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 811-21460

                          Pioneer Series Trust II
               (Exact name of registrant as specified in charter)


                       60 State Street, Boston, MA 02109
              (Address of principal executive offices) (ZIP code)


            Terrence J. Cullen, Amundi Pioneer Asset Management, Inc.,
                       60 State Street, Boston, MA 02109
                    (Name and address of agent for service)


Registrant's telephone number, including area code:  (617) 742-7825


Date of fiscal year end:  December 31


Date of reporting period:  January 1, 2019 through June 30, 2019


Form N-CSR is to be used by management investment companies to file reports with
the Commission not later than 10 days after the transmission to stockholders of
any report that is required to be transmitted to stockholders under Rule 30e-1
under the Investment Company Act of 1940 (17 CFR 270.30e-1).  The Commission may
use the information provided on Form N-CSR in its regulatory, disclosure review,
inspection, and policymaking roles.

A registrant is required to disclose the information specified by Form N-CSR,
and the Commission will make this information public. A registrant is not
required to respond to the collection of information contained in Form N-CSR
unless the Form displays a currently valid Office of Management and Budget
("OMB") control number. Please direct comments concerning the accuracy of the
information collection burden estimate and any suggestions for reducing the
burden to Secretary, Securities and Exchange Commission, 450 Fifth Street, NW,
Washington, DC 20549-0609.  The OMB has reviewed this collection of information
under the clearance requirements of 44 U.S.C. ss. 3507.


ITEM 1. REPORTS TO STOCKHOLDERS.


                                Pioneer AMT-Free
                                Municipal Fund

--------------------------------------------------------------------------------
                                Semiannual Report | June 30, 2019
--------------------------------------------------------------------------------

                                Ticker Symbols:

                                Class A   PBMFX
                                Class C   MNBCX
                                Class Y   PBYMX

Beginning in February 2021, as permitted by regulations adopted by the
Securities and Exchange Commission, paper copies of the Fund's shareholder
reports like this one 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 broker-dealer, bank or insurance company. Instead, the
reports will be made available on the Fund's 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 electronically by
contacting your financial intermediary or, if you invest directly with the
Fund, by calling 1-800-225-6292.

You may elect to receive all future reports in paper free of charge. If you
invest directly with the Fund, you can inform the Fund that you wish to
continue receiving paper copies of your shareholder reports by calling
1-800-225-6292. If you invest through a financial intermediary, you can contact
your financial intermediary to request that you continue to receive paper
copies of your shareholder reports. Your election to receive reports in paper
will apply to all funds held in your account if you invest through your
financial intermediary or all funds held within the Pioneer Fund complex if you
invest directly.

                        [LOGO]   Amundi Pioneer
                                 ==============
                               ASSET MANAGEMENT



                       visit us: www.amundipioneer.com/us



Table of Contents



                                                                          
President's Letter                                                            2

Portfolio Management Discussion                                               4

Portfolio Summary                                                             9

Prices and Distributions                                                     11

Performance Update                                                           12

Comparing Ongoing Fund Expenses                                              15

Schedule of Investments                                                      17

Financial Statements                                                         33

Notes to Financial Statements                                                40

Trustees, Officers and Service Providers                                     49


                 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 1



President's Letter

Since 1928, active portfolio management based on in-depth, fundamental
research, has been the foundation of Amundi Pioneer's investment approach. We
believe an active management investment strategy is a prudent approach to
investing, especially during periods of market volatility, which can result
from any number of risk factors, including slow U.S. economic growth, rising
interest rates, and geopolitical factors. Of course, in today's global economy,
risk factors extend well beyond U.S. borders. In fact, it's not unusual for
political and economic issues on the international front to cause or contribute
to volatility in U.S. markets.

At Amundi Pioneer, each security under consideration is researched by our team
of experienced investment professionals, who communicate directly with the
management teams of those companies. At the end of this research process, if we
have conviction in a company's business model and management team, and regard
the security as a potentially solid investment opportunity, an Amundi Pioneer
portfolio manager makes an active decision to invest in that security. The
portfolio resulting from these decisions represents an expression of his or her
convictions, and strives to balance overall risk and return opportunity.

As an example, the Standard & Poor's 500 Index -- the predominant benchmark for
many U.S. Large-Cap Core Equity funds -- has 500 stocks. An Amundi Pioneer
portfolio manager chooses to invest in only those companies that he or she
believes can offer the most attractive opportunities to pursue the fund's
investment objective, thus potentially benefiting the fund's shareowners. This
process results in a portfolio that does not own all 500 stocks, but a much
narrower universe.

The same active decision to invest in a company is also applied when we decide
to sell a security, either due to changing fundamentals, valuation concerns, or
market risks. We apply this active decision-making across all of our equity,
fixed-income, and global portfolios.

Today, as investors, we have many options. It is our view that active
management can serve shareholders well not only when markets are thriving, but
also during periods of market volatility and uncertainty, thus making it a
compelling investment choice. As you consider the many choices today, we
encourage you to work with your financial advisor to develop an overall
investment plan that addresses both your short- and long-term goals, and to
implement such a plan in a disciplined manner.

2 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



We greatly appreciate the trust you have placed in us and look forward to
continuing to serve you in the future.

