of period end, the cost and unrealized appreciation (depreciation) in securities, and derivatives if applicable, for federal income tax purposes were as follows:

Gross unrealized appreciation	$448,182
Gross unrealized depreciation	(740,803)
Net unrealized appreciation (depreciation)	$(292,621)
Tax Cost	$60,808,506

The tax-based components of distributable earnings as of period end were as follows:

Capital loss carryforward	$(29,141,331)
Net unrealized appreciation (depreciation) on securities and other investments	$(292,621)

Capital loss carryforwards are only available to offset future capital gains of the Fund to the extent provided by regulations and may be limited. Under the Regulated Investment Company Modernization Act of 2010 (the Act), the Fund is permitted to carry forward capital losses incurred in taxable years beginning after December 22, 2010 for an unlimited period and such capital losses are required to be used prior to any losses that expire. The capital loss carryforward information presented below, including any applicable limitation, is estimated as of fiscal period end and is subject to adjustment.

No expiration
Short-term	$(19,069,656)
Long-term	(10,071,675)
Total no expiration	$(29,141,331)
Total capital loss carryforward	$(29,141,331)

The tax character of distributions paid was as follows:

	February 28, 2019	February 28, 2018
Ordinary Income	$5,726,671	$ 18,052,244

New Rule Issuance. During August 2018, the U.S. Securities and Exchange Commission issued Final Rule Release No. 33-10532, Disclosure Update and Simplification. This Final Rule includes amendments specific to registered investment companies that are intended to eliminate overlap in disclosure requirements between Regulation S-X and GAAP. In accordance with these amendments, certain line-items in the Fund's financial statements have been combined or removed for the current period as outlined in the table below.

Financial Statement	Current Line-Item Presentation (As Applicable)	Prior Line-Item Presentation (As Applicable)
Statement of Assets and Liabilities	Total distributable earnings (loss)	Undistributed/Distributions in excess of/Accumulated net investment income (loss) Accumulated/Undistributed net realized gain (loss) Net unrealized appreciation (depreciation)
Statement of Changes in Net Assets	N/A - removed	Undistributed/Distributions in excess of/Accumulated net investment income (loss) end of period
Statement of Changes in Net Assets	Distributions to shareholders	Distributions to shareholders from net investment income Distributions to shareholders from net realized gain

4. Fees and Other Transactions with Affiliates.

Transfer Agent Fees. Fidelity Investments Institutional Operations Company, Inc. (FIIOC), an affiliate of the investment adviser, is the Fund's transfer, dividend disbursing and shareholder servicing agent. FIIOC receives an asset-based fee of .075% of the Fund's average net assets. FIIOC pays for typesetting, printing and mailing of shareholder reports, except proxy statements.

Accounting Fees. Fidelity Service Company, Inc. (FSC), an affiliate of the investment adviser, maintains the Fund's accounting records. The fee is based on the level of average net assets for each month. For the period, the fees were equivalent to an annual rate of .02%.

5. Committed Line of Credit.

The Fund participates with other funds managed by the investment adviser or an affiliate in a $4.25 billion credit facility (the "line of credit") to be utilized for temporary or emergency purposes to fund shareholder redemptions or for other short-term liquidity purposes. The Fund has agreed to pay commitment fees on its pro-rata portion of the line of credit, which amounted to $942 and is reflected in Miscellaneous expenses on the Statement of Operations. During the period, the Fund did not borrow on this line of credit.

6. Expense Reductions.

The investment adviser contractually agreed to reimburse the Fund to the extent annual operating expenses exceeded .03% of average net assets. This reimbursement will remain in place through June 30, 2020. Some expenses, for example the compensation of the independent Trustees, and certain miscellaneous expenses such as proxy and shareholder meeting expenses, are excluded from this reimbursement. During the period this reimbursement reduced the Fund's expenses by $338,668.

In addition, through arrangements with the Fund's custodian, credits realized as a result of certain uninvested cash balances were used to reduce the Fund's expenses. During the period, these credits reduced the Fund's custody expenses by $152.

7. Other.

The Fund's organizational documents provide former and current trustees and officers with a limited indemnification against liabilities arising in connection with the performance of their duties to the Fund. In the normal course of business, the Fund may also enter into contracts that provide general indemnifications. The Fund's maximum exposure under these arrangements is unknown as this would be dependent on future claims that may be made against the Fund. The risk of material loss from such claims is considered remote.

Report of Independent Registered Public Accounting Firm

To the Trustees of Fidelity Salem Street Trust and Shareholders of Fidelity SAI Long-Term Treasury Bond Index Fund:

Opinion on the Financial Statements and Financial Highlights

We have audited the accompanying statement of assets and liabilities of Fidelity SAI Long-Term Treasury Bond Index Fund (the "Fund"), a fund of Fidelity Salem Street Trust, including the schedule of investments, as of February 28, 2019, the related statement of operations for the year then ended, the statement of changes in net assets for each of the two years in the period then ended, the financial highlights for each of the three years in the period then ended and for the period from October 8, 2015 (commencement of operations) to February 29, 2016, and the related notes. In our opinion, the financial statements and financial highlights present fairly, in all material respects, the financial position of the Fund as of February 28, 2019, and the results of its operations for the year then ended, the changes in its net assets for each of the two years in the period then ended, and the financial highlights for each of the three years in the period then ended and for the period from October 8, 2015 (commencement of operations) to February 29, 2016, in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

These financial statements and financial highlights are the responsibility of the Fund's management. Our responsibility is to express an opinion on the Fund's financial statements and financial highlights based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Fund in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements and financial highlights are free of material misstatement, whether due to error or fraud. The Fund is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Fund’s internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the financial statements and financial highlights, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements and financial highlights. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements and financial highlights. Our procedures included confirmation of securities owned as of February 28, 2019, by correspondence with the custodians and brokers; when replies were not received from brokers, we performed other auditing procedures. We believe that our audits provide a reasonable basis for our opinion.

/s/ Deloitte & Touche LLP

Boston, Massachusetts

April 11, 2019

We have served as the auditor of one or more of the Fidelity investment companies since 1999.

Trustees and Officers

The Trustees, Members of the Advisory Board (if any), and officers of the trust and fund, as applicable, are listed below. The Board of Trustees governs the fund and is responsible for protecting the interests of shareholders. The Trustees are experienced executives who meet periodically throughout the year to oversee the fund's activities, review contractual arrangements with companies that provide services to the fund, oversee management of the risks associated with such activities and contractual arrangements, and review the fund's performance. Except for Jonathan Chiel, each of the Trustees oversees 260 funds. Mr. Chiel oversees 155 funds.

The Trustees hold office without limit in time except that (a) any Trustee may resign; (b) any Trustee may be removed by written instrument, signed by at least two-thirds of the number of Trustees prior to such removal; (c) any Trustee who requests to be retired or who has become incapacitated by illness or injury may be retired by written instrument signed by a majority of the other Trustees; and (d) any Trustee may be removed at any special meeting of shareholders by a two-thirds vote of the outstanding voting securities of the trust. Each Trustee who is not an interested person (as defined in the 1940 Act) of the trust and the fund is referred to herein as an Independent Trustee. Each Independent Trustee shall retire not later than the last day of the calendar year in which his or her 75th birthday occurs. The Independent Trustees may waive this mandatory retirement age policy with respect to individual Trustees. Officers and Advisory Board Members hold office without limit in time, except that any officer or Advisory Board Member may resign or may be removed by a vote of a majority of the Trustees at any regular meeting or any special meeting of the Trustees. Except as indicated, each individual has held the office shown or other offices in the same company for the past five years.

The fund’s Statement of Additional Information (SAI) includes more information about the Trustees. To request a free copy, call Fidelity at 1-800-544-3455.

Experience, Skills, Attributes, and Qualifications of the Trustees. The Governance and Nominating Committee has adopted a statement of policy that describes the experience, qualifications, attributes, and skills that are necessary and desirable for potential Independent Trustee candidates (Statement of Policy). The Board believes that each Trustee satisfied at the time he or she was initially elected or appointed a Trustee, and continues to satisfy, the standards contemplated by the Statement of Policy. The Governance and Nominating Committee also engages professional search firms to help identify potential Independent Trustee candidates who have the experience, qualifications, attributes, and skills consistent with the Statement of Policy. From time to time, additional criteria based on the composition and skills of the current Independent Trustees, as well as experience or skills that may be appropriate in light of future changes to board composition, business conditions, and regulatory or other developments, have also been considered by the professional search firms and the Governance and Nominating Committee. In addition, the Board takes into account the Trustees' commitment and participation in Board and committee meetings, as well as their leadership of standing and ad hoc committees throughout their tenure.

In determining that a particular Trustee was and continues to be qualified to serve as a Trustee, the Board has considered a variety of criteria, none of which, in isolation, was controlling. The Board believes that, collectively, the Trustees have balanced and diverse experience, qualifications, attributes, and skills, which allow the Board to operate effectively in governing the fund and protecting the interests of shareholders. Information about the specific experience, skills, attributes, and qualifications of each Trustee, which in each case led to the Board's conclusion that the Trustee should serve (or continue to serve) as a trustee of the fund, is provided below.

Board Structure and Oversight Function. Abigail P. Johnson is an interested person and currently serves as Chairman. The Trustees have determined that an interested Chairman is appropriate and benefits shareholders because an interested Chairman has a personal and professional stake in the quality and continuity of services provided to the fund. Independent Trustees exercise their informed business judgment to appoint an individual of their choosing to serve as Chairman, regardless of whether the Trustee happens to be independent or a member of management. The Independent Trustees have determined that they can act independently and effectively without having an Independent Trustee serve as Chairman and that a key structural component for assuring that they are in a position to do so is for the Independent Trustees to constitute a substantial majority for the Board. The Independent Trustees also regularly meet in executive session. Arthur E. Johnson serves as Chairman of the Independent Trustees and as such (i) acts as a liaison between the Independent Trustees and management with respect to matters important to the Independent Trustees and (ii) with management prepares agendas for Board meetings.

Fidelity^® funds are overseen by different Boards of Trustees. The fund's Board oversees Fidelity's investment-grade bond, money market, asset allocation and certain equity funds, and other Boards oversee Fidelity's high income and other equity funds. The asset allocation funds may invest in Fidelity^® funds that are overseen by such other Boards. The use of separate Boards, each with its own committee structure, allows the Trustees of each group of Fidelity^® funds to focus on the unique issues of the funds they oversee, including common research, investment, and operational issues. On occasion, the separate Boards establish joint committees to address issues of overlapping consequences for the Fidelity^® funds overseen by each Board.

The Trustees operate using a system of committees to facilitate the timely and efficient consideration of all matters of importance to the Trustees, the fund, and fund shareholders and to facilitate compliance with legal and regulatory requirements and oversight of the fund's activities and associated risks. The Board, acting through its committees, has charged FMR and its affiliates with (i) identifying events or circumstances the occurrence of which could have demonstrably adverse effects on the fund's business and/or reputation; (ii) implementing processes and controls to lessen the possibility that such events or circumstances occur or to mitigate the effects of such events or circumstances if they do occur; and (iii) creating and maintaining a system designed to evaluate continuously business and market conditions in order to facilitate the identification and implementation processes described in (i) and (ii) above. Because the day-to-day operations and activities of the fund are carried out by or through FMR, its affiliates, and other service providers, the fund's exposure to risks is mitigated but not eliminated by the processes overseen by the Trustees. While each of the Board's committees has responsibility for overseeing different aspects of the fund's activities, oversight is exercised primarily through the Operations and Audit Committees. In addition, an ad hoc Board committee of Independent Trustees has worked with FMR to enhance the Board's oversight of investment and financial risks, legal and regulatory risks, technology risks, and operational risks, including the development of additional risk reporting to the Board. Appropriate personnel, including but not limited to the fund's Chief Compliance Officer (CCO), FMR's internal auditor, the independent accountants, the fund's Treasurer and portfolio management personnel, make periodic reports to the Board's committees, as appropriate, including an annual review of Fidelity's risk management program for the Fidelity^® funds. The responsibilities of each standing committee, including their oversight responsibilities, are described further under "Standing Committees of the Trustees."

Interested Trustees*:

Correspondence intended for a Trustee who is an interested person may be sent to Fidelity Investments, 245 Summer Street, Boston, Massachusetts 02210.

Name, Year of Birth; Principal Occupations and Other Relevant Experience+

Jonathan Chiel (1957)

Year of Election or Appointment: 2016

Trustee

Mr. Chiel also serves as Trustee of other Fidelity^® funds. Mr. Chiel is Executive Vice President and General Counsel for FMR LLC (diversified financial services company, 2012-present). Previously, Mr. Chiel served as general counsel (2004-2012) and senior vice president and deputy general counsel (2000-2004) for John Hancock Financial Services; a partner with Choate, Hall & Stewart (1996-2000) (law firm); and an Assistant United States Attorney for the United States Attorney’s Office of the District of Massachusetts (1986-95), including Chief of the Criminal Division (1993-1995). Mr. Chiel is a director on the boards of the Boston Bar Foundation and the Maimonides School.

Abigail P. Johnson (1961)

Year of Election or Appointment: 2009

Trustee

Chairman of the Board of Trustees

Ms. Johnson also serves as Trustee of other Fidelity^® funds. Ms. Johnson serves as Chairman (2016-present), Chief Executive Officer (2014-present), and Director (2007-present) of FMR LLC (diversified financial services company), President of Fidelity Financial Services (2012-present) and President of Personal, Workplace and Institutional Services (2005-present). Ms. Johnson is Chairman and Director of FMR Co., Inc. (investment adviser firm, 2011-present) and Chairman and Director of FMR (investment adviser firm, 2011-present). Previously, Ms. Johnson served as Vice Chairman (2007-2016) and President (2013-2016) of FMR LLC, President and a Director of FMR (2001-2005), a Trustee of other investment companies advised by FMR, Fidelity Investments Money Management, Inc. (investment adviser firm), and FMR Co., Inc. (2001-2005), Senior Vice President of the Fidelity^® funds (2001-2005), and managed a number of Fidelity^® funds. Ms. Abigail P. Johnson and Mr. Arthur E. Johnson are not related.

Jennifer Toolin McAuliffe (1959)

Year of Election or Appointment: 2016

Trustee

Ms. McAuliffe also serves as Trustee of other Fidelity^® funds. Ms. McAuliffe previously served as a Member of the Advisory Board of certain Fidelity® funds (2016) and as Co-Head of Fixed Income of Fidelity Investments Limited (now known as FIL Limited (FIL)) (diversified financial services company). Earlier roles at FIL included Director of Research for FIL’s credit and quantitative teams in London, Hong Kong and Tokyo. Ms. McAuliffe also was the Director of Research for taxable and municipal bonds at Fidelity Investments Money Management, Inc. Ms. McAuliffe is also a director or trustee of several not-for-profit entities.

* Determined to be an “Interested Trustee” by virtue of, among other things, his or her affiliation with the trust or various entities under common control with FMR.

+ The information includes the Trustee's principal occupation during the last five years and other information relating to the experience, attributes, and skills relevant to the Trustee's qualifications to serve as a Trustee, which led to the conclusion that the Trustee should serve as a Trustee for the fund.

Independent Trustees:

Correspondence intended for an Independent Trustee may be sent to Fidelity Investments, P.O. Box 55235, Boston, Massachusetts 02205-5235.

Name, Year of Birth; Principal Occupations and Other Relevant Experience+

Elizabeth S. Acton (1951)

Year of Election or Appointment: 2013

Trustee

Ms. Acton also serves as Trustee of other Fidelity^® funds. Prior to her retirement in April 2012, Ms. Acton was Executive Vice President, Finance (2011-2012), Executive Vice President, Chief Financial Officer (2002-2011), and Treasurer (2004-2005) of Comerica Incorporated (financial services). Prior to joining Comerica, Ms. Acton held a variety of positions at Ford Motor Company (1983-2002), including Vice President and Treasurer (2000-2002) and Executive Vice President and Chief Financial Officer of Ford Motor Credit Company (1998-2000). Ms. Acton currently serves as a member of the Board of Directors and Audit and Finance Committees of Beazer Homes USA, Inc. (homebuilding, 2012-present). Previously, Ms. Acton served as a Member of the Advisory Board of certain Fidelity^® funds (2013-2016).

Ann E. Dunwoody (1953)

Year of Election or Appointment: 2018

Trustee

General Dunwoody also serves as Trustee of other Fidelity^® funds. General Dunwoody (United States Army, Retired) was the first woman in U.S. military history to achieve the rank of four-star general and prior to her retirement in 2012 held a variety of positions within the U.S. Army, including Commanding General, U.S. Army Material Command (2008-2012). She is the President of First to Four LLC (leadership and mentoring services, 2012-present). She also serves as a member of the Board of Directors and Nominating and Corporate Governance Committee of L3 Technologies, Inc. (communication, electronic, sensor, and aerospace systems, 2013-present), Board of Directors and Nomination and Corporate Governance Committees of Kforce Inc. (professional staffing services, 2016-present) and Board of Directors of Automattic Inc. (software engineering, 2018-present). Previously, General Dunwoody served as a Member of the Advisory Board of certain Fidelity^® funds (2018), a member of the Board of Directors and Audit and Sustainability and Corporate Responsibility Committees of Republic Services, Inc. (waste collection, disposal and recycling, 2013-2016). Ms. Dunwoody also serves on several boards for non-profit organizations, including as a member of the Board of Directors, Chair of the Nomination and Governance Committee and member of the Audit Committee of Logistics Management Institute (consulting non-profit, 2012-present), a member of the Board of Directors of the Army Historical Foundation (2015-present), a member of the Council of Trustees for the Association of the United States Army (advocacy non-profit, 2013-present) and a member of the Board of Trustees of Florida Institute of Technology (2015-present) and ThanksUSA (military family education non-profit, 2014-present).

John Engler (1948)

Year of Election or Appointment: 2014

Trustee

Mr. Engler also serves as Trustee of other Fidelity^® funds. He serves on the board of directors for Universal Forest Products (manufacturer and distributor of wood and wood-alternative products, 2003-present) and K12 Inc. (technology-based education company, 2012-present). Previously, Mr. Engler served as interim president of Michigan State University (2018-2019), a Member of the Advisory Board of certain Fidelity^® funds (2014-2016), president of the Business Roundtable (2011-2017), a trustee of The Munder Funds (2003-2014), president and CEO of the National Association of Manufacturers (2004-2011), member of the Board of Trustees of the Annie E. Casey Foundation (2004-2015), and as governor of Michigan (1991-2003). He is a past chairman of the National Governors Association.

Robert F. Gartland (1951)

Year of Election or Appointment: 2010

Trustee

Mr. Gartland also serves as Trustee of other Fidelity^® funds. Mr. Gartland is Chairman and an investor in Gartland & Mellina Group Corp. (consulting, 2009-present). Previously, Mr. Gartland served as a partner and investor of Vietnam Partners LLC (investments and consulting, 2008-2011). Prior to his retirement, Mr. Gartland held a variety of positions at Morgan Stanley (financial services, 1979-2007), including Managing Director (1987-2007), and Chase Manhattan Bank (1975-1978).

Arthur E. Johnson (1947)

Year of Election or Appointment: 2008

Trustee

Chairman of the Independent Trustees

Mr. Johnson also serves as Trustee of other Fidelity^® funds. Mr. Johnson serves as a member of the Board of Directors of Eaton Corporation plc (diversified power management, 2009-present) and Booz Allen Hamilton (management consulting, 2011-present). Prior to his retirement, Mr. Johnson served as Senior Vice President of Corporate Strategic Development of Lockheed Martin Corporation (defense contractor, 1999-2009). Mr. Johnson previously served as Vice Chairman (2015-2018) of the Independent Trustees of certain Fidelity^® funds and on the Board of Directors of IKON Office Solutions, Inc. (1999-2008), AGL Resources, Inc. (holding company, 2002-2016), and Delta Airlines (2005-2007). Mr. Arthur E. Johnson is not related to Ms. Abigail P. Johnson.

Michael E. Kenneally (1954)

Year of Election or Appointment: 2009

Trustee

Vice Chairman of the Independent Trustees

Mr. Kenneally also serves as Trustee of other Fidelity^® funds. Prior to his retirement, Mr. Kenneally served as Chairman and Global Chief Executive Officer of Credit Suisse Asset Management. Before joining Credit Suisse, he was an Executive Vice President and Chief Investment Officer for Bank of America Corporation. Earlier roles at Bank of America included Director of Research, Senior Portfolio Manager and Research Analyst, and Mr. Kenneally was awarded the Chartered Financial Analyst (CFA) designation in 1991.

Marie L. Knowles (1946)

Year of Election or Appointment: 2001

Trustee

Ms. Knowles also serves as Trustee of other Fidelity^® funds. Prior to Ms. Knowles' retirement in June 2000, she served as Executive Vice President and Chief Financial Officer of Atlantic Richfield Company (ARCO) (diversified energy, 1996-2000). From 1993 to 1996, she was a Senior Vice President of ARCO and President of ARCO Transportation Company (pipeline and tanker operations). Ms. Knowles currently serves as a Director and Chairman of the Audit Committee of McKesson Corporation (healthcare service, since 2002). Ms. Knowles is a member of the Board of the Santa Catalina Island Company (real estate, 2009-present). Ms. Knowles is a Member of the Investment Company Institute Board of Governors and a Member of the Governing Council of the Independent Directors Council (2014-present). She also serves as a member of the Advisory Board for the School of Engineering of the University of Southern California. Previously, Ms. Knowles served as a Director of Phelps Dodge Corporation (copper mining and manufacturing, 1994-2007), URS Corporation (engineering and construction, 2000-2003) and America West (airline, 1999-2002). Ms. Knowles previously served as Chairman (2015-2018) and Vice Chairman (2012-2015) of the Independent Trustees of certain Fidelity^® funds.

Mark A. Murray (1954)

Year of Election or Appointment: 2016

Trustee

Mr. Murray also serves as Trustee of other Fidelity^® funds. Mr. Murray is Vice Chairman (2013-present) of Meijer, Inc. (regional retail chain). Previously, Mr. Murray served as a Member of the Advisory Board of certain Fidelity® funds (2016) and as Co-Chief Executive Officer (2013-2016) and President (2006-2013) of Meijer, Inc. Mr. Murray serves as a member of the Board of Directors and Nuclear Review and Public Policy and Responsibility Committees of DTE Energy Company (diversified energy company, 2009-present). Mr. Murray also serves as a member of the Board of Directors of Spectrum Health (not-for-profit health system, 2015-present). Mr. Murray previously served as President of Grand Valley State University (2001-2006), Treasurer for the State of Michigan (1999-2001), Vice President of Finance and Administration for Michigan State University (1998-1999), and a member of the Board of Directors and Audit Committee and Chairman of the Nominating and Corporate Governance Committee of Universal Forest Products, Inc. (manufacturer and distributor of wood and wood-alternative products, 2004-2016). Mr. Murray is also a director or trustee of many community and professional organizations.

Advisory Board Members and Officers:

Correspondence intended for an officer may be sent to Fidelity Investments, 245 Summer Street, Boston, Massachusetts 02210. Officers appear below in alphabetical order.

Name, Year of Birth; Principal Occupation

Elizabeth Paige Baumann (1968)

Year of Election or Appointment: 2017

Anti-Money Laundering (AML) Officer

Ms. Baumann also serves as AML Officer of other funds. She is Chief AML Officer (2012-present) and Senior Vice President (2014-present) of FMR LLC (diversified financial services company) and is an employee of Fidelity Investments. Previously, Ms. Baumann served as AML Officer of the funds (2012-2016), and Vice President (2007-2014) and Deputy Anti-Money Laundering Officer (2007-2012) of FMR LLC.

Craig S. Brown (1977)

Year of Election or Appointment: 2019

Assistant Treasurer

Mr. Brown also serves as Assistant Treasurer of other funds. Mr. Brown is an employee of Fidelity Investments (2013-present).

John J. Burke III (1964)

Year of Election or Appointment: 2018

Chief Financial Officer

Mr. Burke also serves as Chief Financial Officer of other funds. Mr. Burke serves as Head of Investment Operations for Fidelity Fund and Investment Operations (2018-present) and is an employee of Fidelity Investments (1998-present). Previously Mr. Burke served as head of Asset Management Investment Operations (2012-2018).

William C. Coffey (1969)

Year of Election or Appointment: 2018

Secretary and Chief Legal Officer (CLO)

Mr. Coffey also serves as Secretary and CLO of other funds. Mr. Coffey serves as CLO, Secretary, and Senior Vice President of Fidelity Management & Research Company and FMR Co., Inc. (investment adviser firms, 2018-present); Secretary of Fidelity SelectCo, LLC and Fidelity Investments Money Management, Inc. (investment adviser firms, 2018-present); and CLO of Fidelity Management & Research (Hong Kong) Limited, FMR Investment Management (UK) Limited, and Fidelity Management & Research (Japan) Limited (investment adviser firms, 2018-present). He is Senior Vice President and Deputy General Counsel of FMR LLC (diversified financial services company, 2010-present), and is an employee of Fidelity Investments. Previously, Mr. Coffey served as Assistant Secretary of certain funds (2009-2018) and as Vice President and Associate General Counsel of FMR LLC (2005-2009).

Jonathan Davis (1968)

Year of Election or Appointment: 2010

Assistant Treasurer

Mr. Davis also serves as Assistant Treasurer of other funds. Mr. Davis serves as Assistant Treasurer of FMR Capital, Inc. (2017-present) and is an employee of Fidelity Investments. Previously, Mr. Davis served as Vice President and Associate General Counsel of FMR LLC (diversified financial services company, 2003-2010).

Adrien E. Deberghes (1967)

Year of Election or Appointment: 2010

Assistant Treasurer

Mr. Deberghes also serves as an officer of other funds. He serves as Assistant Treasurer of FMR Capital, Inc. (2017-present), Executive Vice President of Fidelity Investments Money Management, Inc. (FIMM) (investment adviser firm, 2016-present), and is an employee of Fidelity Investments (2008-present). Previously, Mr. Deberghes served as President and Treasurer of certain Fidelity^® funds (2013-2018). Prior to joining Fidelity Investments, Mr. Deberghes was Senior Vice President of Mutual Fund Administration at State Street Corporation (2007-2008), Senior Director of Mutual Fund Administration at Investors Bank & Trust (2005-2007), and Director of Finance for Dunkin' Brands (2000-2005). Previously, Mr. Deberghes served in other fund officer roles.

Laura M. Del Prato (1964)

Year of Election or Appointment: 2018

President and Treasurer

Ms. Del Prato also serves as an officer of other funds. Ms. Del Prato is an employee of Fidelity Investments (2017-present). Prior to joining Fidelity Investments, Ms. Del Prato served as a Managing Director and Treasurer of the JPMorgan Mutual Funds (2014-2017). Prior to JPMorgan, Ms. Del Prato served as a partner at Cohen Fund Audit Services (accounting firm, 2012-2013) and KPMG LLP (accounting firm, 2004-2012).

