MFS Institutional Money Market Portfolio, A Series Of The MFS Series Trust Xiv N-CSR 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 811-22033

MFS SERIES TRUST XIV

(Exact name of registrant as specified in charter)

500 Boylston Street, Boston, Massachusetts 02116

(Address of principal executive offices) (Zip code)

Susan S. Newton

Massachusetts Financial Services Company

500 Boylston Street

Boston, Massachusetts 02116

(Name and address of agents for service)

Registrant’s telephone number, including area code: (617) 954-5000

Date of fiscal year end: August 31

Date of reporting period: August 31, 2012

ITEM 1. REPORTS TO STOCKHOLDERS.

ANNUAL REPORT

August 31, 2012

MFS® INSTITUTIONAL MONEY MARKET PORTFOLIO

IMM-ANN

MFS® INSTITUTIONAL MONEY MARKET PORTFOLIO

CONTENTS

Letter from the Chairman and CEO	1
Portfolio composition	2
Performance summary	3
Expense table	4
Portfolio of investments	5
Statement of assets and liabilities	9
Statement of operations	10
Statements of changes in net assets	11
Financial highlights	12
Notes to financial statements	13
Report of independent registered public accounting firm	17
Trustees and officers	18
Board review of investment advisory agreement	23
Proxy voting policies and information	26
Quarterly portfolio disclosure	26
Further information	26
Federal tax information	26
MFS® privacy notice	27
Contact information    back cover

The report is prepared for the general information of shareholders.

It is authorized for distribution to prospective investors only when preceded or accompanied by a current prospectus.

NOT FDIC INSURED Ÿ MAY LOSE VALUE Ÿ NO BANK GUARANTEE

LETTER FROM THE CHAIRMAN AND CEO

Dear Shareholders:

World financial markets continue to face a number of major economic and political challenges. While the European debt crisis has deepened and spread, there appears to be scope for improvement given the European Central Bank’s willingness to backstop troubled sovereigns. Economic activity in China, until recently the world’s growth engine, appears to be bottoming. Even the relatively strong and stable US

economy has been affected by uncertainty over the presidential election and the threat of a “fiscal cliff” at year- end. At the same time, global consumer and producer confidence has fallen sharply. And a search for safe havens by nervous investors has driven down yields on highly rated government bonds, including those issued by Germany and the United States, to multi-decade lows.

But there is also good news: Global economic data have modestly improved, performing slightly better than expected. However, the improvement is too short-lived to be called a trend. Equity markets have been largely range bound since the

Fed extended its quantitative easing program, leaving little expectation that the bank will add further money to the system. It is hard to know how much of the recent gain in financial markets has been the result of actual economic improvements versus expectations that renewed central bank action will soon lead to an economic rebound.

Through all this uncertainty, managing risk remains a top priority for investors and their advisors. At MFS®, our emphasis on global research is designed to keep our investment process functioning smoothly at all times. Close collaboration among colleagues around the world is vital in periods of uncertainty and heightened volatility. We share ideas and evaluate opportunities across continents and across all investment disciplines and types of investments. We employ this uniquely collaborative approach to build better insights — and better results — for our clients.

Like our investors, we are mindful of the many economic challenges we face at the local, national and international levels. In times like these, it is more important than ever to maintain a long-term view, adhere to time-tested investing principles such as asset allocation and diversification and work closely with investment advisors to research and identify the most suitable opportunities.

Respectfully,

Robert J. Manning

Chairman and Chief Executive Officer

MFS Investment Management®

October 17, 2012

The opinions expressed in this letter are subject to change, may not be relied upon for investment advice and no forecasts can be guaranteed.

1

PORTFOLIO COMPOSITION

Portfolio structure (u)

Composition including fixed income credit quality (a)(u)
A-1+	15.0%
A-1	78.3%
A-2	6.6%
Not Rated	0.0%
Cash & Other	0.1%

Maturity breakdown (u)
0 - 7 days	27.1%
8 - 29 days	34.7%
30 - 59 days	23.2%
60 - 89 days	9.5%
90 - 365 days	5.4%
Other Assets Less Liabilities	0.1%

(a) Ratings are assigned to portfolio securities utilizing ratings from Moody’s, Fitch, and Standard & Poor’s rating agencies and applying the following hierarchy: If all three agencies provide a rating, the middle rating (after dropping the highest and lowest ratings) is assigned; if two of the three agencies rate a security, the lower of the two is assigned. Cash & Other portfolio assets that are not securities are not included in the categories mentioned above. Ratings are shown in the S&P scale. All ratings are subject to change. The fund is not rated by these agencies.

(u) For purposes of this presentation, accrued interest, where applicable, is included.

Percentages are based on net assets as of 8/31/12.

The portfolio is actively managed and current holdings may be different.

2

PERFORMANCE SUMMARY THROUGH 8/31/12

Total returns as well as the current 7-day yield have been provided for the applicable time periods. Performance results reflect the percentage change in net asset value, including the reinvestment of any dividends and capital gains distributions. (See Notes to Performance Summary.)

Performance data shown represents past performance and is no guarantee of future results. Although the fund seeks to preserve the value of your investment at $1.00 per share, you could lose money on your investment in the fund. An investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. The performance shown does not reflect the deduction of taxes, if any, that a shareholder would pay on fund distributions or the redemption of fund shares.

Inception	1-Year Total Return (without Sales charge)	Current 7-day yield
3/19/07	0.11%	0.16%

Yields quoted are based on the latest seven days ended as of August 31, 2012, with dividend annualized. The yield quotations more closely reflect the current earnings of the fund than the total return quotations. Shares of the fund can be purchased at net asset value without a sales charge.

Notes to Performance Summary

Performance results reflect any applicable expense subsidies, waivers and adjustments in effect during the periods shown. Subsidies and fee waivers may be imposed to enhance a fund’s yield or to avoid a negative yield during periods when the fund’s operating expenses have a significant impact on the fund’s yield due to lower interest rates. Without such subsidies and waivers the fund’s performance results would be less favorable. Please see the prospectus and financial statements for complete details. All results are historical and assume the reinvestment of any dividends and capital gain distributions.

3

EXPENSE TABLE

Fund expenses borne by the shareholders during the period,

March 1, 2012 through August 31, 2012

As a shareholder of the fund you incur 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 March 1, 2012 through August 31, 2012.

Actual Expenses

The first line of the following 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 (for example, an $8,600 account value divided by $1,000 = 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.

Hypothetical Example for Comparison Purposes

The second line of the following 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.

Please note that the expenses shown in the table are meant to highlight your ongoing costs only and do not reflect any transactional costs, such as sales charges (loads). 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. In addition, if these transactional costs were included, your costs would have been higher.

Share Class		Annualized Expense Ratio	Beginning Account Value 3/01/12	Ending Account Value 8/31/12	Expenses Paid During Period (p) 3/01/12-8/31/12
	Actual	0.01%	$1,000.00	$1,000.67		$0.05
	Hypothetical (h)	0.01%	$1,000.00	$1,025.09		$0.05

(h) 5% class return per year before expenses.

(p) Expenses paid are equal to each class’ annualized expense ratio, as shown above, multiplied by the average account value over the period, multiplied by the number of days in the period, divided by the number of days in the year. Expenses paid do not include any applicable sales charges (loads). If these transaction costs had been included, your costs would have been higher.

4

PORTFOLIO OF INVESTMENTS

8/31/12

The Portfolio of Investments is a complete list of all securities owned by your fund. It is categorized by broad-based asset classes.