Sincerely,

/s/ Lisa M. Jones

Lisa M. Jones
Head of the Americas, President and CEO of U.S.
Amundi Pioneer Asset Management USA, Inc.
June 30, 2019

Any information in this shareowner report regarding market or economic trends
or the factors influencing the Fund's historical or future performance are
statements of opinion as of the date of this report. Past performance is no
guarantee of future results.

                 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 3



Portfolio Management Discussion | 6/30/19

In the following interview, Lead Portfolio Manager David Eurkus outlines the
investment environment for tax-free bonds during the six-month period ended
June 30, 2019, and the factors that affected the performance of Pioneer
AMT-Free Municipal Fund during the period. Mr. Eurkus, a Managing Director,
Director of Municipals, and a portfolio manager at Amundi Pioneer Asset
Management, Inc. (Amundi Pioneer), is responsible for the day-to-day management
of the Fund, along with Jonathan Chirunga, a Managing Director, Deputy Director
of Municipals, and a portfolio manager at Amundi Pioneer.

Q     How did the Fund perform during the six-month period ended June 30, 2019?

A     Pioneer AMT-Free Municipal Fund's Class A shares returned 5.90% at net
      asset value during the six-month period ended June 30, 2019, while the
      Fund's benchmark, the Bloomberg Barclays Municipal Bond Index (the
      Bloomberg Barclays Index), returned 5.09%. During the same six-month
      period, the average return of the 176 mutual funds in Morningstar's
      Municipal National Long Funds Category was 5.85%.

Q     How would you describe the investment environment for tax-exempt bonds
      during the six-month period ended June 30, 2019?

A     The investment environment for municipal bonds was extremely favorable
      over the past six months. Key factors driving the positive conditions in
      the municipal market over the period included sharp declines in U.S.
      Treasury medium- and longer-term rates, the U.S. Federal Reserve (the Fed)
      abruptly shifting from monetary tightening to a more accommodative policy
      stance, and strong demand for tax-free bonds combined with limited supply.
      In addition, the municipal bond market continued to benefit from the
      longer-term effects of the U.S. tax reform legislation passed in late
      2017, which went into effect in January 2018.

      Fixed-income yields fell sharply during the six-month period due to
      investors' concerns over how U.S.-China trade tensions might hurt the
      already slowing global economy. Global central banks also reacted to trade
      concerns as the Fed, after raising interest rates four times in 2018,
      including in December, pivoted on monetary policy and indicated that it
      would pause on further rate increases. As the period progressed, the Fed
      took its easing tone one step further by hinting at one or two potential
      interest-rate cuts over the remainder of 2019. The European Central Bank
      also announced some accommodative measures in response to slowing global
      economic data and trade concerns.

4 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



      In late March, the Treasury yield curve inverted for the first time since
      2007, as long-term rates declined and the curve had a negative slope.
      Historically, an inverted curve often has been a leading indicator of an
      economic downturn.

      During the six-month period, the municipal bond market benefited from
      steady investor demand as inflows to tax-free mutual funds surged and
      remained strong. As noted earlier, the federal tax reform legislation
      passed in December 2017 continued to exert a significant impact on the
      municipal bond market over the six-month period. The revisions to the tax
      code effective in January 2018 included treating investors' interest
      income received on advance refunding bonds issued after December 31, 2017,
      as taxable income. (An advance refunding bond is issued to retire, or
      pre-refund, another outstanding bond more than 90 days in advance of the
      original bond's maturity date.) Prior to the change in the tax law,
      municipalities traditionally used advance refundings to refinance debt at
      lower rates and to delay repayment of principal. The revised law has
      effectively removed approximately one-quarter of the prior municipal
      supply from the tax-exempt marketplace, which in turn has helped to boost
      tax-free bond prices. In addition, the concurrently enacted federal limits
      on state and local tax (SALT) deductions has dramatically increased demand
      for municipal investments in high-tax states.

      State and local governments enjoyed strong tax collections and revenues
      over the six-month period, but reduced federal spending on infrastructure
      has forced municipalities to finance more of their own infrastructure
      projects. However, much of the spending has been cash-based rather than
      done with municipal financing, due to state officials' concerns that the
      U.S. economy could be on the verge of a recession, and that has negatively
      affected municipal supply. Lastly, while the tax-exempt bond market
      continued to receive support from demand by its traditional investors, it
      also benefited from other factors, including interest by non-traditional
      buyers, such as global insurance companies looking for relative safety, a
      low default rate, and attractive bond valuations versus taxable bonds.

Q     What were your principal investment strategies in managing the Fund's
      portfolio during the six-month period ended June 30, 2019?

A     Our focus remained the same during the six-month period, which is to keep
      the portfolio fully invested in securities that have a variety of coupon
      structures in the longer-term municipal market, as those investments offer
      higher yield potential in the tax-exempt marketplace. We believe that,
      over the long term, our broadly diversified* strategy positions the Fund
      for strong performance relative to its benchmark and its municipal fund
      peers. The Fund also continues to have a strong focus on sectors that are
      vital to

*     Diversification does not assure a profit nor protect against loss.

                 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 5



      the national as well as regional economies. The sectors include health
      care/hospitals, public and private education, power/energy, and
      transportation.