Colm A. Hogan (1973)

Year of Election or Appointment: 2016

Assistant Treasurer

Mr. Hogan also serves as an officer of other funds. Mr. Hogan serves as Assistant Treasurer of FMR Capital, Inc. (2017-present) and is an employee of Fidelity Investments (2005-present). Previously, Mr. Hogan served as Assistant Treasurer of certain Fidelity^® funds (2016-2018).

Chris Maher (1972)

Year of Election or Appointment: 2013

Assistant Treasurer

Mr. Maher serves as Assistant Treasurer of other funds. Mr. Maher is Vice President of Valuation Oversight, serves as Assistant Treasurer of FMR Capital, Inc. (2017-present), and is an employee of Fidelity Investments. Previously, Mr. Maher served as Vice President of Asset Management Compliance (2013), Vice President of the Program Management Group of FMR (investment adviser firm, 2010-2013), and Vice President of Valuation Oversight (2008-2010).

John B. McGinty, Jr. (1962)

Year of Election or Appointment: 2016

Chief Compliance Officer

Mr. McGinty also serves as Chief Compliance Officer of other funds. Mr. McGinty is Senior Vice President of Asset Management Compliance for Fidelity Investments and is an employee of Fidelity Investments (2016-present). Mr. McGinty previously served as Vice President, Senior Attorney at Eaton Vance Management (investment management firm, 2015-2016), and prior to Eaton Vance as global CCO for all firm operations and registered investment companies at GMO LLC (investment management firm, 2009-2015). Before joining GMO LLC, Mr. McGinty served as Senior Vice President, Deputy General Counsel for Fidelity Investments (2007-2009).

Jason P. Pogorelec (1975)

Year of Election or Appointment: 2015

Assistant Secretary

Mr. Pogorelec also serves as Assistant Secretary of other funds. Mr. Pogorelec serves as Vice President, Associate General Counsel (2010-present) and is an employee of Fidelity Investments (2006-present).

Nancy D. Prior (1967)

Year of Election or Appointment: 2014

Vice President

Ms. Prior also serves as Vice President of other funds. Ms. Prior serves as President Fixed Income, High Income/Emerging Market Debt and Multi Asset Class Strategies of FIAM LLC (2018-present), President (2016-present) and Director (2014-present) of Fidelity Investments Money Management, Inc. (FIMM) (investment adviser firm), President, Fixed Income (2014-present), and is an employee of Fidelity Investments (2002-present). Previously, Ms. Prior served as Vice Chairman of FIAM LLC (investment adviser firm, 2014-2018), a Director of FMR Investment Management (UK) Limited (investment adviser firm, 2015-2018), President Multi-Asset Class Strategies of FMR's Global Asset Allocation Division (2017-2018), Vice President of Fidelity's Money Market Funds (2012-2014), President, Money Market and Short Duration Bond Group of Fidelity Management & Research (FMR) (investment adviser firm, 2013-2014), President, Money Market Group of FMR (2011-2013), Managing Director of Research (2009-2011), Senior Vice President and Deputy General Counsel (2007-2009), and Assistant Secretary of certain Fidelity^® funds (2008-2009).

Stacie M. Smith (1974)

Year of Election or Appointment: 2013

Assistant Treasurer

Ms. Smith also serves as an officer of other funds. Ms. Smith serves as Assistant Treasurer of FMR Capital, Inc. (2017-present), is an employee of Fidelity Investments (2009-present), and has served in other fund officer roles. Prior to joining Fidelity Investments, Ms. Smith served as Senior Audit Manager of Ernst & Young LLP (accounting firm, 1996-2009). Previously, Ms. Smith served as Assistant Treasurer (2013-2018) and Deputy Treasurer (2013-2016) of certain Fidelity^® funds.

Marc L. Spector (1972)

Year of Election or Appointment: 2016

Deputy Treasurer

Mr. Spector also serves as an officer of other funds. Mr. Spector serves as Assistant Treasurer of FMR Capital, Inc. (2017-present) and is an employee of Fidelity Investments (2016-present). Prior to joining Fidelity Investments, Mr. Spector served as Director at the Siegfried Group (accounting firm, 2013-2016), and prior to Siegfried Group as audit senior manager at Deloitte & Touche (accounting firm, 2005-2013).

Jim Wegmann (1979)

Year of Election or Appointment: 2019

Assistant Treasurer

Mr. Wegmann also serves as Assistant Treasurer of other funds. Mr. Wegmann is an employee of Fidelity Investments (2011-present).

Shareholder Expense Example

As a shareholder of the Fund, you incur two types of costs: (1) transaction costs, and (2) ongoing costs, including management fees and other Fund expenses. This Example is intended to help you understand your ongoing costs (in dollars) of investing in the Fund and to compare these costs with the ongoing costs of investing in other mutual funds.

The Example is based on an investment of $1,000 invested at the beginning of the period and held for the entire period (September 1, 2018 to February 28, 2019).

Actual Expenses

The first line of the accompanying table provides information about actual account values and actual expenses. You may use the information in this line, together with the amount you invested, to estimate the expenses that you paid over the period. Simply divide your account value by $1,000.00 (for example, an $8,600 account value divided by $1,000.00 = 8.6), then multiply the result by the number in the first line under the heading entitled "Expenses Paid During Period" to estimate the expenses you paid on your account during this period. In addition, the Fund, as a shareholder in the underlying Fidelity Central Funds, will indirectly bear its pro-rata share of the fees and expenses incurred by the underlying Fidelity Central Funds. These fees and expenses are not included in the Fund's annualized expense ratio used to calculate the expense estimate in the table below.

Hypothetical Example for Comparison Purposes

The second line of the accompanying table provides information about hypothetical account values and hypothetical expenses based on the Fund's actual expense ratio and an assumed rate of return of 5% per year before expenses, which is not the Fund's actual return. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period. You may use this information to compare the ongoing costs of investing in the Fund and other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of the other funds. In addition, the Fund, as a shareholder in the underlying Fidelity Central Funds, will indirectly bear its pro-rata share of the fees and expenses incurred by the underlying Fidelity Central Funds. These fees and expenses are not included in the Fund's annualized expense ratio used to calculate the expense estimate in the table below.

Please note that the expenses shown in the table are meant to highlight your ongoing costs only and do not reflect any transaction costs. Therefore, the second line of the table is useful in comparing ongoing costs only, and will not help you determine the relative total costs of owning different funds.

	Annualized Expense Ratio-^A	Beginning Account Value September 1, 2018	Ending Account Value February 28, 2019	Expenses Paid During Period-^B September 1, 2018 to February 28, 2019
Actual	.03%	$1,000.00	$1,006.60	$.15
Hypothetical-^C		$1,000.00	$1,024.65	$.15

^A Annualized expense ratio reflects expenses net of applicable fee waivers.

^B Expenses are equal to the Fund's annualized expense ratio, multiplied by the average account value over the period, multiplied by 181/365 (to reflect the one-half year period).

^C 5% return per year before expenses

Distributions (Unaudited)

A total of 99.94% of the dividends distributed during the fiscal year was derived from interest on U.S. Government securities which is generally exempt from state income tax.

The fund will notify shareholders in January 2020 of amounts for use in preparing 2019 income tax returns.

Board Approval of Investment Advisory Contracts and Management Fees

Fidelity SAI Long-Term Treasury Bond Index Fund

Each year, the Board of Trustees, including the Independent Trustees (together, the Board), votes on the renewal of the management contract with Fidelity Management & Research Company (FMR) and the sub-advisory agreements (together, the Advisory Contracts) for the fund. FMR and the sub-advisers are referred to herein as the Investment Advisers. The Board, assisted by the advice of fund counsel and Independent Trustees' counsel, requests and considers a broad range of information relevant to the renewal of the Advisory Contracts throughout the year.

The Board meets regularly and, at each of its meetings, covers an extensive agenda of topics and materials and considers factors that are relevant to its annual consideration of the renewal of the fund's Advisory Contracts, including the services and support provided to the fund and its shareholders. The Board has established four standing committees (Committees) — Operations, Audit, Fair Valuation, and Governance and Nominating — each composed of and chaired by Independent Trustees with varying backgrounds, to which the Board has assigned specific subject matter responsibilities in order to enhance effective decision-making by the Board. The Operations Committee, of which all of the Independent Trustees are members, meets regularly throughout the year and considers, among other matters, information specifically related to the annual consideration of the renewal of the fund's Advisory Contracts. The Board, acting directly and through its Committees, requests and receives information concerning the annual consideration of the renewal of the fund's Advisory Contracts. The Board also meets as needed to review matters specifically related to the Board's annual consideration of the renewal of the Advisory Contracts. Members of the Board may also meet with trustees of other Fidelity funds through joint ad hoc committees to discuss certain matters relevant to all of the Fidelity funds.

At its September 2018 meeting, the Board unanimously determined to renew the fund's Advisory Contracts. In reaching its determination, the Board considered all factors it believed relevant, including (i) the nature, extent, and quality of the services to be provided to the fund and its shareholders (including the investment performance of the fund); (ii) the competitiveness of the fund's management fee and total expense ratio relative to peer funds; (iii) the total costs of the services to be provided by and the profits to be realized by Fidelity from its relationships with the fund; and (iv) the extent to which, if any, economies of scale exist and would be realized as the fund grows, and whether any economies of scale are appropriately shared with fund shareholders.

In considering whether to renew the Advisory Contracts for the fund, the Board reached a determination, with the assistance of fund counsel and Independent Trustees' counsel and through the exercise of its business judgment, that the renewal of the Advisory Contracts was in the best interests of the fund and its shareholders and that the compensation payable under the Advisory Contracts was fair and reasonable. The Board's decision to renew the Advisory Contracts was not based on any single factor, but rather was based on a comprehensive consideration of all the information provided to the Board at its meetings throughout the year. The Board, in reaching its determination to renew the Advisory Contracts, was aware that shareholders of the fund have a broad range of investment choices available to them, including a wide choice among funds offered by Fidelity's competitors, and that the fund's shareholders, who have the opportunity to review and weigh the disclosure provided by the fund in its prospectus and other public disclosures, have chosen to invest in this fund, which is part of the Fidelity family of funds.

Nature, Extent, and Quality of Services Provided. The Board considered Fidelity's staffing as it relates to the fund, including the backgrounds of investment personnel of Fidelity, and also considered the fund's investment objective, strategies, and related investment philosophy. The Independent Trustees also had discussions with senior management of Fidelity's investment operations and investment groups. The Board considered the structure of the investment personnel compensation program and whether this structure provides appropriate incentives to act in the best interests of the fund. Additionally, the Board considered the portfolio managers' investments, if any, in the funds that they manage.

Resources Dedicated to Investment Management and Support Services. The Board reviewed the general qualifications and capabilities of Fidelity's investment staff, including its size, education, experience, and resources, as well as Fidelity's approach to recruiting, managing, and compensating investment personnel. The Board noted that Fidelity has continued to increase the resources devoted to non-U.S. offices, including expansion of Fidelity's global investment organization. The Board also noted that Fidelity's analysts have extensive resources, tools and capabilities that allow them to conduct sophisticated quantitative and fundamental analysis, as well as credit analysis of issuers, counterparties and guarantors. Further, the Board considered that Fidelity's investment professionals have sufficient access to global information and data so as to provide competitive investment results over time, and that those professionals also have access to sophisticated tools that permit them to assess portfolio construction and risk and performance attribution characteristics continuously, as well as to transmit new information and research conclusions rapidly around the world. Additionally, in its deliberations, the Board considered Fidelity's trading, risk management, compliance, and technology and operations capabilities and resources, which are integral parts of the investment management process.

Shareholder and Administrative Services. The Board considered (i) the nature, extent, quality, and cost of advisory, administrative, and shareholder services performed by the Investment Advisers and their affiliates under the Advisory Contracts and under separate agreements covering transfer agency, pricing and bookkeeping, and securities lending services for the fund; (ii) the nature and extent of the supervision of third party service providers, principally custodians, subcustodians, and pricing vendors; and (iii) the resources devoted to, and the record of compliance with, the fund's compliance policies and procedures.

The Board noted that the growth of fund assets over time across the complex allows Fidelity to reinvest in the development of services designed to enhance the value and convenience of the Fidelity funds as investment vehicles. These services include 24-hour access to account information and market information through telephone representatives and over the Internet, investor education materials and asset allocation tools, and the expanded availability of Fidelity Investor Centers.

Investment in a Large Fund Family. The Board considered the benefits to shareholders of investing in a Fidelity fund, including the benefits of investing in a fund that is part of a large family of funds offering a variety of investment disciplines and providing a large variety of mutual fund investor services. The Board noted that Fidelity had taken, or had made recommendations that resulted in the Fidelity funds taking, a number of actions over the previous year that benefited particular funds, including: (i) continuing to dedicate additional resources to Fidelity's investment research process, which includes meetings with management of issuers of securities in which the funds invest, and to the support of the senior management team that oversees asset management; (ii) continuing efforts to enhance Fidelity's global research capabilities; (iii) launching new funds and making other enhancements to meet client needs; (iv) launching new share classes of existing funds; (v) eliminating purchase minimums and broadening eligibility requirements for certain funds and share classes; (vi) reducing management fees and total expenses for certain growth equity funds and index funds; (vii) lowering expense caps for certain existing funds and classes, and converting certain voluntary expense caps to contractual caps, to reduce expenses borne by shareholders; (viii) eliminating short-term redemption fees for funds that had such fees; (ix) rationalizing product lines and gaining increased efficiencies from fund mergers and share class consolidations; (x) continuing to develop, acquire and implement systems and technology to improve services to the funds and shareholders, strengthen information security, and increase efficiency; and (xi) continuing to implement enhancements to further strengthen Fidelity's product line to increase investors' probability of success in achieving their investment goals, including retirement income goals.

The Board took into account discussions that occur at Board meetings throughout the year with representatives of the Investment Advisers about fund investment performance. In this regard the Board noted that as part of regularly scheduled fund reviews and other reports to the Board on fund performance, the Board considers annualized return information for the fund for different time periods, measured against the securities market index the fund seeks to track. The Board also periodically considers the fund's tracking error versus its benchmark index. In its evaluation of fund investment performance at meetings throughout the year, the Board gave particular attention to information indicating underperformance of certain Fidelity funds for specific time periods and discussed with the Investment Advisers the reasons for such underperformance.

In addition to reviewing absolute and relative fund performance, the Independent Trustees periodically consider the appropriateness of fund performance metrics in evaluating the results achieved. In general, the Independent Trustees believe that an index fund's performance should be evaluated based on gross performance (before fees and expenses but after transaction costs) compared to a fund's benchmark index, over appropriate time periods, taking into account relevant factors including the following: general market conditions; the characteristics of the fund's benchmark index; the extent to which statistical sampling is employed; and fund cash flows and other factors. Depending on the circumstances, the Independent Trustees may be satisfied with a fund's performance notwithstanding that it lags its benchmark index for certain periods.

The Independent Trustees recognize that shareholders evaluate performance on a net basis (after fees and expenses) over their own holding periods, for which one-, three-, and five-year periods are often used as a proxy. For this reason, the performance information reviewed by the Board also included net calendar year total return information for the fund and its benchmark index for the most recent one-year period.

Based on its review, the Board concluded that the nature, extent, and quality of services provided to the fund under the Advisory Contracts should continue to benefit the shareholders of the fund.

Competitiveness of Management Fee and Total Expense Ratio. The Board considered the fund's management fee and total expense ratio compared to "mapped groups" of competitive funds and classes created for the purpose of facilitating the Trustees' competitive analysis of management fees and total expenses. Fidelity creates "mapped groups" by combining similar Lipper investment objective categories that have comparable investment mandates. Combining Lipper investment objective categories aids the Board's management fee and total expense ratio comparisons by broadening the competitive group used for comparison.

Management Fee. The Board considered two proprietary management fee comparisons for the 12-month (or shorter) periods shown in basis points (BP) in the chart below. The group of Lipper funds used by the Board for management fee comparisons is referred to below as the "Total Mapped Group." The Total Mapped Group comparison focuses on a fund's standing in terms of gross management fees before expense reimbursements or caps relative to the total universe of funds with comparable investment mandates, regardless of whether their management fee structures also are comparable. Funds with comparable investment mandates offer exposure to similar types of securities. Funds with comparable management fee structures have similar management fee contractual arrangements (e.g., flat rate charged for advisory services, all-inclusive fee rate, etc.). "TMG %" represents the percentage of funds in the Total Mapped Group that had management fees that were lower than the fund's. For example, a hypothetical TMG % of 20% would mean that 80% of the funds in the Total Mapped Group had higher, and 20% had lower, management fees than the fund. The fund's actual TMG %s and the number of funds in the Total Mapped Group are in the chart below. The "Asset-Size Peer Group" (ASPG) comparison focuses on a fund's standing relative to a subset of non-Fidelity funds within the Total Mapped Group that are similar in size and management fee structure. For example, if a fund is in the first quartile of the ASPG, the fund's management fee ranks in the least expensive or lowest 25% of funds in the ASPG. The ASPG represents at least 15% of the funds in the Total Mapped Group with comparable asset size and management fee structures, subject to a minimum of 50 funds (or all funds in the Total Mapped Group if fewer than 50). Additional information, such as the ASPG quartile in which the fund's management fee rate ranked, is also included in the chart and was considered by the Board.

Fidelity SAI Long-Term Treasury Bond Index Fund

The Board noted that the fund's management fee rate ranked below the median of its Total Mapped Group and below the median of its ASPG for 2017.

The Board noted that it and the boards of other Fidelity funds formed an ad hoc Committee on Group Fee, which meets periodically, to conduct an in-depth review of the "group fee" component of the management fee of funds with such management fee structures. The Committee's focus included the mechanics of the group fee, the competitive landscape of group fee structures, Fidelity funds with no group fee component (such as the fund) and investment products not included in group fee assets. The Board also considered that, for funds subject to the group fee, FMR agreed to voluntarily waive fees over a specified period of time in amounts designed to account for assets converted from certain funds to certain collective investment trusts.

Based on its review, the Board concluded that the fund's management fee is fair and reasonable in light of the services that the fund receives and the other factors considered.

Total Expense Ratio. In its review of the fund's total expense ratio, the Board considered the fund's management fee rate as well as other fund expenses, such as transfer agent fees, pricing and bookkeeping fees, and custodial, legal, and audit fees. The Board also noted that Fidelity may agree to waive fees and expenses from time to time, and the extent to which, if any, it has done so for the fund. As part of its review, the Board also considered the current and historical total expense ratios of the fund compared to competitive fund median expenses. The fund is compared to those funds and classes in the Total Mapped Group (used by the Board for management fee comparisons) that have a similar sales load structure.

The Board noted that the fund's total expense ratio ranked below the competitive median for 2017.

The Board further considered that FMR has contractually agreed to reimburse the fund to the extent that total operating expenses (excluding interest, certain taxes, certain securities lending costs, brokerage commissions, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses, if any), as a percentage of its average net assets, exceed 0.03% through April 30, 2019.

Fees Charged to Other Fidelity Clients. The Board also considered Fidelity fee structures and other information with respect to clients of Fidelity, such as other funds advised or subadvised by Fidelity, pension plan clients, and other institutional clients with similar mandates. The Board noted that a joint ad hoc committee created by it and the boards of other Fidelity funds periodically reviews and compares Fidelity's institutional investment advisory business with its business of providing services to the Fidelity funds and also noted the most recent findings of the committee. The Board noted that the committee's review included a consideration of the differences in services provided, fees charged, and costs incurred, as well as competition in the markets serving the different categories of clients.

Based on its review of total expense ratios and fees charged to other Fidelity clients, the Board concluded that the fund's total expense ratio was reasonable in light of the services that the fund and its shareholders receive and the other factors considered.

Costs of the Services and Profitability. The Board considered the revenues earned and the expenses incurred by Fidelity in conducting the business of developing, marketing, distributing, managing, administering and servicing the fund and servicing the fund's shareholders. The Board also considered the level of Fidelity's profits in respect of all the Fidelity funds.

On an annual basis, Fidelity presents to the Board information about the profitability of its relationships with the fund. Fidelity calculates profitability information for each fund, as well as aggregate profitability information for groups of Fidelity funds and all Fidelity funds, using a series of detailed revenue and cost allocation methodologies which originate with the books and records of Fidelity on which Fidelity's audited financial statements are based. The Audit Committee of the Board reviews any significant changes from the prior year's methodologies.

PricewaterhouseCoopers LLP (PwC), auditor to Fidelity and certain Fidelity funds, has been engaged annually by the Board as part of the Board's assessment of Fidelity's profitability analysis. PwC's engagement includes the review and assessment of the methodologies used by Fidelity in determining the revenues and expenses attributable to Fidelity's mutual fund business, and completion of agreed-upon procedures in respect of the mathematical accuracy of the fund profitability information and its conformity to established allocation methodologies. After considering PwC's reports issued under the engagement and information provided by Fidelity, the Board concluded that while other allocation methods may also be reasonable, Fidelity's profitability methodologies are reasonable in all material respects.

The Board also reviewed Fidelity's non-fund businesses and potential indirect benefits such businesses may have received as a result of their association with Fidelity's mutual fund business (i.e., fall-out benefits) as well as cases where Fidelity's affiliates may benefit from the fund's business. The Board noted that changes to fall-out benefits year-over-year reflect business developments at Fidelity's various businesses.

The Board considered the costs of the services provided by and the profits realized by Fidelity in connection with the operation of the fund and was satisfied that the profitability was not excessive.

Economies of Scale. The Board considered whether there have been economies of scale in respect of the management of the Fidelity funds, whether the Fidelity funds (including the fund) have appropriately benefited from any such economies of scale, and whether there is potential for realization of any further economies of scale. The Board considered the extent to which the fund will benefit from economies of scale as assets grow through increased services to the fund, through waivers or reimbursements, or through fee or expense ratio reductions. The Board also noted that a committee (the Economies of Scale Committee) created by it and the boards of other Fidelity funds periodically analyzes whether Fidelity attains economies of scale in respect of the management and servicing of the Fidelity funds, whether the Fidelity funds have appropriately benefited from such economies of scale, and whether there is potential for realization of any further economies of scale.

The Board concluded, taking into account the analysis of the Economies of Scale Committee, that economies of scale, if any, are being appropriately shared between fund shareholders and Fidelity.

Additional Information Requested by the Board. In order to develop fully the factual basis for consideration of the Fidelity funds' advisory contracts, the Board requested and received additional information on certain topics, including: (i) Fidelity's fund profitability methodology, profitability trends for certain funds, the allocation of various costs to different funds, and the impact of certain factors on fund profitability results; (ii) portfolio manager changes that have occurred during the past year and the amount of the investment that each portfolio manager has made in the Fidelity fund(s) that he or she manages; (iii) Fidelity's compensation structure for portfolio managers, research analysts, and other key personnel, including its effects on fund profitability, the rationale for the compensation structure, and the extent to which current market conditions have affected retention and recruitment; (iv) the arrangements with and compensation paid to certain fund sub-advisers on behalf of the Fidelity funds and the treatment of such compensation within Fidelity's fund profitability methodology; (v) the terms of Fidelity's voluntary expense limitation agreements; (vi) the methodology with respect to competitive fund data and peer group classifications; (vii) Fidelity's transfer agent fee, expense, and service structures for different funds and classes relative to competitive trends, and the impact of the increased use of omnibus accounts; (viii) new developments in the retail and institutional marketplaces and the competitive positioning of the funds relative to other investment products and services; (ix) the impact of recent changes to the money market fund landscape, including the full implementation of money market fund reform and rising interest rates, on Fidelity's money market funds; (x) the funds' share class structures and distribution channels; and (xi) explanations regarding the relative total expense ratios of certain funds and classes, total expense competitive trends and methodologies for total expense competitive comparisons, and actions that might be taken by Fidelity to reduce total expense ratios for certain classes. In addition, the Board considered its discussions with Fidelity throughout the year regarding enhanced information security initiatives and the funds' fair valuation policies.

Based on its evaluation of all of the conclusions noted above, and after considering all factors it believed relevant, the Board concluded that the advisory fee arrangements are fair and reasonable, and that the fund's Advisory Contracts should be renewed.

Fidelity Investments

SV5-ANN-0419
1.9869414.103

Fidelity® Series Long-Term Treasury Bond Index Fund

Annual Report

February 28, 2019

Account Type	Website	Phone Number
Brokerage, Mutual Fund, or Annuity Contracts:	fidelity.com/mailpreferences	1-800-343-3548
Employer Provided Retirement Accounts:	netbenefits.fidelity.com/preferences (choose 'no' under Required Disclosures to continue to print)	1-800-343-0860
Advisor Sold Accounts Serviced Through Your Financial Intermediary:	Contact Your Financial Intermediary	Your Financial Intermediary's phone number
Advisor Sold Accounts Serviced by Fidelity:	institutional.fidelity.com	1-877-208-0098

Contents

Performance
Management's Discussion of Fund Performance
Investment Summary
Schedule of Investments
Financial Statements
Notes to Financial Statements
Report of Independent Registered Public Accounting Firm
Trustees and Officers
Shareholder Expense Example
Distributions
Board Approval of Investment Advisory Contracts and Management Fees

You may also call 1-800-544-8544 to request a free copy of the proxy voting guidelines.

Standard & Poor's, S&P and S&P 500 are registered service marks of The McGraw-Hill Companies, Inc. and have been licensed for use by Fidelity Distributors Corporation.

Other third-party marks appearing herein are the property of their respective owners.

NOT FDIC INSURED •MAY LOSE VALUE •NO BANK GUARANTEE

Neither the Fund nor Fidelity Distributors Corporation is a bank.

Performance: The Bottom Line

Average Annual Total Returns

For the periods ended February 28, 2019	Past 1 year	Life of fund^A
Fidelity® Series Long-Term Treasury Bond Index	3.84%	(3.79)%

^A From July 7, 2016

$10,000 Over Life of Fund

Let's say hypothetically that $10,000 was invested in Fidelity® Series Long-Term Treasury Bond Index Fund on July 7, 2016, when the fund started.

The chart shows how the value of your investment would have changed, and also shows how the Bloomberg Barclays U.S. Long Treasury Bond Index performed over the same period.

	Period Ending Values
	$9,028	Fidelity® Series Long-Term Treasury Bond Index
	$9,052	Bloomberg Barclays U.S. Long Treasury Bond Index

Management's Discussion of Fund Performance

Comments from Co-Portfolio Managers Brandon Bettencourt and Jay Small: For the fiscal year, the fund gained 3.84%, roughly in line, net of fees, with the 3.99% advance of the benchmark Bloomberg Barclays Long-Term Treasury Bond Index. This result met our goal of producing monthly returns, before expenses, that closely match the benchmark’s returns. We use a method known as stratified sampling, which matches the index’s risk factors, but does not always hold all bonds in the exact proportions of the index. From March through November 2018, U.S. Treasuries were under pressure due to rising interest rates and expectations for further policy rate increases by the Federal Reserve. Another factor weighing on U.S. Treasuries was the Fed’s decision to begin reducing the $4.5 trillion in government securities it accumulated as part of the quantitative easing program it deployed to battle the recession and financial crisis a decade ago. That said, from December through period end, U.S. Treasury prices rallied strongly after the Fed made a dovish pivot, indicating that the case for raising interest rates had weakened somewhat with slowing global economic growth and muted inflation. Moreover, the Fed communicated that it would be patient in assessing the need for further interest rate hikes. Against this backdrop, the yield curve flattened and both intermediate- and long-term U.S. Treasuries outperformed their shorter-term counterparts.