Certificates of Deposit - 20.8%
Issuer	Shares/Par		Value ($)
Major Banks - 11.0%
Bank of Montreal/Chicago Branch, 0.16%, due 9/24/12	$	92,370,000	$	92,370,000
Bank of Montreal/Chicago Branch, 0.17%, due 9/13/12		38,380,000		38,380,000
Bank of Montreal/Chicago Branch, 0.19%, due 9/13/12		1,520,000		1,520,000
Chase Bank USA N.A., 0.18%, due 9/13/12		18,000,000		18,000,000
National Australia Bank/New York Branch, 0.27%, due 2/19/13		17,050,000		17,050,000
Toronto Dominion Holdings (USA), Inc., 0.16%, due 10/26/12		94,630,000		94,630,000
Westpac Banking Corp./New York Branch, 0.25%, due 9/17/12		88,935,000		88,935,000
			$	350,885,000
Other Banks & Diversified Financials - 9.8%
Bank of Nova Scotia/Houston Branch, 0.27%, due 2/01/13	$	50,000,000	$	50,000,000
Branch Banking & Trust Co., 0.28%, due 11/16/12		106,190,000		106,190,000
Branch Banking & Trust Co., 0.28%, due 11/20/12		25,000,000		25,000,000
Mizuho Corporate Bank (USA)/New York Branch, 0.18%, due 9/24/12		22,990,000		22,990,000
Mizuho Corporate Bank (USA)/New York Branch, 0.34%, due 11/21/12		50,000,000		50,000,000
Mizuho Corporate Bank (USA)/New York Branch, 0.36%, due 9/18/12		16,380,000		16,380,000
Mizuho Corporate Bank (USA)/New York Branch, 0.36%, due 10/17/12		42,880,000		42,880,000
			$	313,440,000
Total Certificates of Deposit, at Cost and Value			$	664,325,000
Commercial Paper (y) - 49.5%
Automotive - 5.0%
American Honda Finance Corp., 0.12%, due 9/11/12	$	25,000,000	$	24,999,167
Toyota Motor Credit Corp., 0.15%, due 10/02/12		81,000,000		80,989,537
Toyota Motor Credit Corp., 0.17%, due 10/29/12		43,809,000		43,797,001
Toyota Motor Credit Corp., 0.23%, due 1/28/13		8,357,000		8,349,045
			$	158,134,750
Conglomerates - 7.0%
Siemens Capital Corp., 0.11%, due 9/04/12 (t)	$	22,600,000	$	22,599,793
Siemens Capital Corp., 0.17%, due 9/17/12 (t)		65,038,000		65,033,086
United Technologies Corp., 0.12%, due 9/26/12 (t)		36,000,000		35,997,000
United Technologies Corp., 0.12%, due 9/28/12 (t)		28,290,000		28,287,454
United Technologies Corp., 0.14%, due 9/24/12 (t)		45,251,000		45,246,952

5

Portfolio of Investments – continued

Issuer	Shares/Par		Value ($)
Commercial Paper (y) - continued
Conglomerates - continued
United Technologies Corp., 0.2%, due 9/24/12 (t)	$	23,041,000	$	23,038,056
United Technologies Corp., 0.21%, due 10/18/12 (t)		2,766,000		2,765,242
			$	222,967,583
Electrical Equipment - 2.3%
General Electric Co., 0.15%, due 9/04/12	$	72,481,000	$	72,480,094
Electronics - 1.0%
Emerson Electric Co., 0.12%, due 10/29/12 (t)	$	30,000,000	$	29,994,200
Financial Institutions - 1.7%
General Electric Capital Corp., 0.17%, due 9/24/12	$	25,574,000	$	25,571,222
General Electric Capital Corp., 0.23%, due 12/14/12		28,466,000		28,447,086
			$	54,018,308
Food & Beverages - 8.5%
Anheuser-Busch InBev S.A., 0.22%, due 9/20/12 (t)	$	4,371,000	$	4,370,492
Anheuser-Busch InBev S.A., 0.22%, due 10/05/12 (t)		15,789,000		15,785,719
Anheuser-Busch InBev S.A., 0.25%, due 10/26/12 (t)		2,880,000		2,878,900
Anheuser-Busch InBev S.A., 0.25%, due 10/29/12 (t)		39,405,000		39,389,128
Anheuser-Busch InBev S.A., 0.35%, due 11/26/12 (t)		26,395,000		26,372,931
Anheuser-Busch InBev S.A., 0.35%, due 11/27/12 (t)		23,485,000		23,465,136
Coca-Cola Co., 0.21%, due 9/04/12 (t)		28,019,000		28,018,510
Coca-Cola Co., 0.22%, due 11/19/12 (t)		19,400,000		19,390,634
Coca-Cola Co., 0.23%, due 10/05/12 (t)		33,792,000		33,784,660
Coca-Cola Co., 0.23%, due 10/09/12 (t)		28,098,000		28,091,178
Coca-Cola Co., 0.24%, due 10/15/12 (t)		23,848,000		23,841,004
Coca-Cola Co., 0.25%, due 10/15/12 (t)		1,500,000		1,499,542
Pepsico, Inc., 0.13%, due 9/10/12 (t)		24,931,000		24,930,190
			$	271,818,024
Machinery & Tools - 0.1%
Deere and Co., 0.14%, due 9/20/12 (t)	$	2,171,000	$	2,170,840
Major Banks - 10.2%
ANZ National (International) Ltd., 0.35%, due 1/25/13 (t)	$	17,910,000	$	17,884,578
Bank of Nova Scotia, 0.14%, due 9/06/12		85,774,000		85,772,392
JPMorgan Chase & Co., 0.25%, due 10/16/12		128,746,000		128,705,767
National Australia Funding (Delaware), Inc., 0.28%, due 2/19/13 (t)		50,000,000		49,933,500
Wells Fargo & Co., 0.16%, due 11/19/12		25,800,000		25,790,941
Wells Fargo & Co., 0.16%, due 11/20/12		17,704,000		17,697,705
			$	325,784,883

6

Portfolio of Investments – continued

Issuer	Shares/Par		Value ($)
Commercial Paper (y) - continued
Pharmaceuticals - 7.3%
Novartis Finance Corp., 0.13%, due 9/05/12 (t)	$	86,752,000	$	86,750,747
Novartis Finance Corp., 0.14%, due 9/10/12 (t)		40,000,000		39,998,600
Sanofi, 0.15%, due 9/26/12 (t)		107,231,000		107,219,830
			$	233,969,177
Retailers - 4.1%
Wal-Mart Stores, Inc., 0.1%, due 9/10/12 (t)	$	61,119,000	$	61,117,472
Wal-Mart Stores, Inc., 0.13%, due 9/04/12 (t)		70,000,000		69,999,242
			$	131,116,714
Tobacco - 2.3%
Philip Morris International, Inc., 0.16%, due 9/05/12 (t)	$	47,730,000	$	47,729,151
Philip Morris International, Inc., 0.17%, due 9/27/12 (t)		26,250,000		26,246,777
			$	73,975,928
Total Commercial Paper, at Amortized Cost and Value			$	1,576,430,501
U.S. Government Agencies and Equivalents (y) - 15.5%
Fannie Mae, 0.09%, due 10/01/12	$	50,000,000	$	49,996,250
Federal Home Loan Bank, 0.11%, due 9/25/12		23,386,000		23,384,363
Federal Home Loan Bank, 0.11%, due 10/17/12		122,159,000		122,141,830
Federal Home Loan Bank, 0.12%, due 9/21/12		125,000,000		124,991,667
Federal Home Loan Bank, 0.15%, due 11/16/12		10,006,000		10,002,937
Federal Home Loan Mortgage Corp., 0.11%, due 9/27/12		53,300,000		53,295,958
Freddie Mac, 0%, due 9/11/12		10,525,000		10,524,649
Freddie Mac, 0.16%, due 9/24/12		50,000,000		49,995,049
Tennessee Valley Authority, 0.11%, due 9/20/12		50,000,000		49,997,229
Total U.S. Government Agencies and Equivalents, at Amortized Cost and Value			$	494,329,932
Floating Rate Demand Notes - 2.0%
Industrial Revenue - Other - 2.0%
Lincoln County, WY, Pollution Control Rev. (Exxon Mobil Corp.), “A”, 0.16%, due 9/04/12	$	16,500,000	$	16,500,000
Lincoln County, WY, Pollution Control Rev. (Exxon Mobil Corp.), “B”, 0.16%, due 9/04/12		6,600,000		6,600,000
Lincoln County, WY, Pollution Control Rev. (Exxon Mobil Corp.), “C”, 0.16%, due 9/04/12		17,900,000		17,900,000
Sublette County, WY, Pollution Control Rev. (Exxon Mobil Corp.), 0.16%, due 9/04/12		23,500,000		23,500,000
Total Floating Rate Demand Notes, at Cost and Value			$	64,500,000