      During the period, we maintained our emphasis on overall portfolio
      quality. As of June 30, 2019, roughly 30% of the portfolio's holdings were
      rated "AAA" or the equivalent, and approximately 83% were rated "A" or
      better. In addition, the Fund's investments remain broadly diversified
      across a wide range of municipal bond sectors.

Q     What were the most significant contributors to and detractors from the
      Fund's benchmark-relative performance during the six-month period ended
      June 30, 2019?

A     The Fund's investments in education bonds from New York State, sales
      tax/motor vehicle excise tax bonds from Puget Sound (Washington), and
      Massachusetts-based health care/education bonds were among the most
      significant contributors to benchmark-relative returns during the
      six-month period.

      Individual detractors from the Fund's benchmark-relative performance
      included pollution control bonds from Missouri, industrial revenue bonds
      from Arizona, and Texas education bonds.

Q     What was the status of the Fund's distributions to shareholders during the
      six-month period ended June 30, 2019?

A     The Fund's distributions** remained stable over the six-months, beginning
      and ending the period at 0.34 cents per share between January 2019 and
      June 2019.

Q     What is your outlook as we move into the second half of the Fund's fiscal
      year?

A     We believe the Fed's monetary policy should become an increasingly
      important determinant of the performance of the municipal bond market
      going forward. In the past, once the Fed has embarked on a policy course,
      whether tightening credit conditions or becoming more accommodative, it
      typically has not reversed course quickly. We appear to be in an
      environment of declining interest rates for the foreseeable near-term
      future, with occasional geopolitical or economic disruptions.

      In addition, it seems that the current supply/demand imbalance for
      tax-exempt bonds will continue. That, in turn, should support municipal
      bond prices. In light of the growing evidence of a slowdown in the global
      economy, we look for more and more domestic and international investors to
      participate in the municipal bond market.

**    Distributions are not guaranteed.

6 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



      We continue to maintain the Fund's duration at approximately one year
      longer than that of the Bloomberg Barclays Index, due to the attractive
      yields available at the longer end of the municipal yield curve. (Duration
      is a measure of the sensitivity of the price, or the value of principal,
      of a fixed-income investment to a change in interest rates, expressed as a
      number of years.)

      We will continue to hold select, longer-term tax-exempt bonds in the
      Fund's portfolio, bonds that we believe have the strongest opportunity to
      perform well over time. We will also continue to monitor the Fund's
      holdings to ensure continued strength in credit quality as well as the
      timely payment of principal and interest. The Fund remains broadly
      diversified, and the vast majority of the portfolio's holdings are in
      bonds with dedicated revenue streams, which we also continue to monitor
      closely.

      We believe that Pioneer AMT-Free Municipal Fund continues to be a suitable
      vehicle for appropriate, long-term investors seeking income that is free
      from federal income taxes.

Please refer to the Schedule of Investments on pages 17-32 for a full listing
of Fund securities.

All investments are subject to risk, including the possible loss of principal.
In the past several years, financial markets have experienced increased
volatility, depressed valuations, decreased liquidity and heightened
uncertainty. These conditions may continue, recur, worsen or spread.

When interest rates rise, the prices of fixed-income securities in the Fund
will generally fall. Conversely, when interest rates fall, the prices of
fixed-income securities in the Fund will generally rise.

Investments in the Fund are subject to possible loss due to the financial
failure of issuers of underlying securities and their inability to meet their
debt obligations.

At times, the Fund's investments may represent industries or industry sectors
that are interrelated or have common risks, making the Fund more susceptible to
any economic, political, or regulatory developments or other risks affecting
those industries and sectors.

The value of municipal securities can be adversely affected by changes in the
financial condition of municipal issuers, lower revenues, and regulatory and
political developments.

                 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 7



A portion of income may be subject to local, state, federal and/or alternative
minimum tax. Capital gains, if any, are subject to capital gains tax.

These risks may increase share price volatility.

Before investing, consider the product's investment objectives, risks, charges
and expenses. Contact your advisor or Amundi Pioneer Asset Management, Inc.,
for a prospectus or summary prospectus containing this information. Read it
carefully.

Any information in this shareholder report regarding market or economic trends
or the factors influencing the Fund's historical or future performance are
statements of opinion as of the date of this report. Past performance is no
guarantee of future results.

8 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



Portfolio Summary | 6/30/19

Sector Distribution
--------------------------------------------------------------------------------
(As a percentage of total investments)*

[THE FOLLOWING DATA WAS REPRESENTED AS A PIE CHART IN THE PRINTED MATERIAL]



                                                                        
General Obligation                                                         29.4%
Education Revenue                                                          27.6%
Health Revenue                                                             13.1%
Transportation Revenue                                                      7.3%
Development Revenue                                                         7.0%
Tobacco Revenue                                                             6.4%
Water Revenue                                                               5.7%
Utilities Revenue                                                           2.3%
Other Revenue                                                               0.5%
Pollution Control Revenue                                                   0.5%
Power Revenue                                                               0.1%
Facilities Revenue                                                          0.1%


State Diversification
--------------------------------------------------------------------------------
(As a percentage of total investments)*