Investment Summary (Unaudited)

Coupon Distribution as of February 28, 2019

	% of fund's investments
2 - 2.99%	28.6
3 - 3.99%	53.1
4 - 4.99%	14.4
5 - 5.99%	1.8
6 - 6.99%	1.4

Coupon distribution shows the range of stated interest rates on the fund's investments, excluding short-term investments.

Asset Allocation (% of fund's net assets)

As of February 28, 2019
	U.S. Treasury Obligations	99.5%
	Short-Term Investments and Net Other Assets (Liabilities)	0.5%

Schedule of Investments February 28, 2019

Showing Percentage of Net Assets

U.S. Government and Government Agency Obligations - 99.5%
	Principal Amount	Value
U.S. Treasury Obligations - 99.5%
U.S. Treasury Bonds:
2.25% 8/15/46	$320,912,000	$270,907,393
2.5% 2/15/45	329,246,000	294,713,754
2.5% 2/15/46	302,647,000	269,876,005
2.5% 5/15/46	319,585,000	284,767,713
2.75% 8/15/42	180,536,000	171,036,703
2.75% 11/15/42	244,706,000	231,533,936
2.75% 8/15/47	307,823,000	287,970,821
2.75% 11/15/47	311,958,000	291,619,801
2.875% 5/15/43	320,933,000	309,813,172
2.875% 8/15/45	301,872,000	290,528,218
2.875% 11/15/46	309,092,000	297,102,612
3% 5/15/42	116,729,000	115,616,427
3% 11/15/44	320,241,000	315,587,498
3% 5/15/45	279,989,000	276,018,843
3% 11/15/45	331,243,000	326,455,505
3% 2/15/47	309,169,000	304,688,464
3% 5/15/47	286,283,000	281,765,096
3% 2/15/48	302,418,000	297,149,310
3% 8/15/48	355,721,000	349,593,151
3% 2/15/49	139,531,000	137,209,118
3.125% 11/15/41	109,683,000	111,182,573
3.125% 2/15/42	130,421,000	132,081,831
3.125% 2/15/43	230,083,000	232,240,028
3.125% 8/15/44	322,391,000	324,834,118
3.125% 5/15/48	341,321,000	343,680,914
3.375% 5/15/44	299,601,000	315,095,989
3.375% 11/15/48	359,128,000	379,665,627
3.5% 2/15/39	94,980,000	103,138,634
3.625% 8/15/43	255,753,000	280,029,556
3.625% 2/15/44	278,514,000	305,125,144
3.75% 8/15/41	131,832,000	147,239,865
3.75% 11/15/43	319,276,000	356,641,269
3.875% 8/15/40	116,679,000	132,813,518
4.25% 5/15/39	108,094,000	129,548,125
4.25% 11/15/40	141,013,000	168,918,150
4.375% 2/15/38	62,432,000	76,023,154
4.375% 11/15/39	86,096,000	104,831,970
4.375% 5/15/40	131,801,000	160,498,609
4.375% 5/15/41	109,841,000	133,950,242
4.5% 2/15/36	118,746,000	145,333,972
4.5% 5/15/38	45,494,000	56,298,825
4.5% 8/15/39	105,499,000	130,567,376
4.625% 2/15/40	154,840,000	194,723,396
4.75% 2/15/37	29,235,000	37,026,813
4.75% 2/15/41	133,276,000	170,598,486
5% 5/15/37	49,394,000	64,439,876
5.375% 2/15/31	101,102,000	127,854,538
6.125% 8/15/29	45,308,000	59,213,662
6.25% 5/15/30	62,820,000	83,881,878
		10,411,431,678
TOTAL U.S. GOVERNMENT AND GOVERNMENT AGENCY OBLIGATIONS
(Cost $10,571,835,810)		10,411,431,678
	Shares	Value

Money Market Funds - 0.8%
Fidelity Cash Central Fund, 2.44% (a)
(Cost $83,535,058)	83,518,354	83,535,058
TOTAL INVESTMENT IN SECURITIES - 100.3%
(Cost $10,655,370,868)		10,494,966,736
NET OTHER ASSETS (LIABILITIES) - (0.3)%		(28,522,856)
NET ASSETS - 100%		$10,466,443,880

Legend

Affiliated Central Funds

Information regarding fiscal year to date income earned by the Fund from investments in Fidelity Central Funds is as follows:

Fund	Income earned
Fidelity Cash Central Fund	$320,920
Total	$320,920

Investment Valuation

	Valuation Inputs at Reporting Date:
Description	Total	Level 1	Level 2	Level 3
Investments in Securities:
U.S. Government and Government Agency Obligations	$10,411,431,678	$--	$10,411,431,678	$--
Money Market Funds	83,535,058	83,535,058	--	--
Total Investments in Securities:	$10,494,966,736	$83,535,058	$10,411,431,678	$--

See accompanying notes which are an integral part of the financial statements.

Financial Statements

Statement of Assets and Liabilities

		February 28, 2019
Assets
Investment in securities, at value — See accompanying schedule: Unaffiliated issuers (cost $10,571,835,810)	$10,411,431,678
Fidelity Central Funds (cost $83,535,058)	83,535,058
Total Investment in Securities (cost $10,655,370,868)		$10,494,966,736
Receivable for investments sold		55,286,587
Receivable for fund shares sold		36,640,822
Interest receivable		53,843,602
Distributions receivable from Fidelity Central Funds		100,103
Total assets		10,640,837,850
Liabilities
Payable for investments purchased	$173,028,990
Payable for fund shares redeemed	1,338,414
Distributions payable	14
Other payables and accrued expenses	26,552
Total liabilities		174,393,970
Net Assets		$10,466,443,880
Net Assets consist of:
Paid in capital		$10,719,381,536
Total distributable earnings (loss)		(252,937,656)
Net Assets		$10,466,443,880
Net Asset Value and Maximum Offering Price
Net Asset Value, offering price and redemption price per share ($10,466,443,880 ÷ 1,241,267,404 shares)		$8.43

See accompanying notes which are an integral part of the financial statements.

Statement of Operations

		Year ended February 28, 2019
Investment Income
Interest		$246,311,761
Income from Fidelity Central Funds		320,920
Total income		246,632,681
Expenses
Custodian fees and expenses	$85,468
Independent trustees' fees and expenses	34,743
Commitment fees	18,853
Total expenses before reductions	139,064
Expense reductions	(184)
Total expenses after reductions		138,880
Net investment income (loss)		246,493,801
Realized and Unrealized Gain (Loss)
Net realized gain (loss) on:
Investment securities:
Unaffiliated issuers	(86,886,787)
Fidelity Central Funds	(133)
Total net realized gain (loss)		(86,886,920)
Change in net unrealized appreciation (depreciation) on investment securities		73,181,043
Net gain (loss)		(13,705,877)
Net increase (decrease) in net assets resulting from operations		$232,787,924

See accompanying notes which are an integral part of the financial statements.

Statement of Changes in Net Assets

	Year ended February 28, 2019	Year ended February 28, 2018
Increase (Decrease) in Net Assets
Operations
Net investment income (loss)	$246,493,801	$61,831,475
Net realized gain (loss)	(86,886,920)	(7,093,308)
Change in net unrealized appreciation (depreciation)	73,181,043	(230,300,562)
Net increase (decrease) in net assets resulting from operations	232,787,924	(175,562,395)
Distributions to shareholders	(245,404,684)	–
Distributions to shareholders from net investment income	–	(61,251,718)
Total distributions	(245,404,684)	(61,251,718)
Share transactions - net increase (decrease)	6,098,230,924	4,596,064,103
Total increase (decrease) in net assets	6,085,614,164	4,359,249,990
Net Assets
Beginning of period	4,380,829,716	21,579,726
End of period	$10,466,443,880	$4,380,829,716
Other Information
Undistributed net investment income end of period		$523,196

See accompanying notes which are an integral part of the financial statements.

Financial Highlights

Fidelity Series Long-Term Treasury Bond Index Fund

Years ended February 28,	2019	2018	2017 ^A
Selected Per–Share Data
Net asset value, beginning of period	$8.36	$8.59	$10.00
Income from Investment Operations
Net investment income (loss)^B	.248	.241	.119
Net realized and unrealized gain (loss)	.069^C	(.244)	(1.410)
Total from investment operations	.317	(.003)	(1.291)
Distributions from net investment income	(.247)	(.227)	(.119)
Total distributions	(.247)	(.227)	(.119)
Net asset value, end of period	$8.43	$8.36	$8.59
Total Return^D,^E	3.84%	(.12)%	(12.96)%
Ratios to Average Net Assets^F,^G
Expenses before reductions	- %^H	- %^H	.19%^I
Expenses net of fee waivers, if any	- %^H	- %^H	.19%^I
Expenses net of all reductions	- %^H	- %^H	.19%^I
Net investment income (loss)	2.98%	2.76%	2.02%^I
Supplemental Data
Net assets, end of period (000 omitted)	$10,466,444	$4,380,830	$10,734
Portfolio turnover rate^J	23%	15%	45%^I

^A For the period July 7, 2016 (commencement of operations) to February 28, 2017.

^B Calculated based on average shares outstanding during the period.

^C The amount shown for a share outstanding does not correspond with the aggregate net gain (loss) on investments for the period due to the timing of sales and repurchases of shares in relation to fluctuating market values of the investments of the Fund.

^D Total returns for periods of less than one year are not annualized.

^E Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

^F Fees and expenses of any underlying Fidelity Central Funds are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of the expenses of any underlying Fidelity Central Funds.

^G Expense ratios reflect operating expenses of the Fund. Expenses before reductions do not reflect amounts reimbursed by the investment adviser or reductions from expense offset arrangements and do not represent the amount paid by the Fund during periods when reimbursements or reductions occur. Expense ratios before reductions for start-up periods may not be representative of longer-term operating periods. Expenses net of fee waivers reflect expenses after reimbursement by the investment adviser but prior to reductions from expense offset arrangements. Expenses net of all reductions represent the net expenses paid by the Fund.

^H Amount represents less than .005%.

^I Annualized

^J Amount does not include the portfolio activity of any underlying Fidelity Central Funds.

See accompanying notes which are an integral part of the financial statements.

Notes to Financial Statements

For the period ended February 28, 2019

1. Organization.

Fidelity Series Long-Term Treasury Bond Index Fund (the Fund) is a fund of Fidelity Salem Street Trust (the Trust) and is authorized to issue an unlimited number of shares. Shares are offered only to certain other Fidelity funds advised by Fidelity Management & Research Company (FMR) or its affiliates. The Trust is registered under the Investment Company Act of 1940, as amended (the 1940 Act), as an open-end management investment company organized as a Massachusetts business trust.

Effective August 28, 2017, the Fund no longer offered Class F, and all outstanding shares of Class F were exchanged for shares of Series Long-Term Treasury Bond Index.

2. Investments in Fidelity Central Funds.

3. Significant Accounting Policies.

The Fund categorizes the inputs to valuation techniques used to value its investments into a disclosure hierarchy consisting of three levels as shown below:

Level 1 – quoted prices in active markets for identical investments
Level 2 – other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, etc.)
Level 3 – unobservable inputs (including the Fund's own assumptions based on the best information available)

Valuation techniques used to value the Fund's investments by major category are as follows:

Investments in open-end mutual funds, including the Fidelity Central Funds, are valued at their closing net asset value (NAV) each business day and are categorized as Level 1 in the hierarchy.

Book-tax differences are primarily due to market discount, capital loss carryforwards and losses deferred due to wash sales.

As of period end, the cost and unrealized appreciation (depreciation) in securities, and derivatives if applicable, for federal income tax purposes were as follows:

Gross unrealized appreciation	$33,192,548
Gross unrealized depreciation	(215,332,827)
Net unrealized appreciation (depreciation)	$(182,140,279)
Tax Cost	$10,677,107,015

The tax-based components of distributable earnings as of period end were as follows:

Capital loss carryforward	$(67,757,636)
Net unrealized appreciation (depreciation) on securities and other investments	$(182,140,279)

No expiration
Short-term	$(32,781,625)
Long-term	(34,976,011)
Total capital loss carryforward	$(67,757,636)

The tax character of distributions paid was as follows:

	February 28, 2019	February 28, 2018
Ordinary Income	$245,404,684	$ 61,251,718
Total	$245,404,684	$ 61,251,718

Financial Statement	Current Line-Item Presentation (As Applicable)	Prior Line-Item Presentation (As Applicable)
Statement of Assets and Liabilities	Total distributable earnings (loss)	Undistributed/Distributions in excess of/Accumulated net investment income (loss) Accumulated/Undistributed net realized gain (loss) Net unrealized appreciation (depreciation)
Statement of Changes in Net Assets	N/A - removed	Undistributed/Distributions in excess of/Accumulated net investment income (loss) end of period
Statement of Changes in Net Assets	Distributions to shareholders	Distributions to shareholders from net investment income Distributions to shareholders from net realized gain
Distributions to Shareholders Note to Financial Statements	Distributions to shareholders	Distributions to shareholders from net investment income Distributions to shareholders from net realized gain

4. Fees and Other Transactions with Affiliates.

Management Fee. Fidelity Management & Research Company (the investment adviser) and its affiliates provide the Fund with investment management related services for which the Fund does not pay a management fee. Under the management contract, the investment adviser or an affiliate pays all ordinary operating expenses of the Fund, except custody fees, fees and expenses of the independent Trustees, and certain miscellaneous expenses such as proxy and shareholder meeting expenses.

Interfund Trades. The Fund may purchase from or sell securities to other Fidelity Funds under procedures adopted by the Board. The procedures have been designed to ensure these interfund trades are executed in accordance with Rule 17a-7 of the 1940 Act. Interfund trades are included within the respective purchases and sales amounts shown in the Purchases and Sales of Investments note.

5. Committed Line of Credit.

The Fund participates with other funds managed by the investment adviser or an affiliate in a $4.25 billion credit facility (the "line of credit") to be utilized for temporary or emergency purposes to fund shareholder redemptions or for other short-term liquidity purposes. The Fund has agreed to pay commitment fees on its pro-rata portion of the line of credit, which amounted to $18,853 and is reflected in Commitment fees on the Statement of Operations. During the period, the Fund did not borrow on this line of credit.

6. Security Lending.

The Fund lends portfolio securities from time to time in order to earn additional income. On the settlement date of the loan, the Fund receives collateral (in the form of U.S. Treasury obligations, letters of credit and/or cash) against the loaned securities and maintains collateral in an amount not less than 100% of the market value of the loaned securities during the period of the loan. The market value of the loaned securities is determined at the close of business of the Fund and any additional required collateral is delivered to the Fund on the next business day. The Fund or borrower may terminate the loan at any time, and if the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, the Fund may apply collateral received from the borrower against the obligation. The Fund may experience delays and costs in recovering the securities loaned. Any cash collateral received is maintained at the Fund's custodian and/or invested in cash equivalents. At period end, there were no security loans outstanding. Security lending income represents the income earned on investing cash collateral, less rebates paid to borrowers, plus any premium payments received for lending certain types of securities. Security lending income is presented in the Statement of Operations as a component of interest income. Total security lending income during the period amounted to $75,402.

7. Expense Reductions.

Through arrangements with the Fund's custodian, credits realized as a result of certain uninvested cash balances were used to reduce the Fund's expenses. During the period, these credits reduced the Fund's custody expenses by $184.

8. Distributions to Shareholders.

Distributions to shareholders of each class were as follows:

	Year ended February 28, 2019	Year ended February 28, 2018
Distributions to shareholders
Series Long-Term Treasury Bond Index	$245,404,684	$–
Total	$245,404,684	$–
From net investment income
Series Long-Term Treasury Bond Index	$–	$56,620,811
Class F	–	4,630,907
Total	$–	$61,251,718

9. Share Transactions.

Transactions for each class of shares were as follows:

	Shares	Shares	Dollars	Dollars
	Year ended February 28, 2019	Year ended February 28, 2018	Year ended February 28, 2019	Year ended February 28, 2018
Series Long-Term Treasury Bond Index
Shares sold	894,509,766	538,137,484	$7,586,388,893	$4,757,364,546
Reinvestment of distributions	29,331,620	6,388,371	245,404,678	55,642,246
Shares redeemed	(206,900,400)	(21,448,694)	(1,733,562,647)	(188,688,022)
Net increase (decrease)	716,940,986	523,077,161	$6,098,230,924	$4,624,318,770
Class F
Shares sold	–	109,166,248	$–	$960,553,376
Reinvestment of distributions	–	311,902	–	2,729,772
Shares redeemed	–	(110,740,298)	–	(991,537,815)
Net increase (decrease)	–	(1,262,148)	$–	$(28,254,667)

10. Other.

At the end of the period, mutual funds managed by the investment adviser or its affiliates were the owners of record of all of the outstanding shares of the Fund.

Report of Independent Registered Public Accounting Firm

To the Board of Trustees of Fidelity Salem Street Trust and Shareholders of Fidelity Series Long-Term Treasury Bond Index Fund:

Opinion on the Financial Statements

We have audited the accompanying statement of assets and liabilities, including the schedule of investments, of Fidelity Series Long-Term Treasury Bond Index Fund (one of the funds constituting Fidelity Salem Street Trust, referred to hereafter as the “Fund”) as of February 28, 2019, the related statement of operations for the year ended February 28, 2019, the statement of changes in net assets for each of the two years in the period ended February 28, 2019, including the related notes, and the financial highlights for each of the periods indicated therein (collectively referred to as the “financial statements”). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Fund as of February 28, 2019, the results of its operations for the year then ended, the changes in its net assets for each of the two years in the period ended February 28, 2019 and the financial highlights for each of the periods indicated therein in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

These financial statements are the responsibility of the Fund’s management. Our responsibility is to express an opinion on the Fund’s financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Fund in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits of these financial statements in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud.

Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. Our procedures included confirmation of securities owned as of February 28, 2019 by correspondence with the custodian and brokers; when replies were not received from brokers, we performed other auditing procedures. We believe that our audits provide a reasonable basis for our opinion.

PricewaterhouseCoopers LLP

Boston, Massachusetts

April 10, 2019

We have served as the auditor of one or more investment companies in the Fidelity group of funds since 1932.

Trustees and Officers

The fund’s Statement of Additional Information (SAI) includes more information about the Trustees. To request a free copy, call Fidelity at 1-800-544-8544.

Interested Trustees*:

Correspondence intended for a Trustee who is an interested person may be sent to Fidelity Investments, 245 Summer Street, Boston, Massachusetts 02210.

Name, Year of Birth; Principal Occupations and Other Relevant Experience+

Jonathan Chiel (1957)

Year of Election or Appointment: 2016

Trustee

Abigail P. Johnson (1961)

Year of Election or Appointment: 2009

Trustee

Chairman of the Board of Trustees

Jennifer Toolin McAuliffe (1959)

Year of Election or Appointment: 2016

Trustee

* Determined to be an “Interested Trustee” by virtue of, among other things, his or her affiliation with the trust or various entities under common control with FMR.

Independent Trustees:

Correspondence intended for an Independent Trustee may be sent to Fidelity Investments, P.O. Box 55235, Boston, Massachusetts 02205-5235.

Name, Year of Birth; Principal Occupations and Other Relevant Experience+

Elizabeth S. Acton (1951)

Year of Election or Appointment: 2013

Trustee

Ann E. Dunwoody (1953)

Year of Election or Appointment: 2018

Trustee

John Engler (1948)

Year of Election or Appointment: 2014

Trustee

Robert F. Gartland (1951)

Year of Election or Appointment: 2010

Trustee

Arthur E. Johnson (1947)

Year of Election or Appointment: 2008

Trustee

Chairman of the Independent Trustees

Michael E. Kenneally (1954)

Year of Election or Appointment: 2009

Trustee

Vice Chairman of the Independent Trustees

Marie L. Knowles (1946)

Year of Election or Appointment: 2001

Trustee

Mark A. Murray (1954)

Year of Election or Appointment: 2016

Trustee

Advisory Board Members and Officers:

Correspondence intended for an officer may be sent to Fidelity Investments, 245 Summer Street, Boston, Massachusetts 02210. Officers appear below in alphabetical order.

Name, Year of Birth; Principal Occupation

Elizabeth Paige Baumann (1968)

Year of Election or Appointment: 2017

Anti-Money Laundering (AML) Officer

Craig S. Brown (1977)

Year of Election or Appointment: 2019

Assistant Treasurer

Mr. Brown also serves as Assistant Treasurer of other funds. Mr. Brown is an employee of Fidelity Investments (2013-present).

John J. Burke III (1964)

Year of Election or Appointment: 2018

Chief Financial Officer

William C. Coffey (1969)

Year of Election or Appointment: 2018

Secretary and Chief Legal Officer (CLO)

Jonathan Davis (1968)

Year of Election or Appointment: 2010

Assistant Treasurer

Adrien E. Deberghes (1967)

Year of Election or Appointment: 2010

Assistant Treasurer

Laura M. Del Prato (1964)

Year of Election or Appointment: 2018

President and Treasurer

Colm A. Hogan (1973)

Year of Election or Appointment: 2016

Assistant Treasurer

Chris Maher (1972)

Year of Election or Appointment: 2013

Assistant Treasurer

John B. McGinty, Jr. (1962)

Year of Election or Appointment: 2016

Chief Compliance Officer

Jason P. Pogorelec (1975)

Year of Election or Appointment: 2015

Assistant Secretary

Nancy D. Prior (1967)

Year of Election or Appointment: 2014

Vice President

Stacie M. Smith (1974)

Year of Election or Appointment: 2013

Assistant Treasurer

Marc L. Spector (1972)

Year of Election or Appointment: 2016

Deputy Treasurer

Jim Wegmann (1979)

Year of Election or Appointment: 2019

Assistant Treasurer

Mr. Wegmann also serves as Assistant Treasurer of other funds. Mr. Wegmann is an employee of Fidelity Investments (2011-present).

Shareholder Expense Example

As a shareholder of the Fund, you incur two types of costs: (1) transaction costs and (2) ongoing costs, including other Fund expenses. This Example is intended to help you understand your ongoing costs (in dollars) of investing in the Fund and to compare these costs with the ongoing costs of investing in other mutual funds.

The Example is based on an investment of $1,000 invested at the beginning of the period and held for the entire period (September 1, 2018 to February 28, 2019).

Actual Expenses

Hypothetical Example for Comparison Purposes

	Annualized Expense Ratio-^A	Beginning Account Value September 1, 2018	Ending Account Value February 28, 2019	Expenses Paid During Period-^B September 1, 2018 to February 28, 2019
Series Long-Term Treasury Bond Index	- %-^C
Actual		$1,000.00	$1,007.80	$--^D
Hypothetical-^E		$1,000.00	$1,024.79	$--^D

^A Annualized expense ratio reflects expenses net of applicable fee waivers.

^B Expenses are equal to the Fund's annualized expense ratio, multiplied by the average account value over the period, multiplied by 181/365 (to reflect the one-half year period).

^C Amount represents less than .005%.

^D Amount represents less than $.005.

^E 5% return per year before expenses

Distributions (Unaudited)

A total of 99.90% of the dividends distributed during the fiscal year was derived from interest on U.S. Government securities which is generally exempt from state income tax.

The fund will notify shareholders in January 2020 of amounts for use in preparing 2019 income tax returns.

Board Approval of Investment Advisory Contracts and Management Fees

Fidelity Series Long-Term Treasury Bond Index Fund

At its September 2018 meeting, the Board unanimously determined to renew the fund's Advisory Contracts. In considering whether to renew the Advisory Contracts for the fund, the Board considered all factors it believed relevant and reached a determination, with the assistance of fund counsel and Independent Trustees' counsel and through the exercise of its business judgment, that the renewal of the Advisory Contracts was in the best interests of the fund and its shareholders and the fact that no fee is payable under the management contract was fair and reasonable.

Administrative Services. The Board considered (i) the nature, extent, quality, and cost of advisory and administrative services performed by the Investment Advisers and their affiliates under the Advisory Contracts and under separate agreements covering transfer agency, pricing and bookkeeping, and securities lending services for the fund; (ii) the nature and extent of the supervision of third party service providers, principally custodians, subcustodians, and pricing vendors; and (iii) the resources devoted to, and the record of compliance with, the fund's compliance policies and procedures.

Investment Performance. The Board considered whether the fund has operated in accordance with its investment objective, as well as its record of compliance with its investment restrictions. The Board reviewed the fund's absolute investment performance, as well as the fund's relative investment performance. In this regard, the Board noted that the fund is designed to offer an investment option for other investment companies managed by Fidelity and ultimately to enhance the performance of those investment companies.

Based on its review, the Board concluded that the nature, extent, and quality of services provided to the fund under the Advisory Contracts should continue to benefit the shareholders of the fund.

The Board considered that the fund does not pay FMR a management fee for investment advisory services. The Board also noted that FMR or an affiliate undertakes to pay all operating expenses of the fund, except transfer agent fees, 12b-1 fees, Independent Trustee fees and expenses, custodian fees and expenses, proxy and shareholder meeting expenses, interest, taxes, brokerage expenses, and extraordinary expenses (such as litigation expenses).

Based on its review, the Board considered that the fund does not pay a management fee and concluded that the total expense ratio of each class of the fund was reasonable in light of the services that the fund and its shareholders receive and the other factors considered.

Costs of the Services and Profitability. The Board considered the level of Fidelity's profits in respect of all the Fidelity funds.

The Board concluded that the costs of the services provided by and the profits realized by Fidelity in connection with the operation of the fund were not relevant to the renewal of the Advisory Contracts because the fund pays no advisory fees and FMR or an affiliate bears all expenses of the fund, with limited exceptions.

Economies of Scale. The Board concluded that because the fund pays no advisory fees and FMR or an affiliate bears all expenses of the fund with certain limited exceptions, the realization of economies of scale was not a material factor in the Board's decision to renew the fund's Advisory Contracts.

Fidelity Investments

XS8-ANN-0419
1.9872674.102

Fidelity® SAI U.S. Treasury Bond Index Fund

Annual Report

February 28, 2019

Account Type	Website	Phone Number
Brokerage, Mutual Fund, or Annuity Contracts:	fidelity.com/mailpreferences	1-800-343-3548
Employer Provided Retirement Accounts:	netbenefits.fidelity.com/preferences (choose 'no' under Required Disclosures to continue to print)	1-800-343-0860
Advisor Sold Accounts Serviced Through Your Financial Intermediary:	Contact Your Financial Intermediary	Your Financial Intermediary's phone number
Advisor Sold Accounts Serviced by Fidelity:	institutional.fidelity.com	1-877-208-0098

Contents

Performance
Management's Discussion of Fund Performance
Investment Summary
Schedule of Investments
Financial Statements
Notes to Financial Statements
Report of Independent Registered Public Accounting Firm
Trustees and Officers
Shareholder Expense Example
Distributions
Board Approval of Investment Advisory Contracts and Management Fees

You may also call 1-800-544-3455 to request a free copy of the proxy voting guidelines.