7

Portfolio of Investments – continued

Repurchase Agreements - 12.1%
Issuer	Shares/Par		Value ($)
Goldman Sachs Group, Inc., 0.18%, dated 8/31/12, due 9/04/12, total to be received $211,639,175 (secured by Federal Agency obligations valued at $215,868,361 in an individually traded account)	$	211,635,000	$	211,635,000
Merrill Lynch, Pierce Fenner & Smith, Inc. , 0.18%, dated 8/31/12, due 9/04/12, total to be received $174,648,861 (secured by U.S. Treasury obligations valued at $178,141,008 in an individually traded account)		174,648,000		174,648,000
Total Repurchase Agreements, at Cost and Value			$	386,283,000
Total Investments, at Amortized Cost and Value			$	3,185,868,433
Other Assets, Less Liabilities - 0.1%				3,103,078
Net Assets - 100.0%			$	3,188,971,511

(t) Security exempt from registration with the U.S. Securities and Exchange Commission under Section 4(2) of the Securities Act of 1933.

(y) The rate shown represents an annualized yield at time of purchase.

See Notes to Financial Statements

8

Financial Statements

STATEMENT OF ASSETS AND LIABILITIES

At 8/31/12

This statement represents your fund’s balance sheet, which details the assets and liabilities comprising the total value of the fund.

Assets
Investments, at amortized cost and value	$2,799,585,433
Repurchase agreements, at cost and value	386,283,000
Total investments, at amortized cost and value	$3,185,868,433
Cash	3,020,380
Interest receivables	163,248
Other assets	5,622
Total assets	$3,189,057,683
Liabilities
Payable to affiliate for shareholder servicing costs	$197
Accrued expenses and other liabilities	85,975
Total liabilities	$86,172
Net assets	$3,188,971,511
Net assets consist of
Paid-in capital	$3,189,152,729
Accumulated net realized gain (loss) on investments	(181,218	)
Net assets	$3,188,971,511
Shares of beneficial interest outstanding	3,189,153,007
Net asset value per share (net assets of $3,188,971,511 / 3,189,153,007 shares of beneficial interest outstanding)	$1.00

See Notes to Financial Statements

9

Financial Statements

STATEMENT OF OPERATIONS

Year ended 8/31/12

This statement describes how much your fund earned in investment income and accrued in expenses. It also describes any gains and/or losses generated by fund operations.

Net investment income
Interest income	$3,429,976
Expenses
Shareholder servicing costs	$910
Insurance fee	31,790
Independent chief compliance officer fee	23,663
Custodian fee	156,309
Shareholder communications	7,686
Audit and tax fees	29,293
Legal fees	40,456
Commitment fee	18,886
Miscellaneous	9,735
Total expenses	$318,728
Fees paid indirectly	(176	)
Reduction of expenses by investment adviser	(10,698	)
Net expenses	$307,854
Net investment income	$3,122,122
Change in net assets from operations	$3,122,122

See Notes to Financial Statements

10

Financial Statements

STATEMENTS OF CHANGES IN NET ASSETS

These statements describe the increases and/or decreases in net assets resulting from operations, any distributions, and any shareholder transactions.

	Years ended 8/31
	2012			2011
Change in net assets
From operations
Net investment income		$3,122,122			$3,830,451
Net realized gain (loss) on investments		—			3,630
Change in net assets from operations		$3,122,122			$3,834,081
Distributions declared to shareholders
From net investment income		$(3,122,122	)		$(3,830,451	)
Fund share (principal) transactions at net asset value of $1 per share
Net proceeds from sale of shares		29,057,598,328			26,379,681,849
Net asset value of shares issued to shareholders in reinvestment of distributions		3,122,122			3,830,451
Cost of shares reacquired		(28,089,715,189	)		(26,351,859,499	)
Change in net assets from fund share transactions		$971,005,261			$31,652,801
Total change in net assets		$971,005,261			$31,656,431
Net assets
At beginning of period		2,217,966,250			2,186,309,819
At end of period		$3,188,971,511			$2,217,966,250

See Notes to Financial Statements

11

Financial Statements

FINANCIAL HIGHLIGHTS

The financial highlights table is intended to help you understand the fund’s financial performance for the past 5 years. Certain information reflects financial results for a single fund share. The total returns in the table represent the rate by which an investor would have earned (or lost) on an investment in the fund share class (assuming reinvestment of all distributions) held for the entire period.

	Years ended 8/31
	2012			2011			2010			2009			2008
Net asset value, beginning of period		$1.00			$1.00			$1.00			$1.00			$1.00
Income (loss) from investment operations
Net investment income (d)		$0.00	(w)		$0.00	(w)		$0.00	(w)		$0.01			$0.04
Net realized and unrealized gain (loss) on investments		—			0.00	(w)		—			0.00	(w)		0.00	(w)
Total from investment operations		$0.00	(w)		$0.00	(w)		$0.00	(w)		$0.01			$0.04
Less distributions declared to shareholders
From net investment income		$(0.00	)(w)		$(0.00	)(w)		$(0.00	)(w)		$(0.01	)		$(0.04	)
Net asset value, end of period		$1.00			$1.00			$1.00			$1.00			$1.00
Total return (%) (r)		0.11			0.17			0.19			0.66			3.80
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		0.01			0.01			0.02			0.02			0.02
Expenses after expense reductions (f)		0.01			0.01			0.01			0.01			0.01
Net investment income		0.11			0.17			0.19			0.51			3.86
Net assets at end of period (000 omitted)		$3,188,972			$2,217,966			$2,186,310			$1,790,266			$701,840

(d) Per share data is based on average shares outstanding.

(f) Ratios do not reflect reductions from fees paid indirectly, if applicable.

(r) Certain expenses have been reduced without which performance would have been lower.

(w) Per share amount was less than $0.01.

See Notes to Financial Statements

12

NOTES TO FINANCIAL STATEMENTS

(1) Business and Organization

MFS Institutional Money Market Portfolio (the fund) is a series of MFS Series Trust XIV (the trust). The trust is organized as a Massachusetts business trust and is registered under the Investment Company Act of 1940, as amended, as an open-end management investment company. This fund is available only to investment companies managed by MFS.

(2) Significant Accounting Policies

General – The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. In the preparation of these financial statements, management has evaluated subsequent events occurring after the date of the fund’s Statement of Assets and Liabilities through the date that the financial statements were issued.

In this reporting period the fund adopted FASB Accounting Standards Update 2011-04, Fair Value Measurement (Topic 820) – Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRSs (“ASU 2011-04”). ASU 2011-04 seeks to improve the comparability of fair value measurements as presented and disclosed in financial statements prepared in accordance with U.S. GAAP and International Financial Reporting Standards (IFRS) by providing common requirements for fair value measurement and disclosure.

In December 2011, the Financial Accounting Standards Board issued Accounting Standards Update 2011-11, Balance Sheet (Topic 210) – Disclosures about Offsetting Assets and Liabilities (“ASU 2011-11”). Effective for annual reporting periods beginning on or after January 1, 2013 and interim periods within those annual periods, ASU 2011-11 is intended to enhance disclosure requirements on the offsetting of financial assets and liabilities. Although still evaluating the potential impacts of ASU 2011-11 to the fund, management expects that the impact of the fund’s adoption will be limited to additional financial statement disclosures.

Investment Valuations – Pursuant to procedures approved by the Board of Trustees, investments held by the fund are generally valued at amortized cost, which approximates market value. Amortized cost involves valuing an instrument at its cost as adjusted for amortization of premium or accretion of discount rather than its current market value. The amortized cost value of an instrument can be different from the market value of an instrument.