[THE FOLLOWING DATA WAS REPRESENTED AS A PIE CHART IN THE PRINTED MATERIAL]



                                                                       
Massachusetts                                                             20.43%
Texas                                                                      9.19%
Virginia                                                                   7.51%
California                                                                 7.48%
Florida                                                                    7.10%
Washington                                                                 6.20%
Pennsylvania                                                               4.69%
New York                                                                   4.00%
Illinois                                                                   3.22%
North Carolina                                                             3.04%
Maryland                                                                   2.73%
Georgia                                                                    2.51%
Oregon                                                                     2.28%
Minnesota                                                                  2.17%
Ohio                                                                       1.77%
Arizona                                                                    1.56%
Colorado                                                                   1.52%
Rhode Island                                                               1.48%
Mississippi                                                                1.17%
District of Columbia                                                       1.13%
New Jersey                                                                 1.11%
New Hampshire                                                              1.06%
Maine                                                                      0.96%
Missouri                                                                   0.78%
Michigan                                                                   0.76%
South Carolina                                                             0.62%
Louisiana                                                                  0.59%
Utah                                                                       0.59%
Connecticut                                                                0.44%
North Dakota                                                               0.43%
Delaware                                                                   0.43%
Puerto Rico                                                                0.31%
Indiana                                                                    0.28%
Oklahoma                                                                   0.24%
Nebraska                                                                   0.17%
Other                                                                      0.05%


                 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 9



Portfolio Summary | 6/30/19 (continued)

10 Largest Holdings
--------------------------------------------------------------------------------
(As a percentage of total investments)*



                                                                                               
 1. Massachusetts Health & Educational Facilities Authority, Massachusetts
    Institute of Technology, Series K, 5.5%, 7/1/32                                               2.00%
-------------------------------------------------------------------------------------------------------
 2. Tobacco Settlement Financing Corp., Senior, Series B-1, 5.0%, 6/1/47                          1.53
-------------------------------------------------------------------------------------------------------
 3. Central Puget Sound Regional Transit Authority, Series S-1, 5.0%, 11/1/46                     1.32
-------------------------------------------------------------------------------------------------------
 4. New York State Dormitory Authority, Columbia University, Series A-2, 5.0%, 10/1/46            1.22
-------------------------------------------------------------------------------------------------------
 5. Virginia Public Building Authority, Series A, 3.0%, 8/1/38                                    1.21
-------------------------------------------------------------------------------------------------------
 6. Massachusetts Development Finance Agency, Broad Institute, 4.0%, 4/1/41                       1.17
-------------------------------------------------------------------------------------------------------
 7. University of Virginia, Series A-1, 4.0%, 4/1/45                                              1.10
-------------------------------------------------------------------------------------------------------
 8. State of Washington, Series 2015-D, 5.0%, 7/1/30                                              1.03
-------------------------------------------------------------------------------------------------------
 9. Golden State Tobacco Securitization Corp., Asset-Backed, Series A-2, 5.0%, 6/1/47             1.01
-------------------------------------------------------------------------------------------------------
10. State of Florida, Department Transportation Right of Way, 4.0%, 7/1/39                        1.00
-------------------------------------------------------------------------------------------------------


*     Excludes temporary cash investments and all derivative contracts except
      for options purchased. The Fund is actively managed, and current holdings
      may be different. The holdings listed should not be considered
      recommendations to buy or sell any securities.

10 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



Prices and Distributions | 6/30/19

Net Asset Value per Share
--------------------------------------------------------------------------------



--------------------------------------------------------------------------------
     Class                6/30/19                  12/31/18
--------------------------------------------------------------------------------
                                              
      A                    $14.86                   $14.23
--------------------------------------------------------------------------------
      C                    $14.74                   $14.11
--------------------------------------------------------------------------------
      Y                    $14.83                   $14.19
--------------------------------------------------------------------------------


Distributions per Share: 1/1/19 - 6/30/19
--------------------------------------------------------------------------------



--------------------------------------------------------------------------------
                 Net Investment       Short-Term          Long-Term
     Class         Income*           Capital Gains       Capital Gains
--------------------------------------------------------------------------------
                                                    
      A            $0.2040               $ --                $ --
--------------------------------------------------------------------------------
      C            $0.1485               $ --                $ --
--------------------------------------------------------------------------------
      Y            $0.2224               $ --                $ --
--------------------------------------------------------------------------------


Index Definition
--------------------------------------------------------------------------------
The Bloomberg Barclays Municipal Bond Index is an unmanaged, broad measure of
the municipal bond market. Index returns are calculated monthly, assume
reinvestment of dividends and, unlike Fund returns, do not reflect any fees,
expenses or sales charges. It is not possible to invest directly in an index.

The index defined here pertains to the "Value of $10,000 Investment" and "Value
of $5 Million Investment" charts shown on pages 12-14.

*     Dividends per share may not reflect the amounts reported in the financial
      statements due to the last business day of the reporting period falling on
      a holiday weekend. Dividends are not guaranteed.

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 11



Performance Update | 6/30/19                                      Class A Shares

Investment Returns
--------------------------------------------------------------------------------
The mountain chart on the right shows the change in value of a $10,000
investment made in Class A shares of Pioneer AMT-Free Municipal Fund at public
offering price during the periods shown, compared to that of the Bloomberg
Barclays Municipal Bond Index.