Standard & Poor's, S&P and S&P 500 are registered service marks of The McGraw-Hill Companies, Inc. and have been licensed for use by Fidelity Distributors Corporation.

Other third-party marks appearing herein are the property of their respective owners.

NOT FDIC INSURED •MAY LOSE VALUE •NO BANK GUARANTEE

Neither the Fund nor Fidelity Distributors Corporation is a bank.

Performance: The Bottom Line

Average Annual Total Returns

For the periods ended February 28, 2019	Past 1 year	Life of fund^A
Fidelity® SAI US. Treasury Bond Index Fund	3.23%	0.57%

^A From March 1, 2016

$10,000 Over Life of Fund

Let's say hypothetically that $10,000 was invested in Fidelity® SAI U.S. Treasury Bond Index Fund on March 1, 2016, when the fund started.

The chart shows how the value of your investment would have changed, and also shows how the Bloomberg Barclays U.S. Treasury Index performed over the same period.

	Period Ending Values
	$10,171	Fidelity® SAI US. Treasury Bond Index Fund
	$10,194	Bloomberg Barclays U.S. Treasury Index

Management's Discussion of Fund Performance

Comments from Co-Portfolio Managers Brandon Bettencourt and Jay Small: For the fiscal year, the fund gained 3.23%, matching, net of fees, the 3.23% advance of the benchmark Bloomberg Barclays 1-30 Year Treasury Bond Index. This result met our goal of producing monthly returns, before expenses, that closely match the benchmark’s returns. We use a method known as stratified sampling, which matches the index’s risk factors, but does not always hold all bonds in the exact proportions of the index. From March through November 2018, U.S. Treasuries were under pressure due to rising interest rates and expectations for further policy rate increases by the Federal Reserve. Another factor weighing on U.S. Treasuries was the Fed’s decision to begin reducing the $4.5 trillion in government securities it accumulated as part of the quantitative easing program it deployed to battle the recession and financial crisis a decade ago. That said, from December through period end, U.S. Treasury prices rallied strongly after the Fed made a dovish pivot, indicating that the case for raising interest rates had weakened somewhat with slowing global economic growth and muted inflation. Moreover, the Fed communicated that it would be patient in assessing the need for further interest rate hikes. Against this backdrop, the yield curve flattened and both intermediate- and long-term U.S. Treasuries outperformed their shorter-term counterparts.

Investment Summary (Unaudited)

Coupon Distribution as of February 28, 2019

	% of fund's investments
1 - 1.99%	21.9
2 - 2.99%	58.9
3 - 3.99%	12.7
4 - 4.99%	2.7
5 - 5.99%	1.5
6 - 6.99%	0.3
7 - 7.99%	0.8
8 - 8.99%	0.0

Coupon distribution shows the range of stated interest rates on the fund's investments, excluding short-term investments.

Asset Allocation (% of fund's net assets)

As of February 28, 2019
	U.S. Treasury Obligations	99.0%
	Short-Term Investments and Net Other Assets (Liabilities)	1.0%

Percentages shown as 0.0% may reflect amounts less than 0.05%.

Schedule of Investments February 28, 2019

Showing Percentage of Net Assets

U.S. Government and Government Agency Obligations - 99.0%
	Principal Amount	Value
U.S. Treasury Obligations - 99.0%
U.S. Treasury Bonds:
2.25% 8/15/46	$10,180,000	$8,593,749
2.5% 2/15/45	14,953,000	13,384,687
2.5% 2/15/46	8,790,000	7,838,208
2.5% 5/15/46	18,946,000	16,881,922
2.75% 8/15/42	2,303,000	2,181,823
2.75% 11/15/42	2,231,000	2,110,909
2.75% 8/15/47	11,621,000	10,871,536
2.75% 11/15/47	3,296,000	3,081,116
2.875% 5/15/43	4,806,000	4,639,480
2.875% 8/15/45	7,467,000	7,186,404
2.875% 11/15/46	13,392,000	12,872,537
3% 5/15/42	8,638,000	8,555,669
3% 11/15/44	14,885,000	14,668,702
3% 5/15/45	15,841,000	15,616,380
3% 11/15/45	26,751,000	26,364,365
3% 2/15/47	14,024,000	13,820,762
3% 5/15/47	12,159,000	11,967,116
3% 2/15/48	5,445,000	5,350,138
3% 8/15/48	21,322,000	20,954,695
3% 2/15/49	8,506,000	8,364,455
3.125% 2/15/42	5,987,000	6,063,241
3.125% 2/15/43	2,602,000	2,626,394
3.125% 8/15/44	17,031,000	17,160,063
3.125% 5/15/48	17,850,000	17,973,416
3.375% 5/15/44	50,823,000	53,451,502
3.375% 11/15/48	29,358,000	31,036,911
3.625% 2/15/44	18,685,000	20,470,293
3.75% 8/15/41	8,847,000	9,880,993
3.75% 11/15/43	1,282,000	1,432,034
3.875% 8/15/40	15,178,000	17,276,833
4.25% 5/15/39	122,000	146,214
4.25% 11/15/40	3,863,000	4,627,451
4.375% 2/15/38	161,000	196,049
4.375% 11/15/39	1,431,000	1,742,410
4.375% 5/15/40	7,791,000	9,487,369
4.375% 5/15/41	25,884,000	31,565,336
4.5% 5/15/38	7,016,000	8,682,300
4.5% 8/15/39	3,618,000	4,477,699
4.625% 2/15/40	8,917,000	11,213,824
4.75% 2/15/37	13,000	16,465
4.75% 2/15/41	4,036,000	5,166,238
5% 5/15/37	2,667,000	3,479,393
5.25% 11/15/28	19,906,000	24,165,573
5.25% 2/15/29	9,219,000	11,232,775
5.375% 2/15/31	817,000	1,033,186
5.5% 8/15/28	2,865,000	3,525,629
6% 2/15/26	3,771,000	4,574,989
6.125% 11/15/27	3,054,000	3,861,282
6.125% 8/15/29	244,000	318,887
6.25% 8/15/23	77,000	88,962
6.25% 5/15/30	63,000	84,122
6.5% 11/15/26	39,000	49,420
6.625% 2/15/27	50,000	64,178
6.75% 8/15/26	23,000	29,382
6.875% 8/15/25	8,000	10,016
7.125% 2/15/23	1,275,000	1,494,041
7.25% 8/15/22	38,000	43,891
7.5% 11/15/24	15,867,000	19,989,941
7.625% 11/15/22	50,000	58,963
7.625% 2/15/25	79,000	100,818
7.875% 2/15/21	246,000	270,908
8% 11/15/21	17,000	19,419
8.125% 5/15/21	245,000	274,132
8.125% 8/15/21	96,000	108,679
8.75% 5/15/20	38,000	40,782
8.75% 8/15/20	216,000	234,951
U.S. Treasury Notes:
1.125% 2/28/21	2,376,000	2,310,938
1.125% 6/30/21	24,554,000	23,794,361
1.125% 7/31/21	11,347,000	10,979,109
1.125% 8/31/21	9,563,000	9,242,490
1.125% 9/30/21	5,008,000	4,837,415
1.25% 3/31/21	9,048,000	8,818,266
1.25% 10/31/21	9,937,000	9,615,600
1.25% 7/31/23	5,561,000	5,266,006
1.375% 3/31/20	12,399,000	12,243,044
1.375% 4/30/20	11,238,000	11,086,989
1.375% 8/31/20	12,963,000	12,739,186
1.375% 9/15/20	11,463,000	11,259,263
1.375% 9/30/20	977,000	958,987
1.375% 10/31/20	19,903,000	19,518,934
1.375% 1/31/21	13,561,000	13,264,353
1.375% 4/30/21	1,812,000	1,768,328
1.375% 5/31/21	572,000	557,722
1.375% 6/30/23	26,693,000	25,439,680
1.375% 8/31/23	1,103,000	1,049,272
1.375% 9/30/23	6,179,000	5,872,222
1.5% 4/15/20	9,067,000	8,962,871
1.5% 5/31/20	10,599,000	10,461,544
1.5% 6/15/20	18,748,000	18,496,074
1.5% 7/15/20	11,000,000	10,842,305
1.5% 8/15/20	11,224,000	11,054,325
1.5% 1/31/22	69,000	67,073
1.5% 2/28/23	4,873,000	4,684,742
1.5% 3/31/23	1,539,000	1,478,342
1.5% 8/15/26	20,405,000	18,829,989
1.625% 3/15/20	17,554,000	17,386,688
1.625% 6/30/20	15,694,000	15,499,664
1.625% 7/31/20	22,298,000	22,007,081
1.625% 10/15/20	11,639,000	11,465,779
1.625% 11/30/20	13,489,000	13,275,073
1.625% 8/15/22	40,000	38,825
1.625% 8/31/22	15,416,000	14,960,144
1.625% 11/15/22	254,000	246,023
1.625% 4/30/23	2,979,000	2,873,920
1.625% 5/31/23	2,562,000	2,469,628
1.625% 10/31/23	144,000	138,313
1.625% 2/15/26	5,181,000	4,850,914
1.625% 5/15/26	25,238,000	23,571,898
1.75% 10/31/20	357,000	352,273
1.75% 11/15/20	3,981,000	3,927,816
1.75% 12/31/20	23,325,000	22,991,525
1.75% 11/30/21	9,531,000	9,340,380
1.75% 2/28/22	10,224,000	10,003,545
1.75% 3/31/22	517,000	505,590
1.75% 4/30/22	2,435,000	2,379,927
1.75% 5/15/22	40,000	39,069
1.75% 5/31/22	18,289,000	17,859,637
1.75% 6/30/22	26,870,000	26,230,788
1.75% 9/30/22	385,000	374,984
1.75% 1/31/23	175,000	169,989
1.75% 5/15/23	287,000	278,155
1.875% 12/15/20	11,305,000	11,171,636
1.875% 11/30/21	482,000	474,036
1.875% 1/31/22	17,135,000	16,831,121
1.875% 2/28/22	5,216,000	5,121,460
1.875% 3/31/22	22,568,000	22,158,073
1.875% 4/30/22	23,980,000	23,525,691
1.875% 5/31/22	6,821,000	6,687,244
1.875% 7/31/22	9,867,000	9,663,493
1.875% 8/31/22	6,473,000	6,335,702
1.875% 9/30/22	18,600,000	18,197,484
1.875% 10/31/22	17,759,000	17,362,197
2% 1/15/21	13,591,000	13,455,090
2% 2/28/21	48,000	47,496
2% 10/31/21	242,000	238,843
2% 11/15/21	147,000	145,111
2% 12/31/21	18,057,000	17,813,654
2% 2/15/22	210,000	207,055
2% 7/31/22	49,716,000	48,888,695
2% 10/31/22	12,029,000	11,812,384
2% 11/30/22	56,743,000	55,694,585
2% 2/15/23	8,751,000	8,580,082
2% 4/30/24	2,462,000	2,397,180
2% 5/31/24	15,708,000	15,286,461
2% 6/30/24	23,075,000	22,436,832
2% 2/15/25	10,083,000	9,752,939
2% 8/15/25	44,227,000	42,628,954
2% 11/15/26	12,589,000	12,017,086
2.125% 8/31/20	218,000	216,578
2.125% 1/31/21	4,398,000	4,363,641
2.125% 9/30/21	30,000	29,711
2.125% 12/31/21	275,000	272,164
2.125% 6/30/22	8,062,000	7,965,004
2.125% 12/31/22	19,557,000	19,277,396
2.125% 11/30/23	2,629,000	2,581,452
2.125% 2/29/24	3,213,000	3,150,748
2.125% 3/31/24	14,484,000	14,196,583
2.125% 7/31/24	20,395,000	19,945,673
2.125% 9/30/24	18,290,000	17,868,473
2.125% 11/30/24	13,904,000	13,568,892
2.125% 5/15/25	6,411,000	6,235,950
2.25% 2/15/21	16,284,000	16,193,675
2.25% 3/31/21	434,000	431,508
2.25% 7/31/21	18,365,000	18,253,806
2.25% 1/31/24	7,160,000	7,065,186
2.25% 11/15/24	49,622,000	48,759,430
2.25% 12/31/24	6,055,000	5,946,672
2.25% 11/15/25	22,880,000	22,358,050
2.25% 2/15/27	20,179,000	19,583,877
2.25% 8/15/27	61,981,000	59,954,504
2.25% 11/15/27	18,745,000	18,097,712
2.375% 4/30/20	1,000	998
2.375% 3/15/21	19,006,000	18,945,864
2.375% 4/15/21	17,001,000	16,947,872
2.375% 1/31/23	12,947,000	12,877,713
2.375% 8/15/24	3,028,000	2,998,666
2.375% 5/15/27	23,270,000	22,770,058
2.5% 5/31/20	24,746,000	24,726,667
2.5% 6/30/20	1,341,000	1,339,900
2.5% 12/31/20	39,725,000	39,689,309
2.5% 1/31/21	7,966,000	7,961,332
2.5% 1/15/22	20,027,000	20,023,871
2.5% 3/31/23	13,117,000	13,106,752
2.5% 8/15/23	36,925,000	36,888,941
2.5% 1/31/24	30,433,000	30,399,714
2.5% 5/15/24	7,959,000	7,939,103
2.5% 1/31/25	5,697,000	5,670,518
2.625% 8/31/20	51,349,000	51,395,134
2.625% 11/15/20	380,000	380,401
2.625% 5/15/21	36,658,000	36,733,893
2.625% 6/15/21	12,469,000	12,499,685
2.625% 7/15/21	8,534,000	8,555,335
2.625% 12/15/21	27,012,000	27,102,744
2.625% 2/28/23	8,875,000	8,910,015
2.625% 6/30/23	16,952,000	17,021,530
2.625% 12/31/23	53,354,000	53,574,919
2.625% 3/31/25	16,295,000	16,323,007
2.625% 12/31/25	26,820,000	26,835,715
2.75% 9/30/20	51,683,000	51,830,377
2.75% 11/30/20	33,631,000	33,741,352
2.75% 8/15/21	29,533,000	29,697,970
2.75% 9/15/21	15,883,000	15,976,685
2.75% 5/31/23	15,845,000	15,988,595
2.75% 7/31/23	18,682,000	18,855,684
2.75% 8/31/23	17,297,000	17,465,240
2.75% 11/15/23	566,000	571,505
2.75% 2/15/24	1,132,000	1,143,276
2.75% 2/28/25	5,528,000	5,577,666
2.75% 6/30/25	9,260,000	9,338,493
2.75% 8/31/25	6,622,000	6,676,062
2.75% 2/15/28	1,969,000	1,976,384
2.875% 10/31/20	52,018,000	52,282,154
2.875% 10/15/21	51,169,000	51,634,718
2.875% 11/15/21	14,182,000	14,315,510
2.875% 9/30/23	30,644,000	31,097,675
2.875% 10/31/23	24,082,000	24,443,230
2.875% 11/30/23	17,750,000	18,029,424
2.875% 4/30/25	2,976,000	3,022,849
2.875% 5/31/25	5,889,000	5,981,246
2.875% 7/31/25	33,135,000	33,657,912
2.875% 11/30/25	6,413,000	6,513,704
2.875% 5/15/28	37,179,000	37,678,593
2.875% 8/15/28	23,308,000	23,610,276
3% 9/30/25	7,460,000	7,633,387
3% 10/31/25	47,562,000	48,671,161
3.125% 5/15/21	357,000	361,546
3.125% 11/15/28	8,525,000	8,816,049
3.5% 5/15/20	408,000	412,478
3.625% 2/15/21	517,000	527,704
		2,868,284,895
TOTAL U.S. GOVERNMENT AND GOVERNMENT AGENCY OBLIGATIONS
(Cost $2,875,036,528)		2,868,284,895
	Shares	Value

Money Market Funds - 1.2%
Fidelity Cash Central Fund, 2.44% (a)
(Cost $34,822,361)	34,815,397	34,822,361
TOTAL INVESTMENT IN SECURITIES - 100.2%
(Cost $2,909,858,889)		2,903,107,256
NET OTHER ASSETS (LIABILITIES) - (0.2)%		(5,568,880)
NET ASSETS - 100%		$2,897,538,376

Legend

Affiliated Central Funds

Information regarding fiscal year to date income earned by the Fund from investments in Fidelity Central Funds is as follows:

Fund	Income earned
Fidelity Cash Central Fund	$340,453
Total	$340,453

Investment Valuation

	Valuation Inputs at Reporting Date:
Description	Total	Level 1	Level 2	Level 3
Investments in Securities:
U.S. Government and Government Agency Obligations	$2,868,284,895	$--	$2,868,284,895	$--
Money Market Funds	34,822,361	34,822,361	--	--
Total Investments in Securities:	$2,903,107,256	$34,822,361	$2,868,284,895	$--

See accompanying notes which are an integral part of the financial statements.

Financial Statements

Statement of Assets and Liabilities

		February 28, 2019
Assets
Investment in securities, at value — See accompanying schedule: Unaffiliated issuers (cost $2,875,036,528)	$2,868,284,895
Fidelity Central Funds (cost $34,822,361)	34,822,361
Total Investment in Securities (cost $2,909,858,889)		$2,903,107,256
Receivable for investments sold		28,407,440
Receivable for fund shares sold		2,897,433
Interest receivable		14,675,773
Distributions receivable from Fidelity Central Funds		53,524
Prepaid expenses		1,850
Receivable from investment adviser for expense reductions		365,076
Total assets		2,949,508,352
Liabilities
Payable for investments purchased	$49,228,319
Payable for fund shares redeemed	417,368
Distributions payable	1,726,005
Accrued management fee	95,552
Other affiliated payables	220,717
Other payables and accrued expenses	282,015
Total liabilities		51,969,976
Net Assets		$2,897,538,376
Net Assets consist of:
Paid in capital		$2,917,472,509
Total distributable earnings (loss)		(19,934,133)
Net Assets, for 300,230,343 shares outstanding		$2,897,538,376
Net Asset Value, offering price and redemption price per share ($2,897,538,376 ÷ 300,230,343 shares)		$9.65

See accompanying notes which are an integral part of the financial statements.

Statement of Operations

		Year ended February 28, 2019
Investment Income
Interest		$52,442,209
Income from Fidelity Central Funds		340,453
Total income		52,782,662
Expenses
Management fee	$854,905
Transfer agent fees	1,602,947
Accounting fees and expenses	384,913
Custodian fees and expenses	24,983
Independent trustees' fees and expenses	9,032
Registration fees	317,919
Audit	61,039
Legal	2,058
Miscellaneous	9,881
Total expenses before reductions	3,267,677
Expense reductions	(2,614,597)
Total expenses after reductions		653,080
Net investment income (loss)		52,129,582
Realized and Unrealized Gain (Loss)
Net realized gain (loss) on:
Investment securities:
Unaffiliated issuers	(6,989,514)
Fidelity Central Funds	(318)
Total net realized gain (loss)		(6,989,832)
Change in net unrealized appreciation (depreciation) on:
Investment securities:
Unaffiliated issuers	19,647,539
Fidelity Central Funds	(1)
Total change in net unrealized appreciation (depreciation)		19,647,538
Net gain (loss)		12,657,706
Net increase (decrease) in net assets resulting from operations		$64,787,288

See accompanying notes which are an integral part of the financial statements.

Statement of Changes in Net Assets

	Year ended February 28, 2019	Year ended February 28, 2018
Increase (Decrease) in Net Assets
Operations
Net investment income (loss)	$52,129,582	$13,602,340
Net realized gain (loss)	(6,989,832)	(13,032,917)
Change in net unrealized appreciation (depreciation)	19,647,538	(26,133,559)
Net increase (decrease) in net assets resulting from operations	64,787,288	(25,564,136)
Distributions to shareholders	(46,208,305)	–
Distributions to shareholders from net investment income	–	(12,551,455)
Total distributions	(46,208,305)	(12,551,455)
Share transactions
Proceeds from sales of shares	3,187,231,913	1,850,540,447
Reinvestment of distributions	29,502,481	10,680,954
Cost of shares redeemed	(1,418,818,781)	(772,797,110)
Net increase (decrease) in net assets resulting from share transactions	1,797,915,613	1,088,424,291
Total increase (decrease) in net assets	1,816,494,596	1,050,308,700
Net Assets
Beginning of period	1,081,043,780	30,735,080
End of period	$2,897,538,376	$1,081,043,780
Other Information
Undistributed net investment income end of period		$556,981
Shares
Sold	332,203,725	189,246,399
Issued in reinvestment of distributions	3,084,223	1,098,110
Redeemed	(148,216,607)	(80,330,835)
Net increase (decrease)	187,071,341	110,013,674

See accompanying notes which are an integral part of the financial statements.

Financial Highlights

Fidelity SAI U.S. Treasury Bond Index Fund


Years ended February 28,	2019	2018	2017 ^A
Selected Per–Share Data
Net asset value, beginning of period	$9.55	$9.77	$10.00
Income from Investment Operations
Net investment income (loss)^B	.233	.192	.146
Net realized and unrealized gain (loss)	.072	(.247)	(.234)
Total from investment operations	.305	(.055)	(.088)
Distributions from net investment income	(.205)	(.165)	(.133)
Distributions from net realized gain	–	–	(.009)
Total distributions	(.205)	(.165)	(.142)
Net asset value, end of period	$9.65	$9.55	$9.77
Total Return^C	3.23%	(.59)%	(.90)%
Ratios to Average Net Assets^D,^E
Expenses before reductions	.15%	.16%	.41%
Expenses net of fee waivers, if any	.03%	.04%	.10%
Expenses net of all reductions	.03%	.04%	.10%
Net investment income (loss)	2.45%	1.95%	1.46%
Supplemental Data
Net assets, end of period (000 omitted)	$2,897,538	$1,081,044	$30,735
Portfolio turnover rate^F	73%	144%	511%

^A For the period March 1, 2016 (commencement of operations) to February 28, 2017.

^B Calculated based on average shares outstanding during the period.

^C Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

^D Fees and expenses of any underlying Fidelity Central Funds are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of the expenses of any underlying Fidelity Central Funds.

^E Expense ratios reflect operating expenses of the Fund. Expenses before reductions do not reflect amounts reimbursed by the investment adviser or reductions from expense offset arrangements and do not represent the amount paid by the Fund during periods when reimbursements or reductions occur. Expense ratios before reductions for start-up periods may not be representative of longer term operating periods. Expenses net of fee waivers reflect expenses after reimbursement by the investment adviser but prior to reductions from expense offset arrangements. Expenses net of all reductions represent the net expenses paid by the Fund.

^F Amount does not include the portfolio activity of any underlying Fidelity Central Funds.

See accompanying notes which are an integral part of the financial statements.

Notes to Financial Statements

For the period ended February 28, 2019

1. Organization.

Fidelity SAI U.S. Treasury Bond Index Fund (the Fund) is a fund of Fidelity Salem Street Trust (the Trust) and is authorized to issue an unlimited number of shares. Shares are offered exclusively to certain clients of Fidelity Management & Research Company (FMR) or its affiliates. The Trust is registered under the Investment Company Act of 1940, as amended (the 1940 Act), as an open-end management investment company organized as a Massachusetts business trust.

2. Investments in Fidelity Central Funds.

3. Significant Accounting Policies.

The Fund categorizes the inputs to valuation techniques used to value its investments into a disclosure hierarchy consisting of three levels as shown below:

Level 1 – quoted prices in active markets for identical investments
Level 2 – other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, etc.)
Level 3 – unobservable inputs (including the Fund's own assumptions based on the best information available)

Valuation techniques used to value the Fund's investments by major category are as follows:

Investments in open-end mutual funds, including the Fidelity Central Funds, are valued at their closing net asset value (NAV) each business day and are categorized as Level 1 in the hierarchy.

Book-tax differences are primarily due to market discount, capital loss carryforwards and losses deferred due to wash sales and excise tax regulations.

As of period end, the cost and unrealized appreciation (depreciation) in securities, and derivatives if applicable, for federal income tax purposes were as follows:

Gross unrealized appreciation	$11,643,429
Gross unrealized depreciation	(14,976,152)
Net unrealized appreciation (depreciation)	$(3,332,723)
Tax Cost	$2,906,439,979

The tax-based components of distributable earnings as of period end were as follows:

Undistributed ordinary income	$441,008
Capital loss carryforward	$(17,042,418)
Net unrealized appreciation (depreciation) on securities and other investments	$(3,332,723)

No expiration
Short-term	$(13,916,071)
Long-term	(3,126,347)
Total capital loss carryforward	$(17,042,418)

The tax character of distributions paid was as follows:

	February 28, 2019	February 28, 2018
Ordinary Income	$46,208,305	$ 12,551,455

Financial Statement	Current Line-Item Presentation (As Applicable)	Prior Line-Item Presentation (As Applicable)
Statement of Assets and Liabilities	Total distributable earnings (loss)	Undistributed/Distributions in excess of/Accumulated net investment income (loss) Accumulated/Undistributed net realized gain (loss) Net unrealized appreciation (depreciation)
Statement of Changes in Net Assets	N/A - removed	Undistributed/Distributions in excess of/Accumulated net investment income (loss) end of period
Statement of Changes in Net Assets	Distributions to shareholders	Distributions to shareholders from net investment income Distributions to shareholders from net realized gain

4. Fees and Other Transactions with Affiliates.

Accounting Fees. Fidelity Service Company, Inc. (FSC, an affiliate of the investment adviser, maintains the Fund's accounting records. The fee is based on the level of average net assets for each month. For the period, the fees were equivalent to an annual rate of .02%.

5. Committed Line of Credit.

The Fund participates with other funds managed by the investment adviser or an affiliate in a $4.25 billion credit facility (the "line of credit") to be utilized for temporary or emergency purposes to fund shareholder redemptions or for other short-term liquidity purposes. The Fund has agreed to pay commitment fees on its pro-rata portion of the line of credit, which amounted to $5,250 and is reflected in Miscellaneous expenses on the Statement of Operations. During the period, the Fund did not borrow on this line of credit.

6. Expense Reductions.

7. Other.

At the end of the period, Strategic Advisers Core Income Fund and Strategic Advisers Fidelity Core Income Fund were the owners of record of approximately 44% and 21%, respectively of the total outstanding shares of the Fund.