Various inputs are used in determining the value of the fund’s assets or liabilities. These inputs are categorized into three broad levels. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, an investment’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. The fund’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the investment. Level 1 includes unadjusted

13

Notes to Financial Statements – continued

quoted prices in active markets for identical assets or liabilities. Level 2 includes other significant observable market-based inputs (including quoted prices for similar securities, interest rates, prepayment speed, and credit risk). Level 3 includes unobservable inputs, which may include the adviser’s own assumptions in determining the fair value of investments. The following is a summary of the levels used as of August 31, 2012 in valuing the fund’s assets or liabilities:

Investments at Value	Level 1		Level 2		Level 3		Total
Short Term Securities		$—		$3,185,868,433		$—		$3,185,868,433

For further information regarding security characteristics, see the Portfolio of Investments.

Repurchase Agreements – The fund entered into repurchase agreements with approved counterparties. Each repurchase agreement is recorded at cost. The fund requires that the securities collateral in a repurchase transaction be transferred to a custodian. The fund monitors, on a daily basis, the value of the collateral to ensure that its value, including accrued interest, is greater than amounts owed to the fund under each such repurchase agreement.

Indemnifications – Under the fund’s organizational documents, its officers and Trustees may be indemnified against certain liabilities and expenses arising out of the performance of their duties to the fund. Additionally, in the normal course of business, the fund enters into agreements with service providers that may contain indemnification clauses. The fund’s maximum exposure under these agreements is unknown as this would involve future claims that may be made against the fund that have not yet occurred.

Investment Transactions and Income – Investment transactions are recorded on the trade date. Interest income is recorded on the accrual basis. All premium and discount is amortized or accreted for financial statement purposes in accordance with U.S. generally accepted accounting principles.

Fees Paid Indirectly – The fund’s custody fee may be reduced according to an arrangement that measures the value of cash deposited with the custodian by the fund. This amount, for the year ended August 31, 2012, is shown as a reduction of total expenses on the Statement of Operations.

Tax Matters and Distributions – The fund intends to qualify as a regulated investment company, as defined under Subchapter M of the Internal Revenue Code, and to distribute all of its taxable income, including realized capital gains. As a result, no provision for federal income tax is required. The fund’s federal tax returns, when filed, will remain subject to examination by the Internal Revenue Service for a three year period.

Distributions to shareholders are recorded on the ex-dividend date. Income and capital gain distributions are determined in accordance with income tax regulations, which may differ from U.S. generally accepted accounting principles. Certain capital accounts in the financial statements are periodically adjusted for permanent differences in order to reflect their tax character. These adjustments have no impact on net assets or net asset value per share. Temporary differences which arise from recognizing certain items of income, expense, gain or loss in different periods for financial statement and tax purposes will reverse at some time in the future. Distributions in excess of net

14

Notes to Financial Statements – continued

investment income or net realized gains are temporary overdistributions for financial statement purposes resulting from differences in the recognition or classification of income, expenses, or distributions for financial statement and tax purposes.

During the year ended August 31, 2012, there were no significant adjustments due to differences between book and tax accounting.

The tax character of distributions declared to shareholders for the last two fiscal years is as follows:

	8/31/12		8/31/11
Ordinary income (including any short-term capital gains)		$3,122,122		$3,830,451

The federal tax cost and the tax basis components of distributable earnings were as follows:

As of 8/31/12
Cost of investments	$3,185,868,433
Undistributed ordinary income	4,131
Capital loss carryforwards	(181,218	)
Other temporary differences	(4,131	)

Under the Regulated Investment Company Modernization Act of 2010 (the “Act”), net capital losses recognized after August 31, 2011 may be carried forward indefinitely, and their character is retained as short-term and/or long-term losses. Previously, net capital losses were carried forward for eight years and treated as short-term losses. As a transition rule, the Act requires that post-enactment net capital losses be used before pre-enactment net capital losses.

As of August 31, 2012, the fund had capital loss carryforwards available to offset future realized gains. Such losses expire as follows:

Pre-enactment losses:
8/31/17	$(181,218	)

(3) Transactions with Affiliates

Investment Adviser – The fund has an investment advisory agreement with MFS to provide overall investment management and related administrative services and facilities to the fund. MFS receives no compensation under this agreement.

Shareholder Servicing Agent – MFS Service Center, Inc. (MFSC), a wholly-owned subsidiary of MFS, provides transfer agent and recordkeeping functions in connection with the issuance, transfer, and redemption of shares of the fund under a Shareholder Servicing Agent Agreement. MFSC is not paid a fee for providing these services. MFSC receives payment from the fund for out-of-pocket expenses paid by MFSC on behalf of the fund. For the year ended August 31, 2012, these costs amounted to $910.

Administrator – MFS provides the fund with certain financial, legal, shareholder, and other administrative services under a Master Administrative Services Agreement between the fund and MFS. MFS is not paid a fee for providing these services.

Trustees’ and Officers’ Compensation – The fund may pay compensation to independent Trustees in the form of a retainer, attendance fees, and additional compensation to Board and Committee chairpersons. The fund does not pay

15

Notes to Financial Statements – continued

compensation directly to Trustees or officers of the fund who are also officers of the investment adviser, all of whom receive remuneration for their services to the fund from MFS. Certain officers and Trustees of the fund are officers or directors of MFS, MFD, and MFSC. The independent Trustees do not currently receive compensation from the fund.

Other – This fund and certain other funds managed by MFS (the funds) have entered into services agreements (the Agreements) which provide for payment of fees by the funds to Tarantino LLC and Griffin Compliance LLC in return for the provision of services of an Independent Chief Compliance Officer (ICCO) and Assistant ICCO, respectively, for the funds. The ICCO and Assistant ICCO are officers of the funds and the sole members of Tarantino LLC and Griffin Compliance LLC, respectively. The funds can terminate the Agreements with Tarantino LLC and Griffin Compliance LLC at any time under the terms of the Agreements. For the year ended August 31, 2012, the aggregate fees paid by the fund to Tarantino LLC and Griffin Compliance LLC were $23,663. MFS has agreed to reimburse the fund for a portion of the payments made by the fund in the amount of $10,698, which is shown as a reduction of total expenses in the Statement of Operations. Additionally, MFS has agreed to bear all expenses associated with office space, other administrative support, and supplies provided to the ICCO and Assistant ICCO.

(4) Shares of Beneficial Interest

The fund’s Declaration of Trust permits the Trustees to issue an unlimited number of full and fractional shares of beneficial interest.

The fund is solely invested in by other MFS funds for the purpose of investing excess cash balances on a short-term basis. The MFS funds do not invest in this fund for the purpose of exercising management or control. At the end of the period, the MFS International Value Fund, MFS Emerging Markets Debt Fund, MFS Government Securities Fund, MFS Research Bond Fund, MFS Utilities Fund, and MFS Bond Fund were the owners of record of approximately 10%, 8%, 7%, 6%, 6%, and 5%, respectively, of the value of outstanding voting shares of the fund. No other MFS fund owned more than 5% of the value of outstanding voting shares of the fund.

(5) Line of Credit

The fund and certain other funds managed by MFS participate in a $1.1 billion unsecured committed line of credit, subject to a $1 billion sublimit, provided by a syndication of banks under a credit agreement. Borrowings may be made for temporary financing needs. Interest is charged to each fund, based on its borrowings, generally at a rate equal to the higher of the Federal Reserve funds rate or one month LIBOR plus an agreed upon spread. A commitment fee, based on the average daily, unused portion of the committed line of credit, is allocated among the participating funds at the end of each calendar quarter. In addition, the fund and other funds managed by MFS have established unsecured uncommitted borrowing arrangements with certain banks for temporary financing needs. Interest is charged to each fund, based on its borrowings, at a rate equal to the Federal Reserve funds rate plus an agreed upon spread. For the year ended August 31, 2012, the fund’s commitment fee and interest expense were $18,886 and $0, respectively, and are separately reported on the Statement of Operations.