Average Annual Total Returns
(As of June 30, 2019)
------------------------------------------------------
                 Net         Public        BBG
                 Asset       Offering      Barclays
                 Value       Price         Municipal
Period           (NAV)       (POP)         Bond Index
------------------------------------------------------
                                  
10 years         5.96%       5.47%         4.72%
5 years          4.08        3.13          3.64
1 year           6.65        1.85          6.71
------------------------------------------------------


Expense Ratio
(Per prospectus dated May 1, 2019)
------------------------------------------------------
Gross
------------------------------------------------------

0.81%
------------------------------------------------------


[THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL]

Value of $10,000 Investment



                                      Bloomberg Barclays
                 Pioneer AMT-Free     Municipal Bond
                 Municipal Fund       Index
                                
6/09             $ 9,550              $10,000
6/10             $10,914              $10,961
6/11             $11,227              $11,342
6/12             $12,788              $12,465
6/13             $12,926              $12,494
6/14             $13,947              $13,262
6/15             $14,497              $13,660
6/16             $15,980              $14,705
6/17             $15,737              $14,633
6/18             $15,974              $14,862
6/19             $17,036              $15,859


Call 1-800-225-6292 or visit www.amundipioneer.com/us for the most recent
month-end performance results. Current performance may be lower or higher than
the performance data quoted.

The performance data quoted represents past performance, which is no guarantee
of future results. Investment return and principal value will fluctuate, and
shares, when redeemed, may be worth more or less than their original cost.

NAV results represent the percent change in net asset value per share. POP
returns reflect deduction of maximum 4.50% sales charge. NAV returns would have
been lower had sales charges been reflected. All results are historical and
assume the reinvestment of dividends and capital gains. Other share classes are
available for which performance and expenses will differ.

Performance results reflect any applicable expense waivers in effect during the
periods shown. Without such waivers Fund performance would be lower. Waivers
may not be in effect for all funds. Certain fee waivers are contractual through
a specified period. Otherwise, fee waivers can be rescinded at any time. See
the prospectus and financial statements for more information.

The performance table and graph do not reflect the deduction of fees and taxes
that a shareowner would pay on Fund distributions or the redemption of Fund
shares.

Please refer to the financial highlights for a more current expense ratio.

12 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



Performance Update | 6/30/19                                      Class C Shares

Investment Returns
--------------------------------------------------------------------------------
The mountain chart on the right shows the change in value of a $10,000
investment made in Class C shares of Pioneer AMT-Free Municipal Fund during the
periods shown, compared to that of the Bloomberg Barclays Municipal Bond
Index.



Average Annual Total Returns
(As of June 30, 2019)
------------------------------------------------------
                                           BBG
                                           Barclays
                  If         If            Municipal
Period            Held       Redeemed      Bond Index
------------------------------------------------------
                                  
10 years          5.15%      5.15%         4.72%
5 years           3.30       3.30          3.64
1 year            5.90       5.90          6.71
------------------------------------------------------


Expense Ratio
(Per prospectus dated May 1, 2019)
------------------------------------------------------
Gross
------------------------------------------------------

1.57%
------------------------------------------------------


[THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL]

Value of $10,000 Investment



                                      Bloomberg Barclays
                 Pioneer AMT-Free     Municipal Bond
                 Municipal Fund       Index
                                
6/09             $10,000              $10,000
6/10             $11,335              $10,961
6/11             $11,569              $11,342
6/12             $13,076              $12,465
6/13             $13,116              $12,494
6/14             $14,048              $13,262
6/15             $14,483              $13,660
6/16             $15,856              $14,705
6/17             $15,493              $14,633
6/18             $15,606              $14,862
6/19             $16,526              $15,859


Call 1-800-225-6292 or visit www.amundipioneer.com/us for the most recent
month-end performance results. Current performance may be lower or higher than
the performance data quoted.

The performance data quoted represents past performance, which is no guarantee
of future results. Investment return and principal value will fluctuate, and
shares, when redeemed, may be worth more or less than their original cost.

Class C shares held for less than one year are also subject to a 1% contingent
deferred sales charge (CDSC). "If Held" results represent the percent change in
net asset value per share. NAV returns would have been lower had sales charges
been reflected. All results are historical and assume the reinvestment of
dividends and capital gains. Other share classes are available for which
performance and expenses will differ.

Performance results reflect any applicable expense waivers in effect during the
periods shown. Without such waivers Fund performance would be lower. Waivers
may not be in effect for all funds. Certain fee waivers are contractual through
a specified period. Otherwise, fee waivers can be rescinded at any time. See
the prospectus and financial statements for more information.

The performance table and graph do not reflect the deduction of fees and taxes
that a shareowner would pay on Fund distributions or the redemption of Fund
shares.

Please refer to the financial highlights for a more current expense ratio.

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 13



Performance Update | 6/30/19                                      Class Y Shares

Investment Returns
--------------------------------------------------------------------------------
The mountain chart on the right shows the change in value of a $5 million
investment made in Class Y shares of Pioneer AMT-Free Municipal Fund during the
periods shown, compared to that of the Bloomberg Barclays Municipal Bond
Index.