Report of Independent Registered Public Accounting Firm

To the Trustees of Fidelity Salem Street Trust and Shareholders of Fidelity SAI U.S. Treasury Bond Index Fund:

Opinion on the Financial Statements and Financial Highlights

We have audited the accompanying statement of assets and liabilities of Fidelity SAI U.S. Treasury Bond Index Fund (the "Fund"), a fund of Fidelity Salem Street Trust, including the schedule of investments, as of February 28, 2019, the related statement of operations for the year then ended, the statement of changes in net assets for each of the two years in the period then ended, the financial highlights for each of the two years in the period then ended and for the period from March 1, 2016 (commencement of operations) to February 28, 2017, and the related notes. In our opinion, the financial statements and financial highlights present fairly, in all material respects, the financial position of the Fund as of February 28, 2019, and the results of its operations for the year then ended, the changes in its net assets for each of the two years in the period then ended, and the financial highlights for each of the two years in the period then ended and for the period from March 1, 2016 (commencement of operations) to February 28, 2017, in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

/s/ Deloitte & Touche LLP

Boston, Massachusetts

April 11, 2019

We have served as the auditor of one or more of the Fidelity investment companies since 1999.

Trustees and Officers

The fund’s Statement of Additional Information (SAI) includes more information about the Trustees. To request a free copy, call Fidelity at 1-800-544-3455.

Interested Trustees*:

Correspondence intended for a Trustee who is an interested person may be sent to Fidelity Investments, 245 Summer Street, Boston, Massachusetts 02210.

Name, Year of Birth; Principal Occupations and Other Relevant Experience+

Jonathan Chiel (1957)

Year of Election or Appointment: 2016

Trustee

Abigail P. Johnson (1961)

Year of Election or Appointment: 2009

Trustee

Chairman of the Board of Trustees

Jennifer Toolin McAuliffe (1959)

Year of Election or Appointment: 2016

Trustee

* Determined to be an “Interested Trustee” by virtue of, among other things, his or her affiliation with the trust or various entities under common control with FMR.

Independent Trustees:

Correspondence intended for an Independent Trustee may be sent to Fidelity Investments, P.O. Box 55235, Boston, Massachusetts 02205-5235.

Name, Year of Birth; Principal Occupations and Other Relevant Experience+

Elizabeth S. Acton (1951)

Year of Election or Appointment: 2013

Trustee

Ann E. Dunwoody (1953)

Year of Election or Appointment: 2018

Trustee

John Engler (1948)

Year of Election or Appointment: 2014

Trustee

Robert F. Gartland (1951)

Year of Election or Appointment: 2010

Trustee

Arthur E. Johnson (1947)

Year of Election or Appointment: 2008

Trustee

Chairman of the Independent Trustees

Michael E. Kenneally (1954)

Year of Election or Appointment: 2009

Trustee

Vice Chairman of the Independent Trustees

Marie L. Knowles (1946)

Year of Election or Appointment: 2001

Trustee

Mark A. Murray (1954)

Year of Election or Appointment: 2016

Trustee

Advisory Board Members and Officers:

Correspondence intended for an officer may be sent to Fidelity Investments, 245 Summer Street, Boston, Massachusetts 02210. Officers appear below in alphabetical order.

Name, Year of Birth; Principal Occupation

Elizabeth Paige Baumann (1968)

Year of Election or Appointment: 2017

Anti-Money Laundering (AML) Officer

Craig S. Brown (1977)

Year of Election or Appointment: 2019

Assistant Treasurer

Mr. Brown also serves as Assistant Treasurer of other funds. Mr. Brown is an employee of Fidelity Investments (2013-present).

John J. Burke III (1964)

Year of Election or Appointment: 2018

Chief Financial Officer

William C. Coffey (1969)

Year of Election or Appointment: 2018

Secretary and Chief Legal Officer (CLO)

Jonathan Davis (1968)

Year of Election or Appointment: 2010

Assistant Treasurer

Adrien E. Deberghes (1967)

Year of Election or Appointment: 2010

Assistant Treasurer

Laura M. Del Prato (1964)

Year of Election or Appointment: 2018

President and Treasurer

Colm A. Hogan (1973)

Year of Election or Appointment: 2016

Assistant Treasurer

Chris Maher (1972)

Year of Election or Appointment: 2013

Assistant Treasurer

John B. McGinty, Jr. (1962)

Year of Election or Appointment: 2016

Chief Compliance Officer

Jason P. Pogorelec (1975)

Year of Election or Appointment: 2015

Assistant Secretary

Nancy D. Prior (1967)

Year of Election or Appointment: 2014

Vice President

Stacie M. Smith (1974)

Year of Election or Appointment: 2013

Assistant Treasurer

Marc L. Spector (1972)

Year of Election or Appointment: 2016

Deputy Treasurer

Jim Wegmann (1979)

Year of Election or Appointment: 2019

Assistant Treasurer

Mr. Wegmann also serves as Assistant Treasurer of other funds. Mr. Wegmann is an employee of Fidelity Investments (2011-present).

Shareholder Expense Example

As a shareholder of the Fund, you incur two types of costs: (1) transaction costs, and (2) ongoing costs, including other Fund expenses. This Example is intended to help you understand your ongoing costs (in dollars) of investing in the Fund and to compare these costs with the ongoing costs of investing in other mutual funds.

The Example is based on an investment of $1,000 invested at the beginning of the period and held for the entire period (September 1, 2018 to February 28, 2019).

Actual Expenses

Hypothetical Example for Comparison Purposes

	Annualized Expense Ratio-^A	Beginning Account Value September 1, 2018	Ending Account Value February 28, 2019	Expenses Paid During Period-^B September 1, 2018 to February 28, 2019
Actual	.03%	$1,000.00	$1,018.70	$.15
Hypothetical-^C		$1,000.00	$1,024.65	$.15

^A Annualized expense ratio reflects expenses net of applicable fee waivers.

^B Expenses are equal to the Fund's annualized expense ratio, multiplied by the average account value over the period, multiplied by 181/365 (to reflect the one-half year period).

^C 5% return per year before expenses

Distributions (Unaudited)

A total of 99.58% of the dividends distributed during the fiscal year was derived from interest on U.S. Government securities which is generally exempt from state income tax.

The fund will notify shareholders in January 2020 of amounts for use in preparing 2019 income tax returns.

Board Approval of Investment Advisory Contracts and Management Fees

Fidelity SAI U.S. Treasury Bond Index Fund

Based on its review, the Board concluded that the nature, extent, and quality of services provided to the fund under the Advisory Contracts should continue to benefit the shareholders of the fund.

Fidelity SAI U.S. Treasury Bond Index Fund

The Board noted that the fund's management fee rate ranked below the median of its Total Mapped Group and below the median of its ASPG for 2017.

Based on its review, the Board concluded that the fund's management fee is fair and reasonable in light of the services that the fund receives and the other factors considered.

The Board noted that the fund's total expense ratio ranked below the competitive median for 2017.

The Board concluded, taking into account the analysis of the Economies of Scale Committee, that economies of scale, if any, are being appropriately shared between fund shareholders and Fidelity.

Fidelity Investments

UYB-ANN-0419
1.9872606.102

Fidelity® Short-Term Treasury Bond Index Fund

Fidelity® Intermediate Treasury Bond Index Fund

Fidelity® Long-Term Treasury Bond Index Fund

Annual Report

February 28, 2019

Account Type	Website	Phone Number
Brokerage, Mutual Fund, or Annuity Contracts:	fidelity.com/mailpreferences	1-800-343-3548
Employer Provided Retirement Accounts:	netbenefits.fidelity.com/preferences (choose 'no' under Required Disclosures to continue to print)	1-800-343-0860
Advisor Sold Accounts Serviced Through Your Financial Intermediary:	Contact Your Financial Intermediary	Your Financial Intermediary's phone number
Advisor Sold Accounts Serviced by Fidelity:	institutional.fidelity.com	1-877-208-0098

Contents

Performance
Management's Discussion of Fund Performance
Fidelity® Short-Term Treasury Bond Index Fund
Investment Summary
Schedule of Investments
Financial Statements
Fidelity® Intermediate Treasury Bond Index Fund
Investment Summary
Schedule of Investments
Financial Statements
Fidelity® Long-Term Treasury Bond Index Fund
Investment Summary
Schedule of Investments
Financial Statements
Notes to Financial Statements
Report of Independent Registered Public Accounting Firm
Trustees and Officers
Shareholder Expense Example
Distributions
Board Approval of Investment Advisory Contracts and Management Fees

You may also call 1-800-544-8544 to request a free copy of the proxy voting guidelines.

Standard & Poor's, S&P and S&P 500 are registered service marks of The McGraw-Hill Companies, Inc. and have been licensed for use by Fidelity Distributors Corporation.

Other third-party marks appearing herein are the property of their respective owners.

This report and the financial statements contained herein are submitted for the general information of the shareholders of the Funds. This report is not authorized for distribution to prospective investors in the Funds unless preceded or accompanied by an effective prospectus.

NOT FDIC INSURED •MAY LOSE VALUE •NO BANK GUARANTEE

Neither the Funds nor Fidelity Distributors Corporation is a bank.

Fidelity® Short-Term Treasury Bond Index Fund

Performance: The Bottom Line

Average Annual Total Returns

Periods ended February 28, 2019	Past 1 year	Past 5 years	Past 10 years
Fidelity® Short-Term Treasury Bond Index Fund	2.53%	0.93%	1.35%
Bloomberg Barclays U.S. 1-5 Year Treasury Bond Index	2.61%	1.02%	1.45%

The initial offering of Fidelity Short-Term Treasury Bond Index Fund (formerly named Institutional Premium Class) took place on October 4, 2017. Returns prior to October 4, 2017 are those of the former Premium Class and have not been restated to reflect current expenses.

$10,000 Over 10 Years

Let's say hypothetically that $10,000 was invested in Fidelity® Short-Term Treasury Bond Index Fund on February 28, 2009.

The chart shows how the value of your investment would have changed, and also shows how the Bloomberg Barclays U.S. 1-5 Year Treasury Bond Index performed over the same period.

	Period Ending Values
	$11,440	Fidelity® Short-Term Treasury Bond Index Fund
	$11,552	Bloomberg Barclays U.S. 1-5 Year Treasury Bond Index

Fidelity® Intermediate Treasury Bond Index Fund

Performance: The Bottom Line

Average Annual Total Returns

Periods ended February 28, 2019	Past 1 year	Past 5 years	Past 10 years
Fidelity® Intermediate Treasury Bond Index Fund	4.02%	2.01%	3.10%
Bloomberg Barclays U.S. 5-10 Year Treasury Bond Index	4.17%	2.11%	3.21%

The initial offering of Fidelity Intermediate Treasury Bond Index Fund (formerly named Institutional Premium Class) took place on October 4, 2017. Returns prior to October 4, 2017 are those of the former Premium Class and have not been restated to reflect current expenses.

$10,000 Over 10 Years

Let's say hypothetically that $10,000 was invested in Fidelity® Intermediate Treasury Bond Index Fund on February 28, 2009.

The chart shows how the value of your investment would have changed, and also shows how the Bloomberg Barclays U.S. 5-10 Year Treasury Bond Index performed over the same period.

	Period Ending Values
	$13,576	Fidelity® Intermediate Treasury Bond Index Fund
	$13,720	Bloomberg Barclays U.S. 5-10 Year Treasury Bond Index

Fidelity® Long-Term Treasury Bond Index Fund

Performance: The Bottom Line

Average Annual Total Returns

Periods ended February 28, 2019	Past 1 year	Past 5 years	Past 10 years
Fidelity® Long-Term Treasury Bond Index Fund	3.94%	4.38%	4.99%
Bloomberg Barclays U.S. Long Treasury Bond Index	3.99%	4.51%	5.08%

The initial offering of Fidelity Long-Term Treasury Bond Index Fund (formerly named Institutional Premium Class) took place on October 4, 2017. Returns prior to October 4, 2017 are those of the former Premium Class and have not been restated to reflect current expenses.

$10,000 Over 10 Years

Let's say hypothetically that $10,000 was invested in Fidelity® Long-Term Treasury Bond Index Fund on February 28, 2009.

The chart shows how the value of your investment would have changed, and also shows how the Bloomberg Barclays U.S. Long Treasury Bond Index performed over the same period.

	Period Ending Values
	$16,274	Fidelity® Long-Term Treasury Bond Index Fund
	$16,416	Bloomberg Barclays U.S. Long Treasury Bond Index

Management's Discussion of Fund Performance

Comments from Co-Portfolio Managers Brandon Bettencourt and Jay Small: For the fiscal year, the Fidelity Treasury Bond Index Funds posted positive returns that were roughly in line, net of fees, with the returns of their respective Bloomberg Barclays benchmarks. (For specific portfolio results, please refer to the Performance sections of this report.) These results met our goal of producing monthly returns, before expenses, that closely match the benchmark's returns. We use a method known as stratified sampling, which matches the index's risk factors, but does not always hold all bonds in the exact proportions of the index. From March through November 2018, U.S. Treasuries were under pressure due to rising interest rates and expectations for further policy rate increases by the Federal Reserve. Another factor weighing on U.S. Treasuries was the Fed’s decision to begin reducing the $4.5 trillion in government securities it accumulated as part of the quantitative easing program it deployed to battle the recession and financial crisis a decade ago. That said, from December through period end, U.S. Treasury prices rallied strongly after the Fed made a dovish pivot, indicating that the case for raising interest rates had weakened somewhat with slowing global economic growth and muted inflation. Moreover, the Fed communicated that it would be patient in assessing the need for further interest rate hikes. Against this backdrop, the yield curve flattened and both intermediate- and long-term U.S. Treasuries outperformed their shorter-term counterparts.

Fidelity® Short-Term Treasury Bond Index Fund

Investment Summary (Unaudited)

Coupon Distribution as of February 28, 2019

	% of fund's investments
1 - 1.99%	40.6
2 - 2.99%	56.1
3 - 3.99%	2.1
7 - 7.99%	0.5
8 - 8.99%	0.5

Coupon distribution shows the range of stated interest rates on the fund's investments, excluding short-term investments.

Asset Allocation (% of fund's net assets)

As of February 28, 2019
	U.S. Treasury Obligations	99.5%
	Short-Term Investments and Net Other Assets (Liabilities)	0.5%

Fidelity® Short-Term Treasury Bond Index Fund

Schedule of Investments February 28, 2019

Showing Percentage of Net Assets

U.S. Government and Government Agency Obligations - 99.5%
	Principal Amount	Value
U.S. Treasury Obligations - 99.5%
U.S. Treasury Bonds:
7.125% 2/15/23	$5,393,000	$6,319,501
7.25% 8/15/22	1,725,000	1,992,442
7.875% 2/15/21	804,000	885,405
8% 11/15/21	3,503,000	4,001,356
8.125% 5/15/21	599,000	670,225
8.125% 8/15/21	1,388,000	1,571,314
8.75% 5/15/20	313,000	335,913
8.75% 8/15/20	2,043,000	2,222,241
U.S. Treasury Notes:
1.125% 3/31/20	6,056,000	5,964,450
1.125% 4/30/20	8,108,000	7,976,245
1.125% 2/28/21	11,891,000	11,565,391
1.125% 6/30/21	11,953,000	11,583,204
1.125% 7/31/21	11,753,000	11,371,946
1.125% 8/31/21	12,394,000	11,978,607
1.125% 9/30/21	11,925,000	11,518,805
1.25% 3/31/21	20,186,000	19,673,465
1.25% 10/31/21	11,811,000	11,428,988
1.25% 7/31/23	12,011,000	11,373,854
1.375% 3/31/20	12,665,000	12,505,698
1.375% 4/30/20	12,800,000	12,628,000
1.375% 5/31/20	8,975,000	8,844,582
1.375% 8/31/20	12,521,000	12,304,817
1.375% 9/15/20	8,702,000	8,547,336
1.375% 9/30/20	13,154,000	12,911,473
1.375% 10/31/20	20,545,000	20,148,546
1.375% 1/31/21	12,117,700	11,852,625
1.375% 4/30/21	12,673,000	12,367,561
1.375% 5/31/21	11,691,000	11,399,182
1.375% 6/30/23	8,271,000	7,882,651
1.375% 8/31/23	12,240,000	11,643,778
1.375% 9/30/23	8,447,000	8,027,620
1.5% 4/15/20	7,968,000	7,876,492
1.5% 5/15/20	8,145,000	8,043,188
1.5% 5/31/20	12,412,000	12,251,032
1.5% 6/15/20	8,857,000	8,737,984
1.5% 7/15/20	7,478,000	7,370,796
1.5% 8/15/20	8,743,000	8,610,830
1.5% 1/31/22	10,339,000	10,050,235
1.5% 2/28/23	10,218,000	9,823,250
1.5% 3/31/23	9,950,000	9,557,830
1.625% 3/15/20	8,771,000	8,687,401
1.625% 6/30/20	12,278,000	12,125,964
1.625% 7/31/20	12,462,000	12,299,410
1.625% 10/15/20	9,331,000	9,192,129
1.625% 11/30/20	13,095,000	12,887,321
1.625% 8/15/22	8,171,000	7,930,977
1.625% 8/31/22	20,192,000	19,594,916
1.625% 11/15/22	11,261,000	10,907,334
1.625% 4/30/23	8,893,000	8,579,313
1.625% 5/31/23	11,847,000	11,419,860
1.625% 10/31/23	8,974,000	8,619,597
1.75% 10/31/20	10,401,000	10,263,268
1.75% 11/15/20	8,590,000	8,475,243
1.75% 12/31/20	12,478,800	12,300,392
1.75% 11/30/21	12,863,000	12,605,740
1.75% 2/28/22	9,953,000	9,738,388
1.75% 3/31/22	9,549,000	9,338,251
1.75% 4/30/22	10,280,000	10,047,495
1.75% 5/15/22	9,373,000	9,154,785
1.75% 5/31/22	20,104,000	19,632,027
1.75% 6/30/22	11,930,000	11,646,197
1.75% 9/30/22	11,033,000	10,745,970
1.75% 1/31/23	12,257,000	11,906,048
1.75% 5/15/23	16,520,000	16,010,848
1.875% 6/30/20	5,671,000	5,620,271
1.875% 12/15/20	7,334,000	7,247,482
1.875% 11/30/21	9,875,000	9,711,831
1.875% 1/31/22	11,709,000	11,501,348
1.875% 2/28/22	20,108,000	19,743,543
1.875% 3/31/22	13,767,000	13,516,935
1.875% 4/30/22	12,031,000	11,803,069
1.875% 5/31/22	9,884,000	9,690,181
1.875% 7/31/22	20,177,000	19,760,849
1.875% 8/31/22	10,725,000	10,497,513
1.875% 9/30/22	12,723,000	12,447,666
1.875% 10/31/22	11,029,000	10,782,571
2% 7/31/20	9,051,000	8,979,582
2% 9/30/20	7,154,000	7,092,520
2% 11/30/20	8,253,000	8,174,983
2% 1/15/21	8,625,000	8,538,750
2% 2/28/21	7,499,000	7,420,202
2% 5/31/21	9,495,000	9,387,810
2% 8/31/21	10,283,000	10,154,864
2% 10/31/21	10,347,000	10,212,004
2% 11/15/21	14,721,000	14,531,812
2% 12/31/21	13,628,000	13,444,341
2% 2/15/22	11,413,000	11,252,950
2% 7/31/22	10,059,000	9,891,612
2% 10/31/22	12,851,000	12,619,582
2% 11/30/22	22,760,000	22,339,473
2% 2/15/23	17,183,000	16,847,395
2.125% 8/31/20	9,215,000	9,154,887
2.125% 1/31/21	8,359,000	8,293,695
2.125% 6/30/21	9,518,000	9,434,346
2.125% 8/15/21	13,989,000	13,859,493
2.125% 9/30/21	10,087,000	9,989,676
2.125% 12/31/21	10,428,000	10,320,461
2.125% 6/30/22	11,177,000	11,042,527
2.125% 12/31/22	31,590,000	31,138,362
2.125% 11/30/23	9,799,000	9,621,776
2.25% 3/31/20	11,250,000	11,213,965
2.25% 2/15/21	10,235,000	10,178,228
2.25% 3/31/21	9,164,000	9,111,379
2.25% 4/30/21	10,147,000	10,088,338
2.25% 7/31/21	10,714,000	10,649,130
2.25% 12/31/23	8,696,000	8,584,922
2.25% 1/31/24	17,742,000	17,507,057
2.375% 4/30/20	19,219,000	19,178,460
2.375% 12/31/20	8,628,000	8,601,038
2.375% 3/15/21	9,239,000	9,209,767
2.375% 4/15/21	18,429,000	18,371,409
2.375% 1/31/23	20,070,000	19,962,594
2.5% 5/31/20	19,618,000	19,602,673
2.5% 6/30/20	17,821,000	17,806,381
2.5% 12/31/20	16,622,000	16,607,066
2.5% 1/31/21	17,868,000	17,857,530
2.5% 2/28/21	22,527,000	22,518,201
2.5% 1/15/22	14,380,000	14,377,753
2.5% 2/15/22	21,717,000	21,719,545
2.5% 3/31/23	13,815,000	13,804,207
2.5% 8/15/23	17,029,000	17,012,370
2.5% 1/31/24	20,224,000	20,201,880
2.625% 7/31/20	13,244,000	13,254,347
2.625% 8/15/20	12,028,000	12,037,397
2.625% 8/31/20	20,749,000	20,767,642
2.625% 11/15/20	21,928,000	21,951,127
2.625% 5/15/21	18,798,000	18,836,918
2.625% 6/15/21	19,206,000	19,253,265
2.625% 7/15/21	14,140,000	14,175,350
2.625% 12/15/21	15,274,000	15,325,311
2.625% 2/28/23	14,105,000	14,160,649
2.625% 6/30/23	12,113,000	12,162,682
2.625% 12/31/23	22,759,000	22,853,236
2.75% 9/30/20	15,467,000	15,511,105
2.75% 11/30/20	16,773,000	16,828,036
2.75% 8/15/21	14,165,000	14,244,125
2.75% 9/15/21	15,324,000	15,414,388
2.75% 4/30/23	14,417,000	14,544,275
2.75% 5/31/23	16,964,000	17,117,736
2.75% 7/31/23	15,445,000	15,588,590
2.75% 8/31/23	14,357,000	14,496,644
2.75% 11/15/23	20,362,000	20,560,052
2.75% 2/15/24	18,464,000	18,647,919
2.875% 10/31/20	15,845,000	15,925,463
2.875% 10/15/21	15,210,000	15,348,435
2.875% 11/15/21	15,618,000	15,765,029
2.875% 9/30/23	15,804,000	16,037,973
2.875% 10/31/23	13,864,000	14,071,960
2.875% 11/30/23	13,992,000	14,212,265
3.125% 5/15/21	11,041,000	11,181,600
3.5% 5/15/20	10,790,000	10,908,437
3.625% 2/15/21	16,459,000	16,799,753
		1,878,139,696
TOTAL U.S. GOVERNMENT AND GOVERNMENT AGENCY OBLIGATIONS
(Cost $1,891,278,697)		1,878,139,696
	Shares	Value

Money Market Funds - 0.3%
Fidelity Cash Central Fund, 2.44% (a)
(Cost $5,788,231)	5,787,074	5,788,231
TOTAL INVESTMENT IN SECURITIES - 99.8%
(Cost $1,897,066,928)		1,883,927,927
NET OTHER ASSETS (LIABILITIES) - 0.2%		2,953,520
NET ASSETS - 100%		$1,886,881,447

Legend

Affiliated Central Funds

Information regarding fiscal year to date income earned by the Fund from investments in Fidelity Central Funds is as follows:

Fund	Income earned
Fidelity Cash Central Fund	$32,316
Total	$32,316

Investment Valuation

	Valuation Inputs at Reporting Date:
Description	Total	Level 1	Level 2	Level 3
Investments in Securities:
U.S. Government and Government Agency Obligations	$1,878,139,696	$--	$1,878,139,696	$--
Money Market Funds	5,788,231	5,788,231	--	--
Total Investments in Securities:	$1,883,927,927	$5,788,231	$1,878,139,696	$--

See accompanying notes which are an integral part of the financial statements.

Fidelity® Short-Term Treasury Bond Index Fund

Financial Statements

Statement of Assets and Liabilities

		February 28, 2019
Assets
Investment in securities, at value — See accompanying schedule: Unaffiliated issuers (cost $1,891,278,697)	$1,878,139,696
Fidelity Central Funds (cost $5,788,231)	5,788,231
Total Investment in Securities (cost $1,897,066,928)		$1,883,927,927
Receivable for investments sold		64,270,147
Receivable for fund shares sold		9,088,972
Interest receivable		8,127,790
Distributions receivable from Fidelity Central Funds		3,743
Total assets		1,965,418,579
Liabilities
Payable for investments purchased	$77,131,957
Payable for fund shares redeemed	898,025
Distributions payable	463,153
Accrued management fee	43,997
Total liabilities		78,537,132
Net Assets		$1,886,881,447
Net Assets consist of:
Paid in capital		$1,908,623,700
Total distributable earnings (loss)		(21,742,253)
Net Assets		$1,886,881,447
Net Asset Value and Maximum Offering Price
Net Asset Value, offering price and redemption price per share ($1,886,881,447 ÷ 183,140,092 shares)		$10.30

See accompanying notes which are an integral part of the financial statements.

Statement of Operations

		Year ended February 28, 2019
Investment Income
Interest		$29,801,561
Income from Fidelity Central Funds		32,316
Total income		29,833,877
Expenses
Management fee	$477,086
Transfer agent fees	253,861
Independent trustees' fees and expenses	7,087
Commitment fees	4,220
Total expenses before reductions	742,254
Expense reductions	(252)
Total expenses after reductions		742,002
Net investment income (loss)		29,091,875
Realized and Unrealized Gain (Loss)
Net realized gain (loss) on:
Investment securities:
Unaffiliated issuers	(7,853,211)
Fidelity Central Funds	(6)
Total net realized gain (loss)		(7,853,217)
Change in net unrealized appreciation (depreciation) on investment securities		19,652,990
Net gain (loss)		11,799,773
Net increase (decrease) in net assets resulting from operations		$40,891,648

See accompanying notes which are an integral part of the financial statements.

Statement of Changes in Net Assets

	Year ended February 28, 2019	Year ended February 28, 2018
Increase (Decrease) in Net Assets
Operations
Net investment income (loss)	$29,091,875	$20,297,233
Net realized gain (loss)	(7,853,217)	(3,141,212)
Change in net unrealized appreciation (depreciation)	19,652,990	(24,593,919)
Net increase (decrease) in net assets resulting from operations	40,891,648	(7,437,898)
Distributions to shareholders	(27,261,371)	–
Distributions to shareholders from net investment income	–	(19,383,387)
Total distributions	(27,261,371)	(19,383,387)
Share transactions - net increase (decrease)	334,964,244	160,444,085
Total increase (decrease) in net assets	348,594,521	133,622,800
Net Assets
Beginning of period	1,538,286,926	1,404,664,126
End of period	$1,886,881,447	$1,538,286,926
Other Information
Undistributed net investment income end of period		$1,424,805

See accompanying notes which are an integral part of the financial statements.