16

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Board of Trustees of MFS Series Trust XIV and the Shareholders of MFS Institutional Money Market Portfolio:

We have audited the accompanying statement of assets and liabilities, including the portfolio of investments, of MFS Institutional Money Market Portfolio (one of the portfolios comprising MFS Series Trust XIV) (the “Fund”) as of August 31, 2012, and the related statement of operations for the year then ended, the statements of changes in net assets for each of the two years in the period then ended, and the financial highlights for each of the five years in the period then ended. These financial statements and financial highlights are the responsibility of the Fund’s management. Our responsibility is to express an opinion on these financial statements and financial highlights based on our audits.

We conducted our audits in accordance with the standards of the Public Company Accounting Oversight Board (United States). 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. The Fund is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. Our audits included consideration of internal control over financial reporting as a basis for designing audit procedures that are appropriate in the circumstances, 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. An audit also includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. Our procedures included confirmation of securities owned as of August 31, 2012, by correspondence with the custodian and brokers; where replies were not received from brokers, we performed other auditing procedures. We believe that our audits provide a reasonable basis for our opinion.

In our opinion, the financial statements and financial highlights referred to above present fairly, in all material respects, the financial position of MFS Institutional Money Market Portfolio as of August 31, 2012, 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 five years in the period then ended, in conformity with accounting principles generally accepted in the United States of America.

DELOITTE & TOUCHE LLP

Boston, Massachusetts

October 17, 2012

17

TRUSTEES AND OFFICERS — IDENTIFICATION AND BACKGROUND

The Trustees and officers of the Trust, as of October 1, 2012, are listed below, together with their principal occupations during the past five years. (Their titles may have varied during that period.) The address of each Trustee and officer is 500 Boylston Street, Boston, Massachusetts 02116.

Name, Age	Position(s) Held with Fund	Trustee/Officer Since (h)	Principal Occupations During the Past Five Years	Other Directorships (j)
INTERESTED TRUSTEES
Robert J. Manning (k) (age 48)	Trustee	February 2004	Massachusetts Financial Services Company, Chairman, Chief Executive Officer and Director; President (until December 2009); Chief Investment Officer (until July 2010)	N/A
INDEPENDENT TRUSTEES
David H. Gunning (age 70)	Trustee and Chair of Trustees	January 2004	Retired; Cleveland-Cliffs Inc. (mining products and service provider), Vice Chairman/Director (until 2007)	Lincoln Electric Holdings, Inc. (welding equipment manufacturer), Director; Development Alternatives, Inc. (consulting), Director/Non-Executive Chairman; Portman Limited (mining), Director (until 2008)
Robert E. Butler (age 70)	Trustee	January 2006	Consultant – investment company industry regulatory and compliance matters	N/A
Maureen R. Goldfarb (age 57)	Trustee	January 2009	Private investor	N/A
William R. Gutow (age 71)	Trustee	December 1993	Private investor and real estate consultant; Capitol Entertainment Management Company (video franchise), Vice Chairman	Atlantic Coast Tan (tanning salons), Vice Chairman (until 2007); Texas Donuts (donut franchise), Vice Chairman (until 2010)
Michael Hegarty (age 67)	Trustee	December 2004	Private investor	N/A
John P. Kavanaugh (age 57)	Trustee	January 2009	Private investor	N/A

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Trustees and Officers – continued

Name, Age	Position(s) Held with Fund	Trustee/Officer Since (h)	Principal Occupations During the Past Five Years	Other Directorships (j)
J. Dale Sherratt (age 74)	Trustee	June 1989	Insight Resources, Inc. (acquisition planning specialists), President; Wellfleet Investments (investor in health care companies), Managing General Partner	N/A
Laurie J. Thomsen (age 55)	Trustee	March 2005	Private investor; New Profit, Inc. (venture philanthropy), Executive Partner (until 2010)	The Travelers Companies (insurance), Director
Robert W. Uek (age 71)	Trustee	January 2006	Consultant to investment company industry	N/A
OFFICERS
John M. Corcoran (k) (age 47)	President	October 2008	Massachusetts Financial Services Company, Senior Vice President (since October 2008); State Street Bank and Trust (financial services provider), Senior Vice President, (until September 2008)	N/A
Christopher R. Bohane (k) (age 38)	Assistant Secretary and Assistant Clerk	July 2005	Massachusetts Financial Services Company, Vice President and Senior Counsel	N/A
Kino Clark (k) (age 44)	Assistant Treasurer	January 2012	Massachusetts Financial Services Company, Vice President	N/A
Thomas H. Connors (k) (age 53)	Assistant Secretary and Assistant Clerk	September 2012	Massachusetts Financial Services Company, Vice President and Senior Counsel; Deutsche Asset Management, Director and Senior Counsel (until 2012)	N/A

19

Trustees and Officers – continued

Name, Age	Position(s) Held with Fund	Trustee/Officer Since (h)	Principal Occupations During the Past Five Years	Other Directorships (j)
Ethan D. Corey (k) (age 48)	Assistant Secretary and Assistant Clerk	July 2005	Massachusetts Financial Services Company, Senior Vice President and Associate General Counsel	N/A
David L. DiLorenzo (k) (age 44)	Treasurer	July 2005	Massachusetts Financial Services Company, Senior Vice President	N/A
Robyn L. Griffin (age 37)	Assistant Independent Chief Compliance Officer	August 2008	Griffin Compliance LLC (provider of compliance services), Principal (since August 2008); State Street Corporation (financial services provider), Mutual Fund Administration Assistant Vice President (October 2006 – July 2008);	N/A
Brian E. Langenfeld (k) (age 39)	Assistant Secretary and Assistant Clerk	June 2006	Massachusetts Financial Services Company, Vice President and Senior Counsel	N/A
Susan S. Newton (k) (age 62)	Assistant Secretary and Assistant Clerk	May 2005	Massachusetts Financial Services Company, Senior Vice President and Associate General Counsel	N/A
Susan A. Pereira (k) (age 41)	Assistant Secretary and Assistant Clerk	July 2005	Massachusetts Financial Services Company, Vice President and Senior Counsel	N/A
Kasey L. Phillips (k) (age 41)	Assistant Treasurer	September 2012	Massachusetts Financial Services Company; Wells Fargo Funds Management, LLC, Senior Vice President, Fund Treasurer (until 2012)	N/A

20

Trustees and Officers – continued

Name, Age	Position(s) Held with Fund	Trustee/Officer Since (h)	Principal Occupations During the Past Five Years	Other Directorships (j)
Mark N. Polebaum (k) (age 60)	Secretary and Clerk	January 2006	Massachusetts Financial Services Company, Executive Vice President, General Counsel and Secretary	N/A
Frank L. Tarantino (age 68)	Independent Chief Compliance Officer	June 2004	Tarantino LLC (provider of compliance services), Principal	N/A
Richard S. Weitzel (k) (age 42)	Assistant Secretary and Assistant Clerk	October 2007	Massachusetts Financial Services Company, Senior Vice President and Associate General Counsel	N/A
James O. Yost (k) (age 52)	Deputy Treasurer	September 1990	Massachusetts Financial Services Company, Senior Vice President	N/A

(h) Date first appointed to serve as Trustee/officer of an MFS fund. Each Trustee has served continuously since appointment unless indicated otherwise. For the period from December 15, 2004 until February 22, 2005, Mr. Manning served as Advisory Trustee. For the period October 2008, until January 2012, Mr. Corcoran served as Treasurer of the Funds. Prior to January 2012, Messrs. DiLorenzo and Yost served as Assistant Treasurers of the Funds.

(j) Directorships or trusteeships of companies required to report to the Securities and Exchange Commission (i.e., “public companies”).

(k) “Interested person” of the Trust within the meaning of the Investment Company Act of 1940 (referred to as the 1940 Act), which is the principal federal law governing investment companies like the fund, as a result of position with MFS. The address of MFS is 500 Boylston Street, Boston, Massachusetts 02116.

Each Trustee has been elected by shareholders and each Trustee and officer holds office until his or her successor is chosen and qualified or until his or her earlier death, resignation, retirement or removal. The Trust does not hold annual meetings for the purpose of electing Trustees, and Trustees are not elected for fixed terms. Messrs. Butler, Kavanaugh, Uek and Ms. Thomsen are members of the Trust’s Audit Committee.