Average Annual Total Returns
(As of June 30, 2019)
------------------------------------------------------
                 Net          BBG
                 Asset        Barclays
                 Value        Municipal
Period           (NAV)        Bond Index
------------------------------------------------------
                        
10 years         6.30%        4.72%
5 years          4.39         3.64
1 year           7.01         6.71
------------------------------------------------------


Expense Ratio
(Per prospectus dated May 1, 2019)
------------------------------------------------------
         Gross        Net
------------------------------------------------------
                   
         0.65%        0.55%
------------------------------------------------------


[THE FOLLOWING DATA WAS REPRESENTED AS A MOUNTAIN CHART IN THE PRINTED MATERIAL]

Value of $5 Million Investment



                                      Bloomberg Barclays
                 Pioneer AMT-Free     Municipal Bond
                 Municipal Fund       Index
                                
6/09             $5,000,000           $5,000,000
6/10             $5,765,822           $5,480,596
6/11             $5,944,607           $5,671,062
6/12             $6,789,235           $6,232,519
6/13             $6,871,031           $6,247,243
6/14             $7,429,250           $6,631,033
6/15             $7,748,532           $6,829,913
6/16             $8,565,052           $7,352,584
6/17             $8,455,790           $7,316,749
6/18             $8,604,427           $7,431,205
6/19             $9,207,507           $7,929,563


Call 1-800-225-6292 or visit www.amundipioneer.com/us for the most recent
month-end performance results. Current performance may be lower or higher than
the performance data quoted.

The performance data quoted represents past performance, which is no guarantee
of future results. Investment return and principal value will fluctuate, and
shares, when redeemed, may be worth more or less than their original cost.

Class Y shares are not subject to sales charges and are available for limited
groups of eligible investors, including institutional investors. All results
are historical and assume the reinvestment of dividends and capital gains.
Other share classes are available for which performance and expenses will
differ.

Performance results reflect any applicable expense waivers in effect during the
periods shown. Without such waivers Fund performance would be lower. Waivers
may not be in effect for all funds. Certain fee waivers are contractual through
a specified period. Otherwise, fee waivers can be rescinded at any time. See
the prospectus and financial statements for more information.

The net expense ratio reflects the contractual expense limitation currently in
effect through May 1, 2020, for Class Y shares. There can be no assurance that
Amundi Pioneer will extend the expense limitation beyond such time. Please see
the prospectus and financial statements for more information.

The performance table and graph do not reflect the deduction of fees and taxes
that a shareowner would pay on Fund distributions or the redemption of Fund
shares.

Please refer to the financial highlights for a more current expense ratio.

14 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



Comparing Ongoing Fund Expenses

As a shareowner in the Fund, you incur two types of costs:

(1)   ongoing costs, including management fees, distribution and/or service
      (12b-1) fees, and other Fund expenses; and

(2)   transaction costs, including sales charges (loads) on purchase payments.

This example is intended to help you understand your ongoing expenses (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 at the beginning of the Fund's latest six-month period and held
throughout the six months.

Using the Tables
--------------------------------------------------------------------------------
Actual Expenses

The first table below provides information about actual account values and
actual expenses. You may use the information in this table, together with the
amount you invested, to estimate the expenses that you paid over the period as
follows:

(1)   Divide your account value by $1,000
      Example: an $8,600 account value (divided by) $1,000 = 8.6

(2)   Multiply the result in (1) above by the corresponding share class's number
      in the third row under the heading entitled "Expenses Paid During Period"
      to estimate the expenses you paid on your account during this period.

Expenses Paid on a $1,000 Investment in Pioneer AMT-Free Municipal Fund

Based on actual returns from January 1, 2019 through June 30, 2019.



--------------------------------------------------------------------------------
Share Class                        A                 C                 Y
--------------------------------------------------------------------------------
                                                           
Beginning Account               $1,000.00         $1,000.00         $1,000.00
Value on 1/1/19
--------------------------------------------------------------------------------
Ending Account                  $1,059.00         $1,055.40         $1,061.20
Value on 6/30/19
--------------------------------------------------------------------------------
Expenses Paid                       $4.19             $8.00             $2.81
During Period*
--------------------------------------------------------------------------------


*     Expenses are equal to the Fund's annualized net expense ratio of 0.82%,
      1.57% and 0.55% for Class A, Class C and Class Y shares, respectively,
      multiplied by the average account value over the period, multiplied by
      181/365 (to reflect the one-half year period).

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 15



Comparing Ongoing Fund Expenses

Hypothetical Example for Comparison Purposes

The table below 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 tables are meant to highlight your
ongoing costs only and do not reflect any transaction costs, such as sales
charges (loads) that are charged at the time of the transaction. Therefore, the
table below 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 transaction costs were included, your costs would have been higher.

Expenses Paid on a $1,000 Investment in Pioneer AMT-Free Municipal Fund

Based on a hypothetical 5% per year return before expenses, reflecting the
period from January 1, 2019 through June 30, 2019.