Financial Highlights

Fidelity Short-Term Treasury Bond Index Fund

Years ended February 28,	2019	2018 ^A
Selected Per–Share Data
Net asset value, beginning of period	$10.22	$10.40
Income from Investment Operations
Net investment income (loss)^B	.191	.061
Net realized and unrealized gain (loss)	.065	(.182)
Total from investment operations	.256	(.121)
Distributions from net investment income	(.176)	(.059)
Distributions from net realized gain	–	–
Total distributions	(.176)	(.059)
Net asset value, end of period	$10.30	$10.22
Total Return^C,^D	2.53%	(1.17)%
Ratios to Average Net Assets^E,^F
Expenses before reductions	.03%	.03%^G
Expenses net of fee waivers, if any	.03%	.03%^G
Expenses net of all reductions	.03%	.03%^G
Net investment income (loss)	1.85%	1.49%^G
Supplemental Data
Net assets, end of period (000 omitted)	$1,886,881	$483
Portfolio turnover rate^H	46%	41%

^A For the period October 4, 2017 (commencement of sale of shares) to February 28, 2018.

^B Calculated based on average shares outstanding during the period.

^C Total returns for periods of less than one year are not annualized.

^D Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

^F Expense ratios reflect operating expenses of the Fund. Expenses before reductions do not reflect amounts reimbursed by the investment adviser or reductions from expense offset arrangements and do not represent the amount paid by the Fund during periods when reimbursements or reductions occur. Expenses net of fee waivers reflect expenses after reimbursement by the investment adviser but prior to reductions from expense offset arrangements. Expenses net of all reductions represent the net expenses paid by the Fund.

^G Annualized

^H Amount does not include the portfolio activity of any underlying Fidelity Central Funds.

See accompanying notes which are an integral part of the financial statements.

Fidelity® Intermediate Treasury Bond Index Fund

Investment Summary (Unaudited)

Coupon Distribution as of February 28, 2019

	% of fund's investments
1 - 1.99%	10.0
2 - 2.99%	79.7
3 - 3.99%	7.1
5 - 5.99%	0.5
6 - 6.99%	1.7
7 - 7.99%	0.3

Coupon distribution shows the range of stated interest rates on the fund's investments, excluding short-term investments.

Asset Allocation (% of fund's net assets)

As of February 28, 2019
	U.S. Treasury Obligations	99.5%
	Short-Term Investments and Net Other Assets (Liabilities)	0.5%

Fidelity® Intermediate Treasury Bond Index Fund

Schedule of Investments February 28, 2019

Showing Percentage of Net Assets

U.S. Government and Government Agency Obligations - 99.5%
	Principal Amount	Value
U.S. Treasury Obligations - 99.5%
U.S. Treasury Bonds:
5.25% 11/15/28	$5,903,000	$7,166,150
5.5% 8/15/28	3,619,000	4,453,491
6% 2/15/26	6,687,000	8,112,689
6.125% 11/15/27	7,302,000	9,232,181
6.375% 8/15/27	4,370,000	5,583,699
6.5% 11/15/26	3,128,000	3,963,763
6.625% 2/15/27	3,211,000	4,121,494
6.75% 8/15/26	3,119,000	3,984,401
6.875% 8/15/25	3,922,000	4,910,313
7.5% 11/15/24	2,667,000	3,360,003
7.625% 2/15/25	3,128,000	3,991,866
U.S. Treasury Notes:
1.5% 8/15/26	79,666,000	73,516,781
1.625% 2/15/26	63,130,000	59,107,928
1.625% 5/15/26	75,980,000	70,964,133
1.875% 8/31/24	27,605,000	26,645,295
2% 4/30/24	28,083,000	27,343,627
2% 5/31/24	40,247,000	39,166,934
2% 6/30/24	23,672,000	23,017,321
2% 2/15/25	82,289,000	79,595,321
2% 8/15/25	64,173,000	61,854,249
2% 11/15/26	72,315,000	69,029,752
2.125% 2/29/24	29,383,000	28,813,704
2.125% 3/31/24	27,956,000	27,401,248
2.125% 7/31/24	28,816,000	28,181,148
2.125% 9/30/24	40,165,000	39,239,322
2.125% 11/30/24	26,850,000	26,202,873
2.125% 5/15/25	64,493,000	62,732,039
2.25% 10/31/24	27,273,000	26,813,833
2.25% 11/15/24	65,182,000	64,048,954
2.25% 12/31/24	28,613,000	28,101,096
2.25% 11/15/25	82,146,200	80,272,240
2.25% 2/15/27	61,408,000	59,596,944
2.25% 8/15/27	78,970,000	76,388,051
2.25% 11/15/27	78,683,000	75,965,978
2.375% 2/29/24	36,391,000	36,147,919
2.375% 8/15/24	82,085,000	81,289,802
2.375% 5/15/27	63,687,000	62,318,724
2.5% 5/15/24	79,846,000	79,646,385
2.5% 1/31/25	27,209,000	27,082,521
2.5% 2/28/26	24,399,000	24,207,430
2.625% 3/31/25	41,025,000	41,095,512
2.625% 12/31/25	32,859,000	32,878,253
2.625% 1/31/26	44,423,000	44,447,294
2.625% 2/15/29	34,075,000	33,792,816
2.75% 2/28/25	29,640,000	29,906,297
2.75% 6/30/25	30,747,000	31,007,629
2.75% 8/31/25	25,842,000	26,052,976
2.75% 2/15/28	65,524,000	65,769,715
2.875% 4/30/25	40,913,000	41,557,060
2.875% 5/31/25	34,321,000	34,858,606
2.875% 7/31/25	29,658,000	30,126,040
2.875% 11/30/25	31,543,000	32,038,324
2.875% 5/15/28	77,199,000	78,236,362
2.875% 8/15/28	70,980,000	71,900,522
3% 9/30/25	34,374,000	35,172,927
3% 10/31/25	33,239,000	34,014,144
3.125% 11/15/28	91,372,000	94,491,495
		2,280,917,574
TOTAL U.S. GOVERNMENT AND GOVERNMENT AGENCY OBLIGATIONS
(Cost $2,285,595,550)		2,280,917,574
	Shares	Value

Money Market Funds - 0.5%
Fidelity Cash Central Fund, 2.44% (a)
(Cost $12,130,238)	12,131,638	12,134,064
TOTAL INVESTMENT IN SECURITIES - 100.0%
(Cost $2,297,725,788)		2,293,051,638
NET OTHER ASSETS (LIABILITIES) - 0.0%		(301,539)
NET ASSETS - 100%		$2,292,750,099

Legend

Affiliated Central Funds

Information regarding fiscal year to date income earned by the Fund from investments in Fidelity Central Funds is as follows:

Fund	Income earned
Fidelity Cash Central Fund	$62,950
Total	$62,950

Investment Valuation

	Valuation Inputs at Reporting Date:
Description	Total	Level 1	Level 2	Level 3
Investments in Securities:
U.S. Government and Government Agency Obligations	$2,280,917,574	$--	$2,280,917,574	$--
Money Market Funds	12,134,064	12,134,064	--	--
Total Investments in Securities:	$2,293,051,638	$12,134,064	$2,280,917,574	$--

See accompanying notes which are an integral part of the financial statements.

Fidelity® Intermediate Treasury Bond Index Fund

Financial Statements

Statement of Assets and Liabilities

		February 28, 2019
Assets
Investment in securities, at value — See accompanying schedule: Unaffiliated issuers (cost $2,285,595,550)	$2,280,917,574
Fidelity Central Funds (cost $12,130,238)	12,134,064
Total Investment in Securities (cost $2,297,725,788)		$2,293,051,638
Receivable for investments sold		81,448,236
Receivable for fund shares sold		3,168,692
Interest receivable		10,579,422
Distributions receivable from Fidelity Central Funds		11,509
Total assets		2,388,259,497
Liabilities
Payable for investments purchased	$94,177,340
Payable for fund shares redeemed	919,922
Distributions payable	360,612
Accrued management fee	51,524
Total liabilities		95,509,398
Net Assets		$2,292,750,099
Net Assets consist of:
Paid in capital		$2,337,384,240
Total distributable earnings (loss)		(44,634,141)
Net Assets		$2,292,750,099
Net Asset Value and Maximum Offering Price
Net Asset Value, offering price and redemption price per share ($2,292,750,099 ÷ 217,471,032 shares)		$10.54

See accompanying notes which are an integral part of the financial statements.

Statement of Operations

		Year ended February 28, 2019
Investment Income
Interest		$50,090,833
Income from Fidelity Central Funds		62,950
Total income		50,153,783
Expenses
Management fee	$601,189
Transfer agent fees	213,609
Independent trustees' fees and expenses	8,931
Commitment fees	5,253
Total expenses before reductions	828,982
Expense reductions	(16)
Total expenses after reductions		828,966
Net investment income (loss)		49,324,817
Realized and Unrealized Gain (Loss)
Net realized gain (loss) on:
Investment securities:
Unaffiliated issuers	(34,438,263)
Fidelity Central Funds	(3,900)
Total net realized gain (loss)		(34,442,163)
Change in net unrealized appreciation (depreciation) on:
Investment securities:
Unaffiliated issuers	59,681,368
Fidelity Central Funds	3,825
Total change in net unrealized appreciation (depreciation)		59,685,193
Net gain (loss)		25,243,030
Net increase (decrease) in net assets resulting from operations		$74,567,847

See accompanying notes which are an integral part of the financial statements.

Statement of Changes in Net Assets

	Year ended February 28, 2019	Year ended February 28, 2018
Increase (Decrease) in Net Assets
Operations
Net investment income (loss)	$49,324,817	$32,220,488
Net realized gain (loss)	(34,442,163)	(8,508,996)
Change in net unrealized appreciation (depreciation)	59,685,193	(47,260,547)
Net increase (decrease) in net assets resulting from operations	74,567,847	(23,549,055)
Distributions to shareholders	(46,189,815)	–
Distributions to shareholders from net investment income	–	(30,612,509)
Total distributions	(46,189,815)	(30,612,509)
Share transactions - net increase (decrease)	573,625,017	242,085,424
Total increase (decrease) in net assets	602,003,049	187,923,860
Net Assets
Beginning of period	1,690,747,050	1,502,823,190
End of period	$2,292,750,099	$1,690,747,050
Other Information
Undistributed net investment income end of period		$2,761,837

See accompanying notes which are an integral part of the financial statements.

Financial Highlights

Fidelity Intermediate Treasury Bond Index Fund

Years ended February 28,	2019	2018 ^A
Selected Per–Share Data
Net asset value, beginning of period	$10.37	$10.77
Income from Investment Operations
Net investment income (loss)^B	.258	.091
Net realized and unrealized gain (loss)	.153	(.405)
Total from investment operations	.411	(.314)
Distributions from net investment income	(.241)	(.086)
Distributions from net realized gain	–	–
Total distributions	(.241)	(.086)
Net asset value, end of period	$10.54	$10.37
Total Return^C,^D	4.02%	(2.94)%
Ratios to Average Net Assets^E,^F
Expenses before reductions	.03%	.03%^G
Expenses net of fee waivers, if any	.03%	.03%^G
Expenses net of all reductions	.03%	.03%^G
Net investment income (loss)	2.47%	2.12%^G
Supplemental Data
Net assets, end of period (000 omitted)	$2,292,750	$97,998
Portfolio turnover rate^H	65%	43%

^A For the period October 4, 2017 (commencement of sale of shares) to February 28, 2018.

^B Calculated based on average shares outstanding during the period.

^C Total returns for periods of less than one year are not annualized.

^D Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

^F Expense ratios reflect operating expenses of the Fund. Expenses before reductions do not reflect amounts reimbursed by the investment adviser or reductions from expense offset arrangements and do not represent the amount paid by the Fund during periods when reimbursements or reductions occur. Expenses net of fee waivers reflect expenses after reimbursement by the investment adviser but prior to reductions from expense offset arrangements. Expenses net of all reductions represent the net expenses paid by the Fund.

^G Annualized

^H Amount does not include the portfolio activity of any underlying Fidelity Central Funds.

See accompanying notes which are an integral part of the financial statements.

Fidelity® Long-Term Treasury Bond Index Fund

Investment Summary (Unaudited)

Coupon Distribution as of February 28, 2019

	% of fund's investments
2 - 2.99%	27.5
3 - 3.99%	54.3
4 - 4.99%	14.0
5 - 5.99%	2.1
6 - 6.99%	1.3

Coupon distribution shows the range of stated interest rates on the fund's investments, excluding short-term investments.

Asset Allocation (% of fund's net assets)

As of February 28, 2019
	U.S. Treasury Obligations	99.4%
	Short-Term Investments and Net Other Assets (Liabilities)	0.6%

Fidelity® Long-Term Treasury Bond Index Fund

Schedule of Investments February 28, 2019

Showing Percentage of Net Assets

U.S. Government and Government Agency Obligations - 99.4%
	Principal Amount	Value
U.S. Treasury Obligations - 99.4%
U.S. Treasury Bonds:
2.25% 8/15/46	$76,189,000	$64,317,206
2.5% 2/15/45	81,556,000	73,002,178
2.5% 2/15/46	57,203,000	51,008,988
2.5% 5/15/46	75,621,000	67,382,447
2.75% 8/15/42	38,918,000	36,870,244
2.75% 11/15/42	46,868,000	44,345,184
2.75% 8/15/47	61,296,000	57,342,887
2.75% 11/15/47	62,001,000	57,958,826
2.875% 5/15/43	66,894,000	64,576,227
2.875% 8/15/45	65,387,500	62,930,361
2.875% 11/15/46	74,038,000	71,166,136
3% 5/15/42	26,591,000	26,337,555
3% 11/15/44	66,255,000	65,292,232
3% 5/15/45	62,938,000	62,045,559
3% 11/15/45	70,181,000	69,166,666
3% 2/15/47	62,578,000	61,671,108
3% 5/15/47	60,191,000	59,241,111
3% 2/15/48	66,460,000	65,302,142
3% 8/15/48	77,945,000	76,602,276
3% 2/15/49	31,530,000	31,005,321
3.125% 11/15/41	20,681,000	20,963,748
3.125% 2/15/42	40,517,000	41,032,959
3.125% 2/15/43	59,488,000	60,045,700
3.125% 8/15/44	80,863,300	81,476,092
3.125% 5/15/48	85,911,000	86,504,994
3.375% 5/15/44	80,349,300	84,504,865
3.375% 11/15/48	95,689,000	101,161,212
3.5% 2/15/39	23,332,000	25,336,182
3.625% 8/15/43	52,908,000	57,930,127
3.625% 2/15/44	65,994,000	72,299,521
3.75% 8/15/41	27,255,000	30,440,428
3.75% 11/15/43	75,869,000	84,748,044
3.875% 8/15/40	22,301,000	25,384,810
4.25% 5/15/39	14,218,000	17,039,940
4.25% 11/15/40	23,559,000	28,221,105
4.375% 2/15/38	12,671,000	15,429,417
4.375% 11/15/39	30,498,000	37,134,889
4.375% 5/15/40	32,027,000	39,000,379
4.375% 5/15/41	21,974,000	26,797,121
4.5% 2/15/36	21,822,000	26,708,082
4.5% 5/15/38	13,270,000	16,421,625
4.5% 8/15/39	28,808,000	35,653,276
4.625% 2/15/40	36,638,000	46,075,147
4.75% 2/15/37	7,363,000	9,325,412
4.75% 2/15/41	26,579,000	34,022,158
5% 5/15/37	18,133,000	23,656,482
5.375% 2/15/31	20,742,000	26,230,528
6.125% 8/15/29	7,682,900	10,040,890
6.25% 5/15/30	15,986,000	21,345,681
		2,352,495,468
TOTAL U.S. GOVERNMENT AND GOVERNMENT AGENCY OBLIGATIONS
(Cost $2,335,824,230)		2,352,495,468
	Shares	Value

Money Market Funds - 0.8%
Fidelity Cash Central Fund, 2.44% (a)
(Cost $18,627,628)	18,623,903	18,627,628
TOTAL INVESTMENT IN SECURITIES - 100.2%
(Cost $2,354,451,858)		2,371,123,096
NET OTHER ASSETS (LIABILITIES) - (0.2)%		(5,080,728)
NET ASSETS - 100%		$2,366,042,368

Legend

Affiliated Central Funds

Information regarding fiscal year to date income earned by the Fund from investments in Fidelity Central Funds is as follows:

Fund	Income earned
Fidelity Cash Central Fund	$87,149
Total	$87,149

Investment Valuation

	Valuation Inputs at Reporting Date:
Description	Total	Level 1	Level 2	Level 3
Investments in Securities:
U.S. Government and Government Agency Obligations	$2,352,495,468	$--	$2,352,495,468	$--
Money Market Funds	18,627,628	18,627,628	--	--
Total Investments in Securities:	$2,371,123,096	$18,627,628	$2,352,495,468	$--

See accompanying notes which are an integral part of the financial statements.

Fidelity® Long-Term Treasury Bond Index Fund

Financial Statements

Statement of Assets and Liabilities

		February 28, 2019
Assets
Investment in securities, at value — See accompanying schedule: Unaffiliated issuers (cost $2,335,824,230)	$2,352,495,468
Fidelity Central Funds (cost $18,627,628)	18,627,628
Total Investment in Securities (cost $2,354,451,858)		$2,371,123,096
Receivable for investments sold		13,054,095
Receivable for fund shares sold		10,652,846
Interest receivable		12,324,876
Distributions receivable from Fidelity Central Funds		17,362
Total assets		2,407,172,275
Liabilities
Payable for investments purchased	$39,208,451
Payable for fund shares redeemed	1,517,778
Distributions payable	348,475
Accrued management fee	55,203
Total liabilities		41,129,907
Net Assets		$2,366,042,368
Net Assets consist of:
Paid in capital		$2,447,827,524
Total distributable earnings (loss)		(81,785,156)
Net Assets		$2,366,042,368
Net Asset Value and Maximum Offering Price
Net Asset Value, offering price and redemption price per share ($2,366,042,368 ÷ 188,802,986 shares)		$12.53

See accompanying notes which are an integral part of the financial statements.

Statement of Operations

		Year ended February 28, 2019
Investment Income
Interest		$59,756,837
Income from Fidelity Central Funds		87,149
Total income		59,843,986
Expenses
Management fee	$584,410
Transfer agent fees	173,572
Independent trustees' fees and expenses	8,501
Commitment fees	4,932
Total expenses before reductions	771,415
Expense reductions	(101)
Total expenses after reductions		771,314
Net investment income (loss)		59,072,672
Realized and Unrealized Gain (Loss)
Net realized gain (loss) on:
Investment securities:
Unaffiliated issuers	(16,373,928)
Futures contracts	(72,660)
Total net realized gain (loss)		(16,446,588)
Change in net unrealized appreciation (depreciation) on investment securities		36,510,828
Net gain (loss)		20,064,240
Net increase (decrease) in net assets resulting from operations		$79,136,912

See accompanying notes which are an integral part of the financial statements.

Statement of Changes in Net Assets

	Year ended February 28, 2019	Year ended February 28, 2018
Increase (Decrease) in Net Assets
Operations
Net investment income (loss)	$59,072,672	$35,377,750
Net realized gain (loss)	(16,446,588)	(3,244,564)
Change in net unrealized appreciation (depreciation)	36,510,828	(49,340,413)
Net increase (decrease) in net assets resulting from operations	79,136,912	(17,207,227)
Distributions to shareholders	(58,089,893)	–
Distributions to shareholders from net investment income	–	(34,963,027)
Total distributions	(58,089,893)	(34,963,027)
Share transactions - net increase (decrease)	642,261,712	685,056,903
Total increase (decrease) in net assets	663,308,731	632,886,649
Net Assets
Beginning of period	1,702,733,637	1,069,846,988
End of period	$2,366,042,368	$1,702,733,637
Other Information
Undistributed net investment income end of period		$955,094

See accompanying notes which are an integral part of the financial statements.

Financial Highlights

Fidelity Long-Term Treasury Bond Index Fund

Years ended February 28,	2019	2018 ^A
Selected Per–Share Data
Net asset value, beginning of period	$12.42	$13.06
Income from Investment Operations
Net investment income (loss)^B	.381	.136
Net realized and unrealized gain (loss)	.101	(.627)
Total from investment operations	.482	(.491)
Distributions from net investment income	(.372)	(.149)
Total distributions	(.372)	(.149)
Net asset value, end of period	$12.53	$12.42
Total Return^C,^D	3.94%	(3.81)%
Ratios to Average Net Assets^E,^F
Expenses before reductions	.03%	.03%^G
Expenses net of fee waivers, if any	.03%	.03%^G
Expenses net of all reductions	.03%	.03%^G
Net investment income (loss)	3.04%	3.05%^G
Supplemental Data
Net assets, end of period (000 omitted)	$2,366,042	$314,669
Portfolio turnover rate^H	34%	24%

^A For the period October 4, 2017 (commencement of sale of shares) to February 28, 2018.

^B Calculated based on average shares outstanding during the period.

^C Total returns for periods of less than one year are not annualized.

^D Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

^F Expense ratios reflect operating expenses of the Fund. Expenses before reductions do not reflect amounts reimbursed by the investment adviser or reductions from expense offset arrangements and do not represent the amount paid by the Fund during periods when reimbursements or reductions occur. Expenses net of fee waivers reflect expenses after reimbursement by the investment adviser but prior to reductions from expense offset arrangements. Expenses net of all reductions represent the net expenses paid by the Fund.

^G Annualized

^H Amount does not include the portfolio activity of any underlying Fidelity Central Funds.

See accompanying notes which are an integral part of the financial statements.

Notes to Financial Statements

For the period ended February 28, 2019

1. Organization.

Fidelity Short-Term Treasury Bond Index Fund, Fidelity Intermediate Treasury Bond Index Fund and Fidelity Long-Term Treasury Bond Index Fund (the Funds) are funds of Fidelity Salem Street Trust (the Trust). Each Fund is authorized to issue an unlimited number of shares. The Trust is registered under the Investment Company Act of 1940, as amended (the 1940 Act), as an open-end management investment company organized as a Massachusetts business trust.

Effective November 2, 2018, each Fund's publicly offered share classes were consolidated into a single share class. The surviving classes are Fidelity Short-Term Treasury Bond Index Fund (formerly Institutional Premium Class), Fidelity Intermediate Treasury Bond Index Fund (formerly Institutional Premium Class), and Fidelity Long-Term Treasury Bond Index Fund (formerly Institutional Premium Class).

2. Investments in Fidelity Central Funds.

The Funds invest in Fidelity Central Funds, which are open-end investment companies generally available only to other investment companies and accounts managed by the investment adviser and its affiliates. The Funds' Schedules of Investments list each of the Fidelity Central Funds held as of period end, if any, as an investment of each Fund, but not include the underlying holdings of each Fidelity Central Fund. As an Investing Fund, each Fund indirectly bears its proportionate share of the expenses of the underlying Fidelity Central Funds.

A complete unaudited list of holdings for each Fidelity Central Fund is available upon request or at the Securities and Exchange Commission (the SEC) website at www.sec.gov. In addition, the financial statements of the Fidelity Central Funds, which are not covered by the Funds' Report of Independent Registered Public Accounting Firm, are available on the SEC website or upon request.

3. Significant Accounting Policies.

Each Fund is an investment company and applies the accounting and reporting guidance of the Financial Accounting Standards Board (FASB) Accounting Standards Codification Topic 946 Financial Services – Investments Companies. The financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP), which require management to make certain estimates and assumptions at the date of the financial statements. Actual results could differ from those estimates. Subsequent events, if any, through the date that the financial statements were issued have been evaluated in the preparation of the financial statements. The following summarizes the significant accounting policies of the Funds:

Investment Valuation. Investments are valued as of 4:00 p.m. Eastern time on the last calendar day of the period. The Board of Trustees (the Board) has delegated the day to day responsibility for the valuation of each Fund's investments to the Fair Value Committee (the Committee) established by each Fund's investment adviser. In accordance with valuation policies and procedures approved by the Board, each Fund attempts to obtain prices from one or more third party pricing vendors or brokers to value its investments. When current market prices, quotations or currency exchange rates are not readily available or reliable, investments will be fair valued in good faith by the Committee, in accordance with procedures adopted by the Board. Factors used in determining fair value vary by investment type and may include market or investment specific events, changes in interest rates and credit quality. The frequency with which these procedures are used cannot be predicted and they may be utilized to a significant extent. The Committee oversees each Fund's valuation policies and procedures and reports to the Board on the Committee's activities and fair value determinations. The Board monitors the appropriateness of the procedures used in valuing each Fund's investments and ratifies the fair value determinations of the Committee.

Each Fund categorizes the inputs to valuation techniques used to value its investments into a disclosure hierarchy consisting of three levels as shown below:

Level 1 – quoted prices in active markets for identical investments
Level 2 – other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, etc.)
Level 3 – unobservable inputs (including the Fund's own assumptions based on the best information available)

Valuation techniques used to value each Fund's investments by major category are as follows:

Investments in open-end mutual funds, including the Fidelity Central Funds, are valued at their closing net asset value (NAV) each business day and are categorized as Level 1 in the hierarchy.

Investment Transactions and Income. For financial reporting purposes, the Funds' investment holdings and NAV include trades executed through the end of the last business day of the period. The NAV per share for processing shareholder transactions is calculated as of the close of business of the New York Stock Exchange (NYSE), normally 4:00 p.m. Eastern time and includes trades executed through the end of the prior business day. Gains and losses on securities sold are determined on the basis of identified cost. Income and capital gain distributions from Fidelity Central Funds, if any, are recorded on the ex-dividend date. Interest income is accrued as earned and includes coupon interest and amortization of premium and accretion of discount on debt securities as applicable.

Class Allocations and Expenses. Investment income, realized and unrealized capital gains and losses, common expenses of each Fund, and certain fund-level expense reductions, if any, are allocated daily on a pro-rata basis to each class based on the relative net assets of each class to the total net assets of each Fund. Each class differs with respect to transfer agent fees incurred. Certain expense reductions may also differ by class. For the reporting period, the allocated portion of income and expenses to each class as a percent of its average net assets may vary due to the timing of recording these transactions in relation to fluctuating net assets of the classes. Expenses directly attributable to a fund are charged to that fund. Expenses attributable to more than one fund are allocated among the respective funds on the basis of relative net assets or other appropriate methods. Expense estimates are accrued in the period to which they relate and adjustments are made when actual amounts are known.

Income Tax Information and Distributions to Shareholders. Each year, each Fund intends to qualify as a regulated investment company under Subchapter M of the Internal Revenue Code, including distributing substantially all of its taxable income and realized gains. As a result, no provision for U.S. Federal income taxes is required. As of February 28, 2019, each Fund did not have any unrecognized tax benefits in the financial statements; nor is each Fund aware of any tax positions for which it is reasonably possible that the total amounts of unrecognized tax benefits will significantly change in the next twelve months. Each Fund files a U.S. federal tax return, in addition to state and local tax returns as required. Each Fund's federal income tax returns are subject to examination by the Internal Revenue Service (IRS) for a period of three fiscal years after they are filed. State and local tax returns may be subject to examination for an additional fiscal year depending on the jurisdiction.