Each of the Fund’s Trustees and officers holds comparable positions with certain other funds of which MFS or a subsidiary is the investment adviser or distributor, and, in the case of the officers, with certain affiliates of MFS. As of January 1, 2012, the Trustees served as board members of 131 funds within the MFS Family of Funds.

21

Trustees and Officers – continued

The Statement of Additional Information for the Fund includes further information about the Trustees and is available without charge upon request by calling 1-800-225-2606.

Investment Adviser	Custodian
Massachusetts Financial Services Company 500 Boylston Street Boston, MA 02116-3741	JPMorgan Chase Bank One Chase Manhattan Plaza New York, NY 10081
Portfolio Manager	Independent Registered Public Accounting Firm
Edward O’Dette	Deloitte & Touche LLP 200 Berkeley Street Boston, MA 02116

22

BOARD REVIEW OF INVESTMENT ADVISORY AGREEMENT

The Investment Company Act of 1940 requires that both the full Board of Trustees and a majority of the non-interested (“independent”) Trustees, voting separately, annually approve the continuation of the Fund’s investment advisory agreement with MFS. The Trustees consider matters bearing on the Fund and its advisory arrangements at their meetings throughout the year, including a review of performance data at each regular meeting. In addition, the independent Trustees met several times over the course of three months beginning in May and ending in July, 2012 (“contract review meetings”) for the specific purpose of considering whether to approve the continuation of the investment advisory agreement for the Fund and the other investment companies that the Board oversees (the “MFS Funds”). The independent Trustees were assisted in their evaluation of the Fund’s investment advisory agreement by independent legal counsel, from whom they received separate legal advice and with whom they met separately from MFS during various contract review meetings. The independent Trustees were also assisted in this process by the MFS Funds’ Independent Chief Compliance Officer, a full-time senior officer appointed by and reporting to the independent Trustees.

In connection with their deliberations regarding the continuation of the investment advisory agreement, the Trustees, including the independent Trustees, considered such information and factors as they believed, in light of the legal advice furnished to them and their own business judgment, to be relevant. The investment advisory agreement for the Fund was considered separately, although the Trustees also took into account the common interests of all MFS Funds in their review. As described below, the Trustees considered the nature, quality, and extent of the various investment advisory, administrative, and shareholder services performed by MFS under the existing investment advisory agreement and other arrangements with the Fund.

As part of their deliberations, the Trustees took into account that the Fund was formed solely to act as a cash sweep vehicle for other MFS funds, and that shares of the Fund are not distributed or sold to the public. The Trustees gave substantial consideration to the fact that MFS does not charge a separate advisory fee to the Fund under the investment advisory agreement or charge transfer agency fees, administrative services fees, sales loads or distribution and service fees to the Fund, but that MFS receives advisory and other fees from the MFS funds that invest their cash balances in the Fund.

In connection with their contract review meetings, the Trustees received and relied upon materials that included, among other items: (i) information provided by Lipper Inc., an independent third party, on the investment performance of the Fund for various time periods ended December 31, 2011 and the investment performance of a group of funds with substantially similar investment classifications/objectives (the “Lipper performance universe”), (ii) information provided by Lipper Inc. on the Fund’s expenses and the fees and expenses of comparable funds identified by Lipper Inc. (the “Lipper expense group”), (iii) information provided by MFS on the advisory fees of comparable portfolios of other clients of MFS, including institutional separate accounts and other clients, (iv) information as to whether and to what extent applicable expense waivers or reimbursements are observed for the Fund, (v) information regarding MFS’ financial results and financial condition, including MFS’ and certain of its affiliates’ estimated profitability from services performed for the Fund and the MFS Funds as a

23

Board Review of Investment Advisory Agreement – continued

whole, and compared to MFS’ institutional business, (vi) MFS’ views regarding the outlook for the mutual fund industry and the strategic business plans of MFS, (vii) descriptions of various functions performed by MFS for the Funds, such as compliance monitoring and portfolio trading practices, and (viii) information regarding the overall organization of MFS, including information about MFS’ senior management and other personnel providing investment advisory, administrative and other services to the Fund and the other MFS Funds. The comparative performance, fee and expense information prepared and provided by Lipper Inc. was not independently verified and the independent Trustees did not independently verify any information provided to them by MFS.

The Trustees’ conclusion as to the continuation of the investment advisory agreement was based on a comprehensive consideration of all information provided to the Trustees and not the result of any single factor. Some of the factors that figured particularly in the Trustees’ deliberations are described below, although individual Trustees may have evaluated the information presented differently from one another, giving different weights to various factors. It is also important to recognize that the fee arrangements for the Fund and other MFS Funds are the result of years of review and discussion between the independent Trustees and MFS, that certain aspects of such arrangements may receive greater scrutiny in some years than in others, and that the Trustees’ conclusions may be based, in part, on their consideration of these same arrangements during the course of the year and in prior years.

Based on information provided by Lipper Inc. and MFS, the Trustees reviewed the Fund’s total return investment performance as well as the performance of peer groups of funds over various time periods. The Trustees placed particular emphasis on the total return performance of the Fund’s shares in comparison to the performance of funds in its Lipper performance universe over the three-year period ended December 31, 2011, which the Trustees believed was a long enough period to reflect differing market conditions. The total return performance of the Fund’s shares was in the 2nd quintile relative to the other funds in the universe for this three-year period (the 1st quintile being the best performers and the 5th quintile being the worst performers). The total return performance of the Fund’s shares was in the 1st quintile for the one-year period ended December 31, 2011 relative to the Lipper performance universe. The Fund commenced operations in 2007; therefore, no performance data for the five-year period was available for the Fund. Because of the passage of time, these performance results may differ from the performance results for more recent periods, including those shown elsewhere in this report.

In the course of their deliberations, the Trustees took into account information provided by MFS in connection with the contract review meetings, as well as during investment review meetings conducted with portfolio management personnel during the course of the year regarding the Fund’s performance. After reviewing these and related factors, the Trustees concluded, within the context of their overall conclusions regarding the investment advisory agreement, that they were satisfied with MFS’ responses and efforts relating to investment performance.

Because the Fund does not pay an advisory fee, the Trustees did not consider the extent to which economies of scale would be realized due to the Fund’s growth of

24

Board Review of Investment Advisory Agreement – continued

assets, whether fee levels reflect economies of scale for the Fund’s shareholders, or the fees paid by similar funds to other investment advisers or by similar clients of MFS. In assessing the reasonableness of the Fund’s expenses, the Trustees considered, among other information, the total expense ratio of the Fund’s shares as a percentage of average daily net assets, noting that the Fund’s total expense ratio was lower than the Lipper expense group median.

The Trustees also considered information prepared by MFS relating to MFS’ costs and profits with respect to the Fund, the MFS Funds considered as a group, and other investment companies and accounts advised by MFS, as well as MFS’ methodologies used to determine and allocate its costs to the MFS Funds, the Fund and other accounts and products for purposes of estimating profitability.

In addition, the Trustees considered MFS’ resources and related efforts to continue to retain, attract and motivate capable personnel to serve the Fund. The Trustees also considered current and developing conditions in the financial services industry, including the presence of large and well-capitalized companies which are spending, and appear to be prepared to continue to spend, substantial sums to engage personnel and to provide services to competing investment companies. In this regard, the Trustees also considered the financial resources of MFS and its ultimate parent, Sun Life Financial Inc. The Trustees also considered the advantages and possible disadvantages to the Fund of having an adviser that also serves other investment companies as well as other accounts.

The Trustees also considered the nature, quality, cost, and extent of administrative, transfer agency, and distribution services provided to the Fund by MFS and its affiliates under agreements and plans other than the investment advisory agreement. The Trustees also considered the nature, extent and quality of certain other services MFS performs or arranges for on the Fund’s behalf, which may include securities lending programs, directed expense payment programs, class action recovery programs, and MFS’ interaction with third-party service providers, principally custodians and sub-custodians. The Trustees concluded that the various non-advisory services provided by MFS and its affiliates on behalf of the Fund were satisfactory.