--------------------------------------------------------------------------------
Share Class                        A                 C                 Y
--------------------------------------------------------------------------------
                                                           
Beginning Account               $1,000.00         $1,000.00         $1,000.00
Value on 1/1/19
--------------------------------------------------------------------------------
Ending Account                  $1,020.73         $1,017.01         $1,022.07
Value on 6/30/19
--------------------------------------------------------------------------------
Expenses Paid                       $4.11             $7.85             $2.76
During Period*
--------------------------------------------------------------------------------


*     Expenses are equal to the Fund's annualized net expense ratio of 0.82%,
      1.57% and 0.55% for Class A, Class C and Class Y shares, respectively,
      multiplied by the average account value over the period, multiplied by
      181/365 (to reflect the one-half year period).

16 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



Schedule of Investments | 6/30/19 (unaudited)



------------------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                                       Value
------------------------------------------------------------------------------------------------------------
                                                                                        
                          UNAFFILIATED ISSUERS -- 98.3%
                          MUNICIPAL BONDS -- 98.3% of Net Assets(a)
                          Arizona -- 1.5%
    5,680,000             Arizona Department of Transportation State Highway
                          Fund Revenue, 5.0%, 7/1/30                                          $    6,920,853
      135,000(b)          City of Mesa, Utility System Revenue, 3.25%, 7/1/29                        146,584
    9,865,000             City of Mesa, Utility System Revenue, 3.25%, 7/1/29                     10,452,066
        9,000             County of Pima, Industrial Development Authority,
                          Arizona Charter Schools Project, Series C,
                          6.75%, 7/1/31                                                                9,106
    1,000,000             Maricopa County Pollution Control Corp., Southern
                          California Education Co., Series A, 5.0%, 6/1/35                         1,021,550
                                                                                              --------------
                          Total Arizona                                                       $   18,550,159
------------------------------------------------------------------------------------------------------------
                          California -- 7.4%
   10,000,000(c)          Alameda Corridor Transportation Authority, California
                          Revenue Capital Appreciation Senior Lien, Series A,
                          10/1/31 (NATL Insured)                                              $    7,325,000
   12,595,000(c)          Anaheim Public Financing Authority, Public
                          Improvements Project, Series C, 9/1/36
                          (AGM Insured)                                                            7,390,746
   20,000,000(c)          California County Tobacco Securitization Agency,
                          Capital Appreciation, Stanislaus County,
                          Subordinated, Series A, 6/1/46                                           3,627,800
   36,350,000(c)          California County Tobacco Securitization Agency,
                          Capital Appreciation, Stanislaus County,
                          Subordinated, Series D, 6/1/55                                           1,242,079
    6,400,000             California Educational Facilities Authority, Stanford
                          University, Series U-A, 5.0%, 5/1/45                                     9,247,104
    3,575,000(b)          California Statewide Communities Development
                          Authority, Sutter Health, Series A, 6.0%, 8/15/42                        3,771,339
    5,000,000             City of San Francisco, Public Utilities Commission
                          Water Revenue, Series A, 4.0%, 11/1/33                                   5,471,200
    7,000,000             City of San Francisco, Public Utilities Commission
                          Water Revenue, Series A, 4.0%, 11/1/34                                   7,641,270
    5,000,000(d)          Coast Community College District, Election 2012,
                          Series D, 5.0%, 8/1/31                                                   6,239,500
   12,000,000             Golden State Tobacco Securitization Corp.,
                          Asset-Backed, Series A-2, 5.0%, 6/1/47                                  12,000,000
    3,000,000             Long Beach Bond Finance Authority, Series A,
                          5.5%, 11/15/37                                                           4,038,390
    2,180,000(d)          Pomona Unified School District, Series A, 6.55%,
                          8/1/29 (NATL Insured)                                                    2,845,336
    5,000,000(d)          San Diego Unified School District, Series R2,
                          0.0%, 7/1/40                                                             4,693,800
    3,500,000             San Francisco City & County Airport Commission-
                          San Francisco International Airport, Series B,
                          5.0%, 5/1/47                                                             4,103,435
    1,500,000(d)          San Jose Evergreen Community College District,
                          Election of 2010, Series A, 5.0%, 8/1/41                                 1,651,635


The accompanying notes are an integral part of these financial statements.

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 17



Schedule of Investments | 6/30/19 (unaudited) (continued)



------------------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                                       Value
------------------------------------------------------------------------------------------------------------
                                                                                        