Distributions are declared and recorded daily and paid monthly from net investment income. Distributions from realized gains, if any, are declared and recorded on the ex-dividend date. Income and capital gain distributions are declared separately for each class. Income and capital gain distributions are determined in accordance with income tax regulations, which may differ from GAAP.

Book-tax differences are primarily due to futures contracts, market discount, capital loss carryforwards and losses deferred due to wash sales.

As of period end, the cost and unrealized appreciation (depreciation) in securities, and derivatives if applicable, for federal income tax purposes were as follows for each Fund:

	Tax cost	Gross unrealized appreciation	Gross unrealized depreciation	Net unrealized appreciation (depreciation)
Fidelity Short-Term Treasury Bond Index Fund	$1,896,261,252	$5,338,081	$(17,671,406)	$(12,333,325)
Fidelity Intermediate Treasury Bond Index Fund	2,300,008,107	16,128,299	(23,084,768)	(6,956,469)
Fidelity Long-Term Treasury Bond Index Fund	2,365,434,831	47,457,199	(41,768,934)	5,688,265

The tax-based components of distributable earnings as of period end were as follows for each Fund:

	Capital loss carryforward	Net unrealized appreciation (depreciation) on securities and other investments
Fidelity Short-Term Treasury Bond Index Fund	$(9,179,076)	$(12,333,325)
Fidelity Intermediate Treasury Bond Index Fund	(37,320,446)	(6,956,469)
Fidelity Long-Term Treasury Bond Index Fund	(87,023,354)	5,688,265

Capital loss carryforwards are only available to offset future capital gains of the Funds to the extent provided by regulations and may be limited. Under the Regulated Investment Company Modernization Act of 2010 (the Act), the Funds are permitted to carry forward capital losses incurred in taxable years beginning after December 22, 2010 for an unlimited period and such capital losses are required to be used prior to any losses that expire. The capital loss carryforward information presented below, including any applicable limitation, is estimated as of fiscal period end and is subject to adjustment.

	No expiration
	Short-term	Long-term	Total no expiration	Total capital loss carryfoward
Fidelity Short-Term Treasury Bond Index Fund	$(3,130,783)	$(6,048,293)	$(9,179,076)	$(9,179,076)
Fidelity Intermediate Treasury Bond Index Fund	(8,008,455)	(29,311,991)	(37,320,446)	(37,320,446)
Fidelity Long-Term Treasury Bond Index Fund	(81,847,982)	(5,175,372)	(87,023,354)	(87,023,354)

The tax character of distributions paid was as follows:

February 28, 2019
	Ordinary Income	Long-term Capital Gains	Total
Fidelity Short-Term Treasury Bond Index Fund	$27,261,371	$–	$27,261,371
Fidelity Intermediate Treasury Bond Index Fund	46,189,815	–	46,189,815
Fidelity Long-Term Treasury Bond Index Fund	58,089,893	–	58,089,893

February 28, 2018
	Ordinary Income	Long-term Capital Gains	Total
Fidelity Short-Term Treasury Bond Index Fund	$19,383,387	$–	$19,383,387
Fidelity Intermediate Treasury Bond Index Fund	30,612,509	–	30,612,509
Fidelity Long-Term Treasury Bond Index Fund	34,963,027	–	34,963,027

New Rule Issuance. During August 2018, the U.S. Securities and Exchange Commission issued Final Rule Release No. 33-10532, Disclosure Update and Simplification. This Final Rule includes amendments specific to registered investment companies that are intended to eliminate overlap in disclosure requirements between Regulation S-X and GAAP. In accordance with these amendments, certain line-items in the Funds financial statements have been combined or removed for the current period as outlined in the table below.

Financial Statement	Current Line-Item Presentation (As Applicable)	Prior Line-Item Presentation (As Applicable)
Statement of Assets and Liabilities	Total distributable earnings (loss)	Undistributed/Distributions in excess of/Accumulated net investment income (loss) Accumulated/Undistributed net realized gain (loss) Net unrealized appreciation (depreciation)
Statement of Changes in Net Assets	N/A - removed	Undistributed/Distributions in excess of/Accumulated net investment income (loss) end of period
Statement of Changes in Net Assets	Distributions to shareholders	Distributions to shareholders from net investment income Distributions to shareholders from net realized gain
Distributions to Shareholders Note to Financial Statements	Distributions to shareholders	Distributions to shareholders from net investment income Distributions to shareholders from net realized gain

4. Fees and Other Transactions with Affiliates.

Management Fee and Expense Contract. Fidelity Management & Research Company (the investment adviser) and its affiliates provide the Funds with investment management related services for which the Funds pay a monthly management fee. The management fee is based on an annual rate of .03% of each Fund's average net assets. Under the management contract, the investment adviser pays all other fund-level expenses, except the compensation of the independent Trustees and certain other expenses such as interest expense, including commitment fees.

Effective August 1, 2018, the Board approved an amendment to the expense contract. Under the expense contract, the investment adviser pays class-level expenses as necessary so that the total expenses do not exceed an annual rate of .03% of class-level average net assets for Investor Class, Premium Class, Institutional Class and the corresponding Index Fund class of each Fund, with certain exceptions.

Prior to August 1, 2018, the investment adviser paid class-level expenses as necessary so that the total expenses did not exceed .16%, .06%, .04% and .03% for Investor Class, Premium Class, Institutional Class and the corresponding Index Fund class of each Fund, respectively, with certain exceptions.

Transfer Agent Fees. Fidelity Investments Institutional Operations Company, Inc. (FIIOC), an affiliate of the investment adviser, is the transfer, dividend disbursing and shareholder servicing agent for each class of the Funds. FIIOC receives transfer agent fees at an annual rate of .17%, .12%, .035%, and .015% of class-level average net assets for each Fund's Investor Class, Premium Class, Institutional Class, and the corresponding Index Fund class, respectively. FIIOC pays for typesetting, printing and mailing of shareholder reports, except proxy statements.

Effective August 1, 2018, under the amended expense contract, Investor Class, Premium Class, Institutional Class and the corresponding Index Fund class for each fund pays no transfer agent fees. Prior to August 1, 2018, the Investor Class, Premium Class, and Institutional for each fund paid a portion of the transfer agent fees at an annual rate of .13%, .03%, .01% of class-level average net assets, respectively. The corresponding Index Fund class for each Fund did not pay a transfer agent fee.

For the period, the total transfer agent fees paid by each applicable class were as follows:

	Amount	% of Class-Level Average Net Assets
Fidelity Short-Term Treasury Bond Index Fund
Investor Class	$90,033	.05
Premium Class	159,693	.01
Institutional Class	4,135	–^(a)
	$253,861
Fidelity Intermediate Treasury Bond Index Fund
Investor Class	$26,412	.07
Premium Class	176,998	.01
Institutional Class	10,199	–^(a)
	$213,609
Fidelity Long-Term Treasury Bond Index Fund
Investor Class	$24,287	.06
Premium Class	133,710	.01
Institutional Class	15,575	–^(a)
	$173,572

(a) Amount represents less than .005%.

Interfund Trades. The Funds may purchase from or sell securities to other Fidelity Funds under procedures adopted by the Board. The procedures have been designed to ensure these interfund trades are executed in accordance with Rule 17a-7 of the 1940 Act. Interfund trades are included within the respective purchases and sales amounts shown in the Purchases and Sales of Investments note.

5. Committed Line of Credit.

Certain Funds participate with other funds managed by the investment adviser or an affiliate in a $4.25 billion credit facility (the "line of credit") to be utilized for temporary or emergency purposes to fund shareholder redemptions or for other short-term liquidity purposes. The participating funds have agreed to pay commitment fees on their pro-rata portion of the line of credit, which are reflected in Commitment fees on the Statement of Operations, and are as follows:

Fidelity Short-Term Treasury Bond Index Fund	$4,220
Fidelity Intermediate Treasury Bond Index Fund	5,253
Fidelity Long-Term Treasury Bond Index Fund	4,932

During the period, the Funds did not borrow on this line of credit.

6. Security Lending.

Certain Funds lend portfolio securities from time to time in order to earn additional income. On the settlement date of the loan, each applicable Fund receives collateral (in the form of U.S. Treasury obligations, letters of credit and/or cash) against the loaned securities and maintains collateral in an amount not less than 100% of the market value of the loaned securities during the period of the loan. The market value of the loaned securities is determined at the close of business of the Funds and any additional required collateral is delivered to the Funds on the next business day. The Funds or borrower may terminate the loan at any time, and if the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, the Funds may apply collateral received from the borrower against the obligation. The Funds may experience delays and costs in recovering the securities loaned. Any cash collateral received is maintained at the Fund's custodian and/or invested in cash equivalents. At period end, there were no security loans outstanding. Security lending income represents the income earned on investing cash collateral, less rebates paid to borrowers, plus any premium payments received for lending certain types of securities. Security lending income is presented on each applicable Fund's Statement of Operations as a component of interest income. Security lending activity was as follows:

	Total Security Lending Income
Fidelity Intermediate Treasury Bond Index Fund	$88
Fidelity Long-Term Treasury Bond Index Fund	18,552

7. Expense Reductions.

Through arrangements with each applicable Fund's custodian, credits realized as a result of certain uninvested cash balances were used to reduce each applicable Fund's expenses as noted in the table below.

	Management fee reduction
Fidelity Short-Term Treasury Bond Index Fund	$252
Fidelity Intermediate Treasury Bond Index Fund	16
Fidelity Long-Term Treasury Bond Index Fund	101

8. Distributions to Shareholders.

Distributions to shareholders of each class were as follows:

	Year ended February 28, 2019	Year ended February 28, 2018^(a)
Fidelity Short-Term Treasury Bond Index Fund
Distributions to shareholders
Investor Class	$1,784,721	$–
Investor Class	13,748,854	–
Institutional Class	1,103,627	–
Fidelity Short-Term Treasury Bond Index Fund	10,624,169	–
Total	$27,261,371	$–
From net investment income
Investor Class	$–	$1,880,261
Premium Class	–	17,239,316
Institutional Class	–	262,063
Fidelity Short-Term Treasury Bond Index Fund	–	1,747
Total	$–	$19,383,387
Fidelity Intermediate Treasury Bond Index Fund
Distributions to shareholders
Investor Class	$589,086	$–
Premium Class	20,868,814	–
Institutional Class	3,867,593	–
Fidelity Intermediate Treasury Bond Index Fund	20,864,322	–
Total	$46,189,815	$–
From net investment income
Investor Class	$–	$889,333
Premium Class	–	28,530,416
Institutional Class	–	513,240
Fidelity Intermediate Treasury Bond Index Fund	–	679,520
Total	$–	$30,612,509
Fidelity Long-Term Treasury Bond Index Fund
Distributions to shareholders
Investor Class	$857,201	$–
Premium Class	21,771,433	–
Institutional Class	8,989,749	–
Fidelity Long-Term Treasury Bond Index Fund	26,471,510	–
Total	$58,089,893	$–
From net investment income
Investor Class	$–	$1,164,416
Premium Class	–	30,084,061
Institutional Class	–	3,274,411
Fidelity Long-Term Treasury Bond Index Fund	–	440,139
Total	$–	$34,963,027

(a) Distributions for Institutional Class and Institutional Premium Class are for the period October 4, 2017 (commencement of sale of shares) to February 28, 2018.

9. Share Transactions.

Share transactions for each class were as follows and may contain automatic conversions between classes or exchanges between affiliated funds:

	Shares	Shares	Dollars	Dollars
	Year ended February 28, 2019	Year endedFebruary 28, 2018^(a)	Year ended February 28, 2019	Year endedFebruary 28, 2018^(a)
Fidelity Short-Term Treasury Bond Index Fund
Investor Class
Shares sold	4,293,649	5,170,231	$43,755,619	$53,604,472
Reinvestment of distributions	151,410	158,693	1,543,880	1,643,965
Shares redeemed	(20,470,798)	(3,563,803)	(207,998,422)	(36,943,123)
Net increase (decrease)	(16,025,739)	1,765,121	$(162,698,923)	$18,305,314
Premium Class
Shares sold	29,979,364	61,708,133	$305,609,511	$640,022,832
Reinvestment of distributions	1,158,069	1,409,092	11,809,688	14,598,467
Shares redeemed	(158,849,988)	(56,291,631)	(1,615,146,865)	(582,815,661)
Net increase (decrease)	(127,712,555)	6,825,594	$(1,297,727,666)	$71,805,638
Institutional Class
Shares sold	8,529,316	9,131,603	$87,082,771	$94,261,659
Reinvestment of distributions	75,450	7,993	769,340	81,879
Shares redeemed	(15,363,131)	(2,381,231)	(156,311,632)	(24,498,785)
Net increase (decrease)	(6,758,365)	6,758,365	$(68,459,521)	$69,844,753
Fidelity Short-Term Treasury Bond Index Fund
Shares sold	211,797,304	47,064	$2,158,794,710	$486,633
Reinvestment of distributions	854,578	170	8,788,346	1,747
Shares redeemed	(29,559,024)	–	(303,732,702)	–
Net increase (decrease)	183,092,858	47,234	$1,863,850,354	$488,380
Fidelity Intermediate Treasury Bond Index Fund
Investor Class
Shares sold	1,562,466	3,750,437	$16,117,022	$40,035,591
Reinvestment of distributions	48,742	80,657	504,446	863,126
Shares redeemed	(6,475,865)	(3,878,705)	(66,523,920)	(41,503,973)
Net increase (decrease)	(4,864,657)	(47,611)	$(49,902,452)	$(605,256)
Premium Class
Shares sold	18,571,252	57,411,353	$191,920,080	$614,113,376
Reinvestment of distributions	1,886,546	2,445,561	19,508,381	26,168,049
Shares redeemed	(156,851,511)	(59,047,512)	(1,603,496,432)	(629,886,957)
Net increase (decrease)	(136,393,713)	809,402	$(1,392,067,971)	$10,394,468
Institutional Class
Shares sold	20,723,228	14,326,442	$214,627,119	$151,533,402
Reinvestment of distributions	316,875	17,000	3,275,365	176,889
Shares redeemed	(33,433,581)	(1,949,964)	(342,158,820)	(20,380,089)
Net increase (decrease)	(12,393,478)	12,393,478	$(124,256,336)	$131,330,202
Fidelity Intermediate Treasury Bond Index Fund
Shares sold	267,522,722	9,986,242	$2,757,229,222	$106,642,973
Reinvestment of distributions	1,717,824	164	17,999,312	1,735
Shares redeemed	(61,220,089)	(535,831)	(635,376,758)	(5,678,698)
Net increase (decrease)	208,020,457	9,450,575	$2,139,851,776	$100,966,010
Fidelity Long-Term Treasury Bond Index Fund
Investor Class
Shares sold	1,288,341	3,375,901	$16,005,600	$43,929,517
Reinvestment of distributions	61,054	81,541	760,780	1,058,185
Shares redeemed	(5,020,167)	(3,043,889)	(60,266,786)	(39,565,017)
Net increase (decrease)	(3,670,772)	413,553	$(43,500,406)	$5,422,685
Premium Class
Shares sold	29,986,385	45,483,996	$370,758,592	$591,712,312
Reinvestment of distributions	1,514,870	1,922,712	18,866,434	24,973,682
Shares redeemed	(111,732,972)	(47,473,757)	(1,328,152,965)	(615,311,298)
Net increase (decrease)	(80,231,717)	(67,049)	$(938,527,939)	$1,374,696
Institutional Class
Shares sold	24,472,930	29,404,196	$304,751,185	$385,228,333
Reinvestment of distributions	697,197	179,771	8,651,373	2,307,898
Shares redeemed	(53,010,192)	(1,743,902)	(627,362,187)	(22,131,619)
Net increase (decrease)	(27,840,065)	27,840,065	$(313,959,629)	$365,404,612
Fidelity Long-Term Treasury Bond Index Fund
Shares sold	198,213,868	25,311,325	$2,373,706,205	$312,631,304
Reinvestment of distributions	1,983,035	35,430	24,777,153	440,139
Shares redeemed	(36,723,378)	(17,294)	(460,233,672)	(216,533)
Net increase (decrease)	163,473,525	25,329,461	$1,938,249,686	$312,854,910

(a) Share transactions for Institutional Class and Institutional Premium Class are for the period October 4, 2017 (commencement of sale of shares) to February 28, 2018.

10. Other.

The Funds' organizational documents provide former and current trustees and officers with a limited indemnification against liabilities arising in connection with the performance of their duties to the Funds. In the normal course of business, the Funds may also enter into contracts that provide general indemnifications. The Funds' maximum exposure under these arrangements is unknown as this would be dependent on future claims that may be made against the Funds. The risk of material loss from such claims is considered remote.

Report of Independent Registered Public Accounting Firm

To the Board of Trustees of Fidelity Salem Street Trust and Shareholders of Fidelity Short-Term Treasury Bond Index Fund, Fidelity Intermediate Treasury Bond Index Fund and Fidelity Long-Term Treasury Bond Index Fund:

Opinions on the Financial Statements

We have audited the accompanying statements of assets and liabilities, including the schedules of investments, of Fidelity Short-Term Treasury Bond Index Fund, Fidelity Intermediate Treasury Bond Index Fund and Fidelity Long-Term Treasury Bond Index Fund (three of the funds constituting Fidelity Salem Street Trust, hereafter collectively referred to as the "Funds") as of February 28, 2019, the related statements of operations for the year ended February 28, 2019, the statements of changes in net assets for each of the two years in the period ended February 28, 2019, including the related notes, and the financial highlights for the year ended February 28, 2019 and for the period October 4, 2017 through February 28, 2018 (collectively referred to as the “financial statements”). In our opinion, the financial statements present fairly, in all material respects, the financial position of each of the Funds as of February 28, 2019, the results of each of their operations for the year then ended, the changes in each of their net assets for each of the two years in the period ended February 28, 2019 and each of the financial highlights for the year ended February 28, 2019 and for the period October 4, 2017 through February 28, 2018 in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinions

These financial statements are the responsibility of the Funds' management. Our responsibility is to express an opinion on the Funds' financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Funds in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

PricewaterhouseCoopers LLP

Boston, Massachusetts

April 12, 2019

We have served as the auditor of one or more investment companies in the Fidelity group of funds since 1932.

Trustees and Officers

The Trustees, Members of the Advisory Board (if any), and officers of the trust and funds, as applicable, are listed below. The Board of Trustees governs each fund and is responsible for protecting the interests of shareholders. The Trustees are experienced executives who meet periodically throughout the year to oversee each fund's activities, review contractual arrangements with companies that provide services to each fund, oversee management of the risks associated with such activities and contractual arrangements, and review each fund's performance. Except for Jonathan Chiel, each of the Trustees oversees 260 funds. Mr Chiel oversees 155 funds.

The Trustees hold office without limit in time except that (a) any Trustee may resign; (b) any Trustee may be removed by written instrument, signed by at least two-thirds of the number of Trustees prior to such removal; (c) any Trustee who requests to be retired or who has become incapacitated by illness or injury may be retired by written instrument signed by a majority of the other Trustees; and (d) any Trustee may be removed at any special meeting of shareholders by a two-thirds vote of the outstanding voting securities of the trust. Each Trustee who is not an interested person (as defined in the 1940 Act) of the trust and the funds is referred to herein as an Independent Trustee. Each Independent Trustee shall retire not later than the last day of the calendar year in which his or her 75th birthday occurs. The Independent Trustees may waive this mandatory retirement age policy with respect to individual Trustees. Officers and Advisory Board Members hold office without limit in time, except that any officer or Advisory Board Member may resign or may be removed by a vote of a majority of the Trustees at any regular meeting or any special meeting of the Trustees. Except as indicated, each individual has held the office shown or other offices in the same company for the past five years.

Each fund’s Statement of Additional Information (SAI) includes more information about the Trustees. To request a free copy, call Fidelity at 1-800-544-8544.

In determining that a particular Trustee was and continues to be qualified to serve as a Trustee, the Board has considered a variety of criteria, none of which, in isolation, was controlling. The Board believes that, collectively, the Trustees have balanced and diverse experience, qualifications, attributes, and skills, which allow the Board to operate effectively in governing each fund and protecting the interests of shareholders. Information about the specific experience, skills, attributes, and qualifications of each Trustee, which in each case led to the Board's conclusion that the Trustee should serve (or continue to serve) as a trustee of the funds, is provided below.

Board Structure and Oversight Function. Abigail P. Johnson is an interested person and currently serves as Chairman. The Trustees have determined that an interested Chairman is appropriate and benefits shareholders because an interested Chairman has a personal and professional stake in the quality and continuity of services provided to the funds. Independent Trustees exercise their informed business judgment to appoint an individual of their choosing to serve as Chairman, regardless of whether the Trustee happens to be independent or a member of management. The Independent Trustees have determined that they can act independently and effectively without having an Independent Trustee serve as Chairman and that a key structural component for assuring that they are in a position to do so is for the Independent Trustees to constitute a substantial majority for the Board. The Independent Trustees also regularly meet in executive session. Arthur E. Johnson serves as Chairman of the Independent Trustees and as such (i) acts as a liaison between the Independent Trustees and management with respect to matters important to the Independent Trustees and (ii) with management prepares agendas for Board meetings.

Fidelity^® funds are overseen by different Boards of Trustees. The funds' Board oversees Fidelity's investment-grade bond, money market, asset allocation and certain equity funds, and other Boards oversee Fidelity's high income and other equity funds. The asset allocation funds may invest in Fidelity^® funds that are overseen by such other Boards. The use of separate Boards, each with its own committee structure, allows the Trustees of each group of Fidelity^® funds to focus on the unique issues of the funds they oversee, including common research, investment, and operational issues. On occasion, the separate Boards establish joint committees to address issues of overlapping consequences for the Fidelity^® funds overseen by each Board.

The Trustees operate using a system of committees to facilitate the timely and efficient consideration of all matters of importance to the Trustees, each fund, and fund shareholders and to facilitate compliance with legal and regulatory requirements and oversight of the funds' activities and associated risks. The Board, acting through its committees, has charged FMR and its affiliates with (i) identifying events or circumstances the occurrence of which could have demonstrably adverse effects on the funds' business and/or reputation; (ii) implementing processes and controls to lessen the possibility that such events or circumstances occur or to mitigate the effects of such events or circumstances if they do occur; and (iii) creating and maintaining a system designed to evaluate continuously business and market conditions in order to facilitate the identification and implementation processes described in (i) and (ii) above. Because the day-to-day operations and activities of the funds are carried out by or through FMR, its affiliates, and other service providers, the funds' exposure to risks is mitigated but not eliminated by the processes overseen by the Trustees. While each of the Board's committees has responsibility for overseeing different aspects of the funds' activities, oversight is exercised primarily through the Operations and Audit Committees. In addition, an ad hoc Board committee of Independent Trustees has worked with FMR to enhance the Board's oversight of investment and financial risks, legal and regulatory risks, technology risks, and operational risks, including the development of additional risk reporting to the Board. Appropriate personnel, including but not limited to the funds' Chief Compliance Officer (CCO), FMR's internal auditor, the independent accountants, the funds' Treasurer and portfolio management personnel, make periodic reports to the Board's committees, as appropriate, including an annual review of Fidelity's risk management program for the Fidelity^® funds. The responsibilities of each standing committee, including their oversight responsibilities, are described further under "Standing Committees of the Trustees."

Interested Trustees*:

Correspondence intended for a Trustee who is an interested person may be sent to Fidelity Investments, 245 Summer Street, Boston, Massachusetts 02210.

Name, Year of Birth; Principal Occupations and Other Relevant Experience+

Jonathan Chiel (1957)

Year of Election or Appointment: 2016

Trustee

Abigail P. Johnson (1961)

Year of Election or Appointment: 2009

Trustee

Chairman of the Board of Trustees

Jennifer Toolin McAuliffe (1959)

Year of Election or Appointment: 2016

Trustee

* Determined to be an “Interested Trustee” by virtue of, among other things, his or her affiliation with the trust or various entities under common control with FMR.

Independent Trustees:

Correspondence intended for an Independent Trustee may be sent to Fidelity Investments, P.O. Box 55235, Boston, Massachusetts 02205-5235.

Name, Year of Birth; Principal Occupations and Other Relevant Experience+

Elizabeth S. Acton (1951)

Year of Election or Appointment: 2013

Trustee

Ann E. Dunwoody (1953)

Year of Election or Appointment: 2018

Trustee

John Engler (1948)

Year of Election or Appointment: 2014

Trustee

Robert F. Gartland (1951)

Year of Election or Appointment: 2010

Trustee

Arthur E. Johnson (1947)

Year of Election or Appointment: 2008

Trustee

Chairman of the Independent Trustees

Michael E. Kenneally (1954)

Year of Election or Appointment: 2009

Trustee

Vice Chairman of the Independent Trustees

Marie L. Knowles (1946)

Year of Election or Appointment: 2001

Trustee

Mark A. Murray (1954)

Year of Election or Appointment: 2016

Trustee

Advisory Board Members and Officers:

Correspondence intended for an officer may be sent to Fidelity Investments, 245 Summer Street, Boston, Massachusetts 02210. Officers appear below in alphabetical order.

Name, Year of Birth; Principal Occupation

Elizabeth Paige Baumann (1968)

Year of Election or Appointment: 2017

Anti-Money Laundering (AML) Officer

Craig S. Brown (1977)

Year of Election or Appointment: 2019

Assistant Treasurer

Mr. Brown also serves as Assistant Treasurer of other funds. Mr. Brown is an employee of Fidelity Investments (2013-present).

John J. Burke III (1964)

Year of Election or Appointment: 2018

Chief Financial Officer

William C. Coffey (1969)

Year of Election or Appointment: 2018

Secretary and Chief Legal Officer (CLO)

Jonathan Davis (1968)

Year of Election or Appointment: 2010

Assistant Treasurer

Adrien E. Deberghes (1967)

Year of Election or Appointment: 2010

Assistant Treasurer

Laura M. Del Prato (1964)

Year of Election or Appointment: 2018

President and Treasurer

Colm A. Hogan (1973)

Year of Election or Appointment: 2016

Assistant Treasurer

Chris Maher (1972)

Year of Election or Appointment: 2013

Assistant Treasurer

John B. McGinty, Jr. (1962)

Year of Election or Appointment: 2016

Chief Compliance Officer

Jason P. Pogorelec (1975)

Year of Election or Appointment: 2015

Assistant Secretary

Nancy D. Prior (1967)

Year of Election or Appointment: 2014

Vice President

Stacie M. Smith (1974)

Year of Election or Appointment: 2013

Assistant Treasurer

Marc L. Spector (1972)

Year of Election or Appointment: 2016

Deputy Treasurer

Jim Wegmann (1979)

Year of Election or Appointment: 2019

Assistant Treasurer

Mr. Wegmann also serves as Assistant Treasurer of other funds. Mr. Wegmann is an employee of Fidelity Investments (2011-present).