The Trustees also considered benefits to MFS from the use of the Fund’s portfolio brokerage commissions, if applicable, to pay for investment research, and various other factors. Additionally, the Trustees considered so-called “fall-out benefits” to MFS such as reputational value derived from serving as investment manager to the Fund.

Based on their evaluation of factors that they deemed to be material, including those factors described above, the Board of Trustees, including the independent Trustees, concluded that the Fund’s investment advisory agreement with MFS should be continued for an additional one-year period, commencing August 1, 2012.

A discussion regarding the Board’s most recent review and renewal of the fund’s Investment Advisory Agreement with MFS is available by clicking on the fund’s name under “Mutual Funds” in the “Products and Performance” section of the MFS Web site (mfs.com).

25

PROXY VOTING POLICIES AND INFORMATION

A general description of the MFS funds’ proxy voting policies and procedures is available without charge, upon request, by calling 1-800-225-2606, by visiting the Proxy Voting section of mfs.com or by visiting the SEC’s Web site at http://www.sec.gov.

Information regarding how the fund voted proxies relating to portfolio securities during the most recent twelve-month period ended June 30 is available without charge by visiting the Proxy Voting section of mfs.com or by visiting the SEC’s Web site at http://www.sec.gov.

QUARTERLY PORTFOLIO DISCLOSURE

The fund will file a complete schedule of portfolio holdings with the Securities and Exchange Commission (the Commission) for the first and third quarters of each fiscal year on Form N-Q. A shareholder can obtain the quarterly portfolio holdings report at mfs.com. The fund’s Form N-Q is also available on the EDGAR database on the Commission’s Internet Web site at http://www.sec.gov, and may be reviewed and copied at the:

Public Reference Room

Securities and Exchange Commission

100 F Street, NE, Room 1580

Washington, D.C. 20549

Information on the operation of the Public Reference Room may be obtained by calling the Commission at 1-800-SEC-0330. Copies of the fund’s Form N-Q also may be obtained, upon payment of a duplicating fee, by electronic request at the following e-mail address: publicinfo@sec.gov or by writing the Public Reference Section at the above address.

FURTHER INFORMATION

From time to time, MFS may post important information about the fund or the MFS funds on the MFS web site (mfs.com). This information is available by visiting the “News & Commentary” section of mfs.com.

FEDERAL TAX INFORMATION (unaudited)

The fund will notify shareholders of amounts for use in preparing 2012 income tax forms in January 2013.

26

rev. 3/11

FACTS WHAT DOES MFS DO WITH YOUR PERSONAL INFORMATION?

Why? Financial companies choose how they share your personal information. Federal law gives consumers the right to limit some but not all sharing. Federal law also requires us to tell you how we collect, share, and protect your personal information. Please read this notice carefully to understand what we do.

What? The types of personal information we collect and share depend on the product or service you have with us. This information can include:   •Social Security number and account balances •Account transactions and transaction history •Checking account information and wire transfer instructions   When you are no longer our customer, we continue to share your information as described in this notice.

How? All financial companies need to share customers’ personal information to run their everyday business. In the section below, we list the reasons financial companies can share their customers’ personal information; the reasons MFS chooses to share; and whether you can limit this sharing.

Reasons we can share your personal information	Does MFS share?	Can you limit this sharing?
For our everyday business purposes – such as to process your transactions, maintain your account(s), respond to court orders and legal investigations, or report to credit bureaus	Yes	No
For our marketing purposes – to offer our products and services to you	No	We don’t share
For joint marketing with other financial companies	No	We don’t share
For our affiliates’ everyday business purposes – information about your transactions and experiences	No	We don’t share
For our affiliates’ everyday business purposes – information about your creditworthiness	No	We don’t share
For nonaffiliates to market to you	No	We don’t share

Questions? Call 800-225-2606 or go to mfs.com.

27

Page 2

Who we are
Who is providing this notice?	MFS Funds, MFS Investment Management, MFS Institutional Advisors, Inc., MFS Fund Distributors, Inc., MFS Heritage Trust Company, and MFS Service Center, Inc.

What we do
How does MFS protect my personal information?	To protect your personal information from unauthorized access and use, we use security measures that comply with federal law. These measures include procedural, electronic, and physical safeguards for the protection of the personal information we collect about you.
How does MFS collect my personal information?	We collect your personal information, for example, when you •open an account or provide account information •direct us to buy securities or direct us to sell your securities •make a wire transfer We also collect your personal information from others, such as credit bureaus, affiliates and other companies.
Why can’t I limit all sharing?	Federal law gives you the right to limit only •sharing for affiliates’ everyday business purposes – information about your creditworthiness •affiliates from using your information to market to you •sharing for nonaffiliates to market to you State laws and individual companies may give you additional rights to limit sharing.

Definitions
Affiliates	Companies related by common ownership or control. They can be financial and nonfinancial companies. •MFS does not share personal information with affiliates, except for everyday business purposes as described on page one of this notice.
Nonaffiliates	Companies not related by common ownership or control. They can be financial and nonfinancial companies. •MFS does not share with nonaffiliates so they can market to you.
Joint Marketing	A formal agreement between nonaffiliated financial companies that together market financial products or services to you. •MFS doesn’t jointly market.

Other important information

If you own an MFS product or receive an MFS service in the name of a third party such as a bank or broker-dealer, their privacy policy may apply to you instead of ours.

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CONTACT

WEB SITE

mfs.com

MFS TALK

1-800-637-8255

24 hours a day

ACCOUNT SERVICE AND LITERATURE

Shareholders

1-800-225-2606

Financial advisors

1-800-343-2829

Retirement plan services

1-800-637-1255

MAILING ADDRESS

MFS Service Center, Inc.

P.O. Box 55824

Boston, MA 02205-5824

OVERNIGHT MAIL

MFS Service Center, Inc.

c/o Boston Financial Data Services

30 Dan Road

Canton, MA 02021-2809

ITEM 2. CODE OF ETHICS.

The Registrant has adopted a Code of Ethics pursuant to Section 406 of the Sarbanes-Oxley Act and as defined in Form N-CSR that applies to the Registrant’s principal executive officer and principal financial and accounting officer. During the period covered by this report, the Registrant has not amended any provision in its Code of Ethics (the “Code”) that relates to an element of the Code’s definitions enumerated in paragraph (b) of Item 2 of this Form N-CSR. During the period covered by this report, the Registrant did not grant a waiver, including an implicit waiver, from any provision of the Code.

A copy of the Code of Ethics is filed as an exhibit to this Form N-CSR.

ITEM 3. AUDIT COMMITTEE FINANCIAL EXPERT.

Messrs. Robert E. Butler, John P. Kavanaugh and Robert W. Uek and Ms. Laurie J. Thomsen, members of the Audit Committee, have been determined by the Board of Trustees in their reasonable business judgment to meet the definition of “audit committee financial expert” as such term is defined in Form N-CSR. In addition, Messrs. Butler, Kavanaugh and Uek and Ms. Thomsen are “independent” members of the Audit Committee (as such term has been defined by the Securities and Exchange Commission in regulations implementing Section 407 of the Sarbanes-Oxley Act of 2002). The Securities and Exchange Commission has stated that the designation of a person as an audit committee financial expert pursuant to this Item 3 on the Form N-CSR does not impose on such a person any duties, obligations or liability that are greater than the duties, obligations or liability imposed on such person as a member of the Audit Committee and the Board of Trustees in the absence of such designation or identification.

ITEM 4. PRINCIPAL ACCOUNTANT FEES AND SERVICES.

Items 4(a) through 4(d) and 4(g):

The Board of Trustees has appointed Deloitte & Touche LLP (“Deloitte”) to serve as independent accountants to the series of the Registrant (the series referred to as the “Fund”). The tables below set forth the audit fees billed to the Fund as well as fees for non-audit services provided to the Fund and/or to the Fund’s investment adviser, Massachusetts Financial Services Company (“MFS”), and to various entities either controlling, controlled by, or under common control with MFS that provide ongoing services to the Fund (“MFS Related Entities”).