Shareholder Expense Example

As a shareholder of a Fund, you incur two types of costs: (1) transaction costs, and (2) ongoing costs, including management fees and other Fund expenses. This Example is intended to help you understand your ongoing costs (in dollars) of investing in the Funds and to compare these costs with the ongoing costs of investing in other mutual funds.

The Example is based on an investment of $1,000 invested at the beginning of the period and held for the entire period (September 1, 2018 to February 28, 2019).

Actual Expenses

The first line of the accompanying table for each fund provides information about actual account values and actual expenses. You may use the information in this line, together with the amount you invested, to estimate the expenses that you paid over the period. Simply divide your account value by $1,000.00 (for example, an $8,600 account value divided by $1,000.00 = 8.6), then multiply the result by the number in the first line for a fund under the heading entitled "Expenses Paid During Period" to estimate the expenses you paid on your account during this period. In addition, each Fund, as a shareholder in the underlying Fidelity Central Funds, will indirectly bear its pro-rata share of the fees and expenses incurred by the underlying Fidelity Central Funds. These fees and expenses are not included in the Fund's annualized expense ratio used to calculate the expense estimate in the table below.

Hypothetical Example for Comparison Purposes

The second line of the accompanying table for each fund provides information about hypothetical account values and hypothetical expenses based on a fund's actual expense ratio and an assumed rate of return of 5% per year before expenses, which is not the Fund's actual return. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period. You may use this information to compare the ongoing costs of investing in the Fund and other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of the other funds. In addition, each Fund, as a shareholder in the underlying Fidelity Central Funds, will indirectly bear its pro-rata share of the fees and expenses incurred by the underlying Fidelity Central Funds. These fees and expenses are not included in the Fund's annualized expense ratio used to calculate the expense estimate in the table below.

	Annualized Expense Ratio-^A	Beginning Account Value September 1, 2018	Ending Account Value February 28, 2019	Expenses Paid During Period-^B September 1, 2018 to February 28, 2019
Fidelity Short-Term Treasury Bond Index Fund	.03%
Actual		$1,000.00	$1,017.20	$.15
Hypothetical-^C		$1,000.00	$1,024.65	$.15
Fidelity Intermediate Treasury Bond Index Fund	.03%
Actual		$1,000.00	$1,025.80	$.15
Hypothetical-^C		$1,000.00	$1,024.65	$.15
Fidelity Long-Term Treasury Bond Index Fund	.03%
Actual		$1,000.00	$1,007.80	$.15
Hypothetical-^C		$1,000.00	$1,024.65	$.15

^A Annualized expense ratio reflects expenses net of applicable fee waivers.

^B Expenses are equal to the Fund's annualized expense ratio, multiplied by the average account value over the period, multiplied by 181/ 365 (to reflect the one-half year period).

^C 5% return per year before expenses

Distributions (Unaudited)

A percentage of the dividends distributed during the fiscal year for the following funds were derived from interest on U.S. Government securities which is generally exempt from state income tax:

Fidelity Short-Term Treasury Bond Index Fund	99.93%
Fidelity Intermediate Treasury Bond Index Fund	99.90%
Fidelity Long-Term Treasury Bond Index Fund	99.88%

The funds hereby designate the amounts noted below as distributions paid during the period January 1, 2019 to February 28, 2019 as qualifying to be taxed as interest-related dividends for nonresident alien shareholders:

Fidelity Short-Term Treasury Bond Index Fund	$5,333,000
Fidelity Intermediate Treasury Bond Index Fund	$7,588,382
Fidelity Long-Term Treasury Bond Index Fund	$10,365,793

The funds will notify shareholders in January 2020 of amounts for use in preparing 2019 income tax returns.

Board Approval of Investment Advisory Contracts and Management Fees

Fidelity Intermediate Treasury Bond Index Fund
Fidelity Long-Term Treasury Bond Index Fund
Fidelity Short-Term Treasury Bond Index Fund

Each year, the Board of Trustees, including the Independent Trustees (together, the Board), votes on the renewal of the management contract with Fidelity Management & Research Company (FMR) and the sub-advisory agreements (together, the Advisory Contracts) for each fund. FMR and the sub-advisers are referred to herein as the Investment Advisers. The Board, assisted by the advice of fund counsel and Independent Trustees' counsel, requests and considers a broad range of information relevant to the renewal of the Advisory Contracts throughout the year.

The Board meets regularly and, at each of its meetings, covers an extensive agenda of topics and materials and considers factors that are relevant to its annual consideration of the renewal of each fund's Advisory Contracts, including the services and support provided to each fund and its shareholders. The Board has established four standing committees (Committees) — Operations, Audit, Fair Valuation, and Governance and Nominating — each composed of and chaired by Independent Trustees with varying backgrounds, to which the Board has assigned specific subject matter responsibilities in order to enhance effective decision-making by the Board. The Operations Committee, of which all of the Independent Trustees are members, meets regularly throughout the year and considers, among other matters, information specifically related to the annual consideration of the renewal of each fund's Advisory Contracts. The Board, acting directly and through its Committees, requests and receives information concerning the annual consideration of the renewal of each fund's Advisory Contracts. The Board also meets as needed to review matters specifically related to the Board's annual consideration of the renewal of the Advisory Contracts. Members of the Board may also meet with trustees of other Fidelity funds through joint ad hoc committees to discuss certain matters relevant to all of the Fidelity funds.

At its September 2018 meeting, the Board unanimously determined to renew each fund's Advisory Contracts. In reaching its determination, the Board considered all factors it believed relevant, including (i) the nature, extent, and quality of the services to be provided to each fund and its shareholders (including the investment performance of each fund); (ii) the competitiveness of each fund's management fee and total expense ratio relative to peer funds; (iii) the total costs of the services to be provided by and the profits to be realized by Fidelity from its relationships with each fund; and (iv) the extent to which, if any, economies of scale exist and would be realized as each fund grows, and whether any economies of scale are appropriately shared with fund shareholders.

In considering whether to renew the Advisory Contracts for each fund, the Board reached a determination, with the assistance of fund counsel and Independent Trustees' counsel and through the exercise of its business judgment, that the renewal of the Advisory Contracts was in the best interests of each fund and its shareholders and that the compensation payable under the Advisory Contracts was fair and reasonable. The Board's decision to renew the Advisory Contracts was not based on any single factor, but rather was based on a comprehensive consideration of all the information provided to the Board at its meetings throughout the year. The Board, in reaching its determination to renew the Advisory Contracts, was aware that shareholders of each fund have a broad range of investment choices available to them, including a wide choice among funds offered by Fidelity's competitors, and that each fund's shareholders, who have the opportunity to review and weigh the disclosure provided by the fund in its prospectus and other public disclosures, have chosen to invest in that fund, which is part of the Fidelity family of funds.

Nature, Extent, and Quality of Services Provided. The Board considered Fidelity's staffing as it relates to the funds, including the backgrounds of investment personnel of Fidelity, and also considered the funds' investment objectives, strategies, and related investment philosophies. The Independent Trustees also had discussions with senior management of Fidelity's investment operations and investment groups. The Board considered the structure of the investment personnel compensation program and whether this structure provides appropriate incentives to act in the best interests of each fund. Additionally, the Board considered the portfolio managers' investments, if any, in the funds that they manage.

Shareholder and Administrative Services. The Board considered (i) the nature, extent, quality, and cost of advisory, administrative, and shareholder services performed by the Investment Advisers and their affiliates under the Advisory Contracts and under separate agreements covering transfer agency, pricing and bookkeeping, and securities lending services for each fund; (ii) the nature and extent of the supervision of third party service providers, principally custodians, subcustodians, and pricing vendors; and (iii) the resources devoted to, and the record of compliance with, each fund's compliance policies and procedures.

Investment Performance. The Board considered whether each fund has operated in accordance with its investment objective, as well as its record of compliance with its investment restrictions and its performance history.

The Board took into account discussions that occur at Board meetings throughout the year with representatives of the Investment Advisers about fund investment performance. In this regard the Board noted that as part of regularly scheduled fund reviews and other reports to the Board on fund performance, the Board considers annualized return information for each fund for different time periods, measured against the securities market index the fund seeks to track and a peer group of funds with similar objectives ("peer group"), if any. The Board also periodically considers each fund's tracking error versus its benchmark index. In its evaluation of fund investment performance at meetings throughout the year, the Board gave particular attention to information indicating underperformance of certain Fidelity funds for specific time periods and discussed with the Investment Advisers the reasons for such underperformance.

The Independent Trustees recognize that shareholders evaluate performance on a net basis (after fees and expenses) over their own holding periods, for which one-, three-, and five-year periods are often used as a proxy. For this reason, the performance information reviewed by the Board also included net cumulative calendar year total return information for each fund and its benchmark index and peer group for the most recent one-, three-, and five-year periods.

Based on its review, the Board concluded that the nature, extent, and quality of services provided to each fund under the Advisory Contracts should continue to benefit the shareholders of each fund.

Competitiveness of Management Fee and Total Expense Ratio. The Board considered each fund's management fee and total expense ratio compared to "mapped groups" of competitive funds and classes created for the purpose of facilitating the Trustees' competitive analysis of management fees and total expenses. Fidelity creates "mapped groups" by combining similar Lipper investment objective categories that have comparable investment mandates. Combining Lipper investment objective categories aids the Board's management fee and total expense ratio comparisons by broadening the competitive group used for comparison.

Management Fee. The Board considered two proprietary management fee comparisons for the 12-month periods shown in basis points (BP) in the charts below. The group of Lipper funds used by the Board for management fee comparisons is referred to below as the "Total Mapped Group" and, for the reasons explained above, is broader than the Lipper peer group used by the Board for performance comparisons. The Total Mapped Group comparison focuses on a fund's standing in terms of gross management fees before expense reimbursements or caps relative to the total universe of funds with comparable investment mandates, regardless of whether their management fee structures also are comparable. Funds with comparable investment mandates offer exposure to similar types of securities. Funds with comparable management fee structures have similar management fee contractual arrangements (e.g., flat rate charged for advisory services, all-inclusive fee rate, etc.). "TMG %" represents the percentage of funds in the Total Mapped Group that had management fees that were lower than a fund's. For example, a hypothetical TMG % of 20% would mean that 80% of the funds in the Total Mapped Group had higher, and 20% had lower, management fees than a fund. The funds' actual TMG %s and the number of funds in the Total Mapped Group are in the charts below. The "Asset-Size Peer Group" (ASPG) comparison focuses on a fund's standing relative to a subset of non-Fidelity funds within the Total Mapped Group that are similar in size and management fee structure. For example, if a fund is in the first quartile of the ASPG, the fund's management fee ranks in the least expensive or lowest 25% of funds in the ASPG. The ASPG represents at least 15% of the funds in the Total Mapped Group with comparable asset size and management fee structures, subject to a minimum of 50 funds (or all funds in the Total Mapped Group if fewer than 50). Additional information, such as the ASPG quartile in which a fund's management fee rate ranked, is also included in the charts and was considered by the Board. Because the vast majority of competitor funds' management fees do not cover non-management expenses, in prior years, each fund was compared on the basis of a hypothetical "net management fee," which was derived by subtracting payments made by FMR for "fund-level" non-management expenses (including pricing and bookkeeping fees and fees paid to non-affiliated custodians), as well as "class-level" expenses paid by FMR under expense limitation arrangements in effect for the fund, from the fund's management fee. Fidelity no longer calculates hypothetical net management fees for the funds and, as a result, the charts do not include hypothetical net management fees for 2016 and 2017. With respect to the historical net management fee information, the Board considered that "fund-level" non-management expenses and "class-level" expenses paid by FMR may exceed a fund's management fee and result in a negative net management fee. The Board noted that a hypothetical net management fee is truly a hypothetical number derived for purposes of providing a more meaningful competitive comparison and a negative net management fee is not intended to suggest that Fidelity pays a fund to manage the fund's assets.

Fidelity Intermediate Treasury Bond Index Fund

The Board considered that effective August 1, 2017, the fund’s management fee rate was reduced from 0.05% to 0.03%. The Board considered that the chart below reflects the fund’s lower management fee rate for 2017, as if the lower fee rate were in effect for the entire year.

The Board noted that the fund's management fee rate ranked below the median of its Total Mapped Group and below the median of its ASPG for 2017.

Fidelity Long-Term Treasury Bond Index Fund

The Board noted that the fund’s management fee rate ranked below the median of its Total Mapped Group and below the median of its ASPG for 2017.

Fidelity Short-Term Treasury Bond Index Fund

The Board noted that the fund’s management fee rate ranked below the median of its Total Mapped Group and below the median of its ASPG for 2017.

The Board noted that it and the boards of other Fidelity funds formed an ad hoc Committee on Group Fee, which meets periodically, to conduct an in-depth review of the "group fee" component of the management fee of funds with such management fee structures. The Committee's focus included the mechanics of the group fee, the competitive landscape of group fee structures, Fidelity funds with no group fee component (such as the funds) and investment products not included in group fee assets. The Board also considered that, for funds subject to the group fee, FMR agreed to voluntarily waive fees over a specified period of time in amounts designed to account for assets converted from certain funds to certain collective investment trusts.

Based on its review, the Board concluded that each fund's management fee is fair and reasonable in light of the services that the fund receives and the other factors considered.

Total Expense Ratio. In its review of the total expense ratio of each class of each fund, the Board considered the fund's management fee rate as well as other "fund-level" expenses, such as pricing and bookkeeping fees and custodial, legal, and audit fees, paid by FMR under the fund's management contract. The Board also considered other "class-level" expenses, such as transfer agent fees. The Board also noted that Fidelity may agree to waive fees and expenses from time to time, and the extent to which, if any, it has done so for each fund. As part of its review, the Board also considered the current and historical total expense ratios of each class of each fund compared to competitive fund median expenses. Each class of each fund is compared to those funds and classes in the Total Mapped Group (used by the Board for management fee comparisons) that have a similar sales load structure.

The Board noted that the total expense ratio of each of Premium Class, Institutional Class, and Institutional Premium Class of each fund ranked below the competitive median for 2017 and the total expense ratio of Investor Class of each fund ranked above the competitive median for 2017 due to a drop in the competitive median, compared to the prior year, as a result of competitor fee reductions and the inclusion of lower fee Fidelity and competitor classes in the mapped group. The Board considered that, in general, various factors can affect total expense ratios.

At its July 2018 meeting, the Board approved a proposal for each fund to consolidate all classes into a single class by exchanging all shares of higher cost classes for shares of the lowest cost class available. The exchanges are expected to take place in November 2018. In connection with the class consolidation, the Board approved amended and restated expense contracts that reduce the total expense ratio of each class of each fund to equal the total expense ratio of the lowest cost class. The Board considered that, effective August 1, 2018, contractual arrangements for each fund oblige FMR to pay all "class-level" expenses of each class of the fund to the extent necessary to limit total class operating expenses, with certain exceptions, to 0.03%. These contractual arrangements may not be amended to increase the fees or expenses payable except by a vote of a majority of the Board.

Based on its review of total expense ratios and fees charged to other Fidelity clients, the Board concluded that the total expense ratio of each class of each fund was reasonable in light of the services that the fund and its shareholders receive and the other factors considered.

Costs of the Services and Profitability. The Board consideredthe revenues earned and the expenses incurred by Fidelity in conducting the business of developing, marketing, distributing, managing, administering and servicing each fund and servicing each fund's shareholders. The Board also considered the level of Fidelity's profits in respect of all the Fidelity funds.

On an annual basis, Fidelity presents to the Board information about the profitability of its relationships with each fund. Fidelity calculates profitability information for each fund, as well as aggregate profitability information for groups of Fidelity funds and all Fidelity funds, using a series of detailed revenue and cost allocation methodologies which originate with the books and records of Fidelity on which Fidelity's audited financial statements are based. The Audit Committee of the Board reviews any significant changes from the prior year's methodologies.

The Board also reviewed Fidelity's non-fund businesses and potential indirect benefits such businesses may have received as a result of their association with Fidelity's mutual fund business (i.e., fall-out benefits) as well as cases where Fidelity's affiliates may benefit from the funds' business. The Board noted that changes to fall-out benefits year-over-year reflect business developments at Fidelity's various businesses.

The Board considered the costs of the services provided by and the profits realized by Fidelity in connection with the operation of each fund and was satisfied that the profitability was not excessive.

Economies of Scale. The Board considered whether there have been economies of scale in respect of the management of the Fidelity funds, whether the Fidelity funds (including each fund) have appropriately benefited from any such economies of scale, and whether there is potential for realization of any further economies of scale. The Board considered the extent to which each fund will benefit from economies of scale as assets grow through increased services to the fund, through waivers or reimbursements, or through fee or expense ratio reductions. The Board recognized that, due to each fund's current contractual arrangements, the expense ratio of each class will not decline if the class's operating costs decrease as assets grow, or rise as assets decrease. The Board also noted that a committee (the Economies of Scale Committee) created by it and the boards of other Fidelity funds periodically analyzes whether Fidelity attains economies of scale in respect of the management and servicing of the Fidelity funds, whether the Fidelity funds have appropriately benefited from such economies of scale, and whether there is potential for realization of any further economies of scale.

The Board concluded, taking into account the analysis of the Economies of Scale Committee, that economies of scale, if any, are being appropriately shared between fund shareholders and Fidelity.

Fidelity Investments

LBX-I-ANN-0419
1.9885078.101

Item 2.

Code of Ethics

As of the end of the period, February 28, 2019, Fidelity Salem Street Trust (the trust) has adopted a code of ethics, as defined in Item 2 of Form N-CSR, that applies to its President and Treasurer and its Chief Financial Officer. A copy of the code of ethics is filed as an exhibit to this Form N-CSR.

Item 3.

Audit Committee Financial Expert

The Board of Trustees of the trust has determined that Elizabeth S. Acton is an audit committee financial expert, as defined in Item 3 of Form N-CSR. Ms. Acton is independent for purposes of Item 3 of Form N-CSR.

Item 4.

Principal Accountant Fees and Services

Fees and Services

The following table presents fees billed by Deloitte & Touche LLP, the member firms of Deloitte Touche Tohmatsu, and their respective affiliates (collectively, “Deloitte Entities”) in each of the last two fiscal years for services rendered to Fidelity SAI Long-Term Treasury Bond Index Fund and Fidelity SAI U.S. Treasury Bond Index Fund (the “Funds”):

Services Billed by Deloitte Entities

February 28, 2019 Fees^A


	Audit Fees	Audit-Related Fees	Tax Fees	All Other Fees
Fidelity SAI Long-Term Treasury Bond Index Fund	$43,000	$100	$6,300	$1,300
Fidelity SAI U.S. Treasury Bond Index Fund	$48,000	$100	$5,100	$1,400

February 28, 2018 Fees^A


	Audit Fees	Audit-Related Fees	Tax Fees	All Other Fees
Fidelity SAI Long-Term Treasury Bond Index Fund	$44,000	$100	$6,300	$1,300
Fidelity SAI U.S. Treasury Bond Index Fund	$49,000	$100	$5,100	$1,100

^AAmounts may reflect rounding.

The following table presents fees billed by PricewaterhouseCoopers LLP (“PwC”) in each of the last two fiscal years for services rendered to Fidelity Intermediate Treasury Bond Index Fund, Fidelity Long-Term Treasury Bond Index Fund, Fidelity Series Long-Term Treasury Bond Index Fund and Fidelity Short-Term Treasury Bond Index Fund (the “Funds”):

Services Billed by PwC

February 28, 2019 Fees^A


	Audit Fees	Audit-Related Fees	Tax Fees	All Other Fees
Fidelity Intermediate Treasury Bond Index Fund	$46,000	$4,300	$3,300	$2,500
Fidelity Long-Term Treasury Bond Index Fund	$46,000	$4,300	$3,300	$2,500
Fidelity Series Long-Term Treasury Bond Index Fund	$48,000	$4,200	$3,900	$2,400
Fidelity Short-Term Treasury Bond Index Fund	$46,000	$4,300	$3,300	$2,500

February 28, 2018 Fees^A


	Audit Fees	Audit-Related Fees	Tax Fees	All Other Fees
Fidelity Intermediate Treasury Bond Index Fund	$52,000	$6,100	$3,300	$3,200
Fidelity Long-Term Treasury Bond Index Fund	$52,000	$6,100	$3,300	$3,200
Fidelity Series Long-Term Treasury Bond Index Fund	$48,000	$4,000	$3,900	$2,100
Fidelity Short-Term Treasury Bond Index Fund	$52,000	$6,100	$3,300	$3,200

^AAmounts may reflect rounding

The following table presents fees billed by PwC and Deloitte Entities that were required to be approved by the Audit Committee for services that relate directly to the operations and financial reporting of the Funds and that are rendered on behalf of Fidelity Management & Research Company (“FMR”) and entities controlling, controlled by, or under common control with FMR (not including any sub-adviser whose role is primarily portfolio management and is subcontracted with or overseen by another investment adviser) that provide ongoing services to the Funds (“Fund Service Providers”):

Services Billed by Deloitte Entities


	February 28, 2019^A	February 28, 2018^A
Audit-Related Fees	$290,000	$5,000
Tax Fees	$5,000	$20,000
All Other Fees	$-	$-

^A Amounts may reflect rounding.

Services Billed by PwC


	February 28, 2019^A	February 28, 2018^A
Audit-Related Fees	$7,930,000	$8,360,000
Tax Fees	$15,000	$30,000
All Other Fees	$-	$-

^A Amounts may reflect rounding.

“Audit-Related Fees” represent fees billed for assurance and related services that are reasonably related to the performance of the fund audit or the review of the fund's financial statements and that are not reported under Audit Fees.

“Tax Fees” represent fees billed for tax compliance, tax advice or tax planning that relate directly to the operations and financial reporting of the fund.

“All Other Fees” represent fees billed for services provided to the fund or Fund Service Provider, a significant portion of which are assurance related, that relate directly to the operations and financial reporting of the fund, excluding those services that are reported under Audit Fees, Audit-Related Fees or Tax Fees.

Assurance services must be performed by an independent public accountant.

* * *

The aggregate non-audit fees billed by PwC and Deloitte Entities for services rendered to the Funds, FMR (not including any sub-adviser whose role is primarily portfolio management and is subcontracted with or overseen by another investment adviser), and any Fund Service Provider for each of the last two fiscal years of the Funds are as follows:


Billed By	February 28, 2019^A	February 28, 2018^A
Deloitte Entities	$770,000	$295,000
PwC	$11,160,000	$10,790,000

^A Amounts may reflect rounding.

The trust's Audit Committee has considered non-audit services that were not pre-approved that were provided by PwC and Deloitte Entities to Fund Service Providers to be compatible with maintaining the independence of PwC and Deloitte Entities in their audits of the Funds, taking into account representations from PwC and Deloitte Entities, in accordance with Public Company Accounting Oversight Board rules, regarding their independence from the Funds and their related entities and FMR’s review of the appropriateness and permissibility under applicable law of such non-audit services prior to their provision to the Fund Service Providers.

Audit Committee Pre-Approval Policies and Procedures

The trust’s Audit Committee must pre-approve all audit and non-audit services provided by a fund’s independent registered public accounting firm relating to the operations or financial reporting of the fund. Prior to the commencement of any audit or non-audit services to a fund, the Audit Committee reviews the services to determine whether they are appropriate and permissible under applicable law.

The Audit Committee has adopted policies and procedures to, among other purposes, provide a framework for the Committee’s consideration of non-audit services by the audit firms that audit the Fidelity funds. The policies and procedures require that any non-audit service provided by a fund audit firm to a Fidelity fund and any non-audit service provided by a fund auditor to a Fund Service Provider that relates directly to the operations and financial reporting of a Fidelity fund (“Covered Service”) are subject to approval by the Audit Committee before such service is provided.

All Covered Services must be approved in advance of provision of the service either: (i) by formal resolution of the Audit Committee, or (ii) by oral or written approval of the service by the Chair of the Audit Committee (or if the Chair is unavailable, such other member of the Audit Committee as may be designated by the Chair to act in the Chair’s absence). The approval contemplated by (ii) above is permitted where the Treasurer determines that action on such an engagement is necessary before the next meeting of the Audit Committee.

Non-audit services provided by a fund audit firm to a Fund Service Provider that do not relate directly to the operations and financial reporting of a Fidelity fund are reported to the Audit Committee periodically.

Non-Audit Services Approved Pursuant to Rule 2-01(c)(7)(i)(C) and (ii) of Regulation S-X (“De Minimis Exception”)

There were no non-audit services approved or required to be approved by the Audit Committee pursuant to the De Minimis Exception during the Funds’ last two fiscal years relating to services provided to (i) the Funds or (ii) any Fund Service Provider that relate directly to the operations and financial reporting of the Funds.

Item 5.

Audit Committee of Listed Registrants

Not applicable.

Item 6.

Investments

(a)

Not applicable.

(b)

Not applicable

Item 7.

Disclosure of Proxy Voting Policies and Procedures for Closed-End Management Investment Companies

Not applicable.

Item 8.

Portfolio Managers of Closed-End Management Investment Companies

Not applicable.

Item 9.

Purchase of Equity Securities by Closed-End Management Investment Company and Affiliated Purchasers

Not applicable.

Item 10.

Submission of Matters to a Vote of Security Holders

There were no material changes to the procedures by which shareholders may recommend nominees to the trust’s Board of Trustees.

Item 11.

Controls and Procedures

(a)(i) The President and Treasurer and the Chief Financial Officer have concluded that the trust’s disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act) provide reasonable assurances that material information relating to the trust is made known to them by the appropriate persons, based on their evaluation of these controls and procedures as of a date within 90 days of the filing date of this report.

(a)(ii) There was no change in the trust’s internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act) that occurred during the period covered by this report that has materially affected, or is reasonably likely to materially affect, the trust’s internal control over financial reporting.

Item 12.

Disclosure of Securities Lending Activities for Closed-End Management

Investment Companies

Not applicable.

Item 13.

Exhibits


(a)	(1)	Code of Ethics pursuant to Item 2 of Form N-CSR is filed and attached hereto as EX-99.CODE ETH.
(a)	(2)	Certification pursuant to Rule 30a-2(a) under the Investment Company Act of 1940 (17 CFR 270.30a-2(a)) is filed and attached hereto as Exhibit 99.CERT.
(a)	(3)	Not applicable.
(b)		Certification pursuant to Rule 30a-2(b) under the Investment Company Act of 1940 (17 CFR 270.30a-2(b)) is furnished and attached hereto as Exhibit 99.906CERT.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Fidelity Salem Street Trust


By:	/s/Laura M. Del Prato
	Laura M. Del Prato
	President and Treasurer

Date:	April 24, 2019

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.


By:	/s/Laura M. Del Prato
	Laura M. Del Prato
	President and Treasurer

Date:	April 24, 2019


By:	/s/John J. Burke III
	John J. Burke III
	Chief Financial Officer

Date:	April 24, 2019

Fidelity SAI Municipal Income (FSMNX) N-CSRCertified annual shareholder report (management investment company)