For the fiscal years ended August 31, 2012 and 2011, audit fees billed to the Fund by Deloitte were as follows:

	Audit Fees
Fees billed by Deloitte:	2012		2011
MFS Institutional Money Market Portfolio		24,088		23,214

For the fiscal years ended August 31, 2012 and 2011, fees billed by Deloitte for audit-related, tax and other services provided to the Fund and for audit-related, tax and other services provided to MFS and MFS Related Entities were as follows:

	Audit-Related Fees1				Tax Fees2				All Other Fees3
Fees billed by Deloitte:	2012		2011		2012		2011		2012		20114
To MFS Institutional Money Market Portfolio		0		0		4,284		4,123		1,448		1,248
	Audit-Related Fees				Tax Fees				All Other Fees
Fees billed by Deloitte:	2012		20114		2012		2011		2012		20114
To MFS and MFS Related Entities of MFS Institutional Money Market Portfolio*		1,249,664		810,204		0		0		0		113,100

Aggregate fees for non-audit services:	2012		20114
To MFS Institutional Money Market Portfolio, MFS and MFS Related Entities#		1,542,916		1,352,891

^*  This amount reflects the fees billed to MFS and MFS Related Entities for non-audit services relating directly to the operations and financial reporting of the Fund (portions of which services also related to the operations and financial reporting of other funds within the MFS Funds complex).

# This amount reflects the aggregate fees billed by Deloitte for non-audit services rendered to the Fund and for non-audit services rendered to MFS and the MFS Related Entities.

¹  The fees included under “Audit-Related Fees” are fees related to assurance and related services that are reasonably related to the performance of the audit or review of financial statements, but not reported under “Audit Fees,” including accounting consultations, agreed-upon procedure reports, attestation reports, comfort letters and internal control reviews.

²  The fees included under “Tax Fees” are fees associated with tax compliance, tax advice and tax planning, including services relating to the filing or amendment of federal, state or local income tax returns, regulated investment company qualification reviews and tax distribution and analysis.

³  The fees included under “All Other Fees” are fees for products and services provided by Deloitte other than those reported under “Audit Fees,” “Audit-Related Fees” and “Tax Fees,” including fees for services related to review of internal controls and Rule 38a-1 compliance program.

⁴  Certain fees reported in 2011 have been restated in this filing from those reported in the Registrant’s filing for the reporting period ended August 31, 2011.

Item 4(e)(1):

Set forth below are the policies and procedures established by the Audit Committee of the Board of Trustees relating to the pre-approval of audit and non-audit related services:

To the extent required by applicable law, pre-approval by the Audit Committee of the Board is needed for all audit and permissible non-audit services rendered to the Funds and all permissible non-audit services rendered to MFS or MFS Related Entities if the services relate directly to the operations and financial reporting of the Registrant. Pre-approval is currently on an engagement-by-engagement basis. In the event pre-approval of such services is necessary between regular meetings of the Audit Committee and it is not practical to wait to seek pre-approval at the next regular meeting of the Audit Committee, pre-approval of such services may be referred to the Chair of the Audit Committee for approval; provided that the Chair may not pre-approve any individual engagement for such services exceeding $50,000 or multiple engagements for such services in the aggregate exceeding $100,000 in each period between regular meetings of the Audit Committee. Any engagement pre-approved by the Chair between regular meetings of the Audit Committee shall be presented for ratification by the entire Audit Committee at its next regularly scheduled meeting.

Item 4(e)(2):

None, or 0%, of the services relating to the Audit-Related Fees, Tax Fees and All Other Fees paid by the Fund and MFS and MFS Related Entities relating directly to the operations and financial reporting of the Registrant disclosed above were approved by the audit committee pursuant to paragraphs (c)(7)(i)(C) of Rule 2-01 of Regulation S-X (which permits audit committee approval after the start of the engagement with respect to services other than audit, review or attest services, if certain conditions are satisfied).

Item 4(f): Not applicable.

Item 4(h): The Registrant’s Audit Committee has considered whether the provision by a Registrant’s independent registered public accounting firm of non-audit services to MFS and MFS Related Entities that were not pre-approved by the Committee (because such services did not relate directly to the operations and financial reporting of the Registrant) was compatible with maintaining the independence of the independent registered public accounting firm as the Registrant’s principal auditors.

ITEM 5. AUDIT COMMITTEE OF LISTED REGISTRANTS.

Not applicable to the Registrant.

ITEM 6. INVESTMENTS

A schedule of investments of the Registrant is included as part of the report to shareholders of such series under Item 1 of this Form N-CSR.

ITEM 7. DISCLOSURE OF PROXY VOTING POLICIES AND PROCEDURES FOR CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable to the Registrant.

ITEM 8. PORTFOLIO MANAGERS OF CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable to the Registrant.

ITEM 9. PURCHASES OF EQUITY SECURITIES BY CLOSED-END MANAGEMENT INVESTMENT COMPANY AND AFFILIATED PURCHASERS.

Not applicable to the Registrant.

ITEM 10. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS.

There were no material changes to the procedures by which shareholders may send recommendations to the Board for nominees to the Registrant’s Board since the Registrant last provided disclosure as to such procedures in response to the requirements of Item 407 (c)(2)(iv) of Regulation S-K or this Item.

ITEM 11. CONTROLS AND PROCEDURES.

(a) Based upon their evaluation of the effectiveness of the registrant’s disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940 (the “Act”)) as conducted within 90 days of the filing date of this report on Form N-CSR, the registrant’s principal financial officer and principal executive officer have concluded that those disclosure controls and procedures provide reasonable assurance that the material information required to be disclosed by the registrant on this report is recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission’s rules and forms.

(b) There were no changes in the registrant’s internal controls over financial reporting (as defined in Rule 30a-3(d) under the Act) that occurred during the second fiscal quarter of the period covered by the report that have materially affected, or are reasonably likely to materially affect, the registrant’s internal control over financial reporting.

ITEM 12. EXHIBITS.

(a) File the exhibits listed below as part of this form. Letter or number the exhibits in the sequence indicated.

(1) Any code of ethics, or amendment thereto, that is the subject of the disclosure required by Item 2, to the extent that the registrant intends to satisfy the Item 2 requirements through filing of an exhibit: Code of Ethics attached hereto.

(2) A separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2 under the Act (17 CFR 270.30a-2): Attached hereto.

(b) If the report is filed under Section 13(a) or 15(d) of the Exchange Act, provide the certifications required by Rule 30a-2(b) under the Act (17 CFR 270.30a-2(b)), Rule 13a-14(b) or Rule 15d-14(b) under the Exchange Act (17 CFR 240.13a-14(b) or 240.15d-14(b)) and Section 1350 of Chapter 63 of Title 18 of the United States Code (18 U.S.C. 1350) as an exhibit. A certification furnished pursuant to this paragraph will not be deemed “filed” for the purposes of Section 18 of the Exchange Act (15 U.S.C. 78r), or otherwise subject to the liability of that section. Such certification will not be deemed to be incorporated by reference into any filing under the Securities Act of 1933 or the Exchange Act, except to the extent that the registrant specifically incorporates it by reference: Attached hereto.

Notice

A copy of the Amended and Restated Declaration of Trust, as amended, of the Registrant is on file with the Secretary of State of The Commonwealth of Massachusetts and notice is hereby given that this instrument is executed on behalf of the Registrant by an officer of the Registrant as an officer and not individually and the obligations of or arising out of this instrument are not binding upon any of the Trustees or shareholders individually, but are binding only upon the assets and property of the respective constituent series of the Registrant.

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.

(Registrant) MFS SERIES TRUST XIV

By (Signature and Title)*	JOHN M. CORCORAN
	John M. Corcoran, President

Date: October 17, 2012

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 (Signature and Title)*	JOHN M. CORCORAN
	John M. Corcoran, President (Principal Executive Officer)

Date: October 17, 2012

By (Signature and Title)*	DAVID L. DILORENZO
	David L. DiLorenzo, Treasurer (Principal Financial Officer and Accounting Officer)

Date: October 17, 2012

* Print name and title of each signing officer under his or her signature.