                          California -- (continued)
    1,500,000(b)          Santa Cruz County Redevelopment Agency, Live
                          Oak / Soquel Community Improvement, Series A,
                          6.625%, 9/1/29                                                      $    1,513,875
    5,000,000             University of California, Series AV, 5.0%, 5/15/35                       6,047,000
                                                                                              --------------
                          Total California                                                    $   88,849,509
------------------------------------------------------------------------------------------------------------
                          Colorado -- 1.5%
    2,500,000             Regional Transportation District, Denver Trans
                          Partners, 6.0%, 1/15/26                                             $    2,585,225
    1,250,000             Regional Transportation District, Denver Trans
                          Partners, 6.0%, 1/15/34                                                  1,286,700
    1,000,000             Regional Transportation District, Denver Trans
                          Partners, 6.0%, 1/15/41                                                  1,026,310
    2,000,000             Regional Transportation District, Denver Trans
                          Partners, 6.5%, 1/15/30                                                  2,073,840
    5,000,000             University of Colorado, Series A-2, 4.0%, 6/1/38                         5,565,000
    5,000,000             University of Colorado, Series A-2, 4.0%, 6/1/39                         5,560,400
                                                                                              --------------
                          Total Colorado                                                      $   18,097,475
------------------------------------------------------------------------------------------------------------
                          Connecticut -- 0.4%
    3,000,000(d)          Metropolitan District, 3.0%, 3/1/29                                 $    3,082,140
    2,000,000             Mohegan Tribal Finance Authority, Connecticut Tribal
                          Economic Development, 7.0%, 2/1/45 (144A)                                2,082,100
                                                                                              --------------
                          Total Connecticut                                                   $    5,164,240
------------------------------------------------------------------------------------------------------------
                          Delaware -- 0.4%
    4,975,000             Delaware State Economic Development Authority,
                          Facility-Indian River Power, 5.375%, 10/1/45                        $    5,128,678
                                                                                              --------------
                          Total Delaware                                                      $    5,128,678
------------------------------------------------------------------------------------------------------------
                          District of Columbia -- 1.1%
    10,000,000            District of Columbia Tobacco Settlement Financing
                          Corp., Asset-Backed, 6.75%, 5/15/40                                 $   10,537,500
   84,000,000(c)          District of Columbia Tobacco Settlement Financing
                          Corp., Asset-Backed, Series C, 6/15/55                                   2,845,920
                                                                                              --------------
                          Total District of Columbia                                          $   13,383,420
------------------------------------------------------------------------------------------------------------
                          Florida -- 7.0%
    1,000,000             Central Florida Expressway Authority, 5.0%, 7/1/39                  $    1,182,900
    2,000,000             Central Florida Expressway Authority, Senior Lien,
                          5.0%, 7/1/38                                                             2,343,320
    2,615,000             City of Tampa, Baycare Health Care, Series A,
                          5.0%, 11/15/46                                                           2,991,142
    6,145,000             County of Hillsborough FL, 3.0%, 8/1/41                                  6,020,134
    4,500,000             County of Hillsborough, Utility Revenue, 3.0%, 8/1/37                    4,621,545
    5,000,000(b)          County of Miami-Dade, Aviation Revenue, Series B,
                          5.5%, 10/1/41                                                            5,055,900
    2,500,000             County of Orange, Water Utility System Revenue,
                          3.0%, 10/1/32                                                            2,576,725


The accompanying notes are an integral part of these financial statements.

18 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19





------------------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                                       Value
------------------------------------------------------------------------------------------------------------
                                                                                        
                          Florida -- (continued)
    4,645,000             County of Orange, Water Utility System Revenue,
                          3.0%, 10/1/34                                                       $    4,760,289
    3,000,000             Escambia County Health Facilities Authority, Baptist
                          Hospital, Inc. Project, Series A, 6.0%, 8/15/36                          3,142,020
    1,390,000             Florida Development Finance Corp., Renaissance
                          Charter School, Series A, 6.0%, 9/15/30                                  1,435,592
    5,000,000             Florida's Turnpike Enterprise, Department
                          Transportation, Series A, 4.0%, 7/1/30                                   5,479,800
    6,850,000             JEA Water & Sewer System Revenue, Series A,
                          4.0%, 10/1/34                                                            7,584,320
    3,400,000(b)          St. Johns County Industrial Development Authority,
                          Presbyterian Retirement, Series A, 6.0%, 8/1/45                          3,569,490
    8,000,000(d)          State of Florida, Capital Outlay, Series A,
                          3.0%, 6/1/29                                                             8,380,240
    8,000,000(d)          State of Florida, Capital Outlay, Series C,
                          3.0%, 6/1/30                                                             8,422,080
    4,645,000(d)          State of Florida, Department Transportation Right
                          of Way, 3.25%, 7/1/37                                                    4,843,620
   10,660,000(d)          State of Florida, Department Transportation Right
                          of Way, 4.0%, 7/1/39                                                    11,840,488
                                                                                              --------------
                          Total Florida                                                       $   84,249,605
------------------------------------------------------------------------------------------------------------
                          Georgia -- 2.5%
    8,000,000(d)          City of Atlanta, Public Improvement, 4.5%, 12/1/29                  $    9,140,400
    2,040,000(d)          County of Fulton, Library Bond, 3.25%, 7/1/37                            2,111,441
    2,870,000(d)          County of Fulton, Library Bond, 3.5%, 7/1/39                             2,982,963
    4,790,000(d)          County of Fulton, Library Bond, 4.0%, 7/1/40                             5,210,754
    2,000,000             Main Street Natural Gas, Inc., Series A,
                          4.0%, 5/15/39                                                            2,085,160
    5,000,000             Metropolitan Atlanta Rapid Transit Authority,
                          Series C, 3.5%, 7/1/38                                                   5,204,400
    2,750,000             Private Colleges & Universities Authority, Emory
                          University, Series A, 5.0%, 10/1/43                                      3,086,160
                                                                                              --------------
                          Total Georgia                                                       $   29,821,278
------------------------------------------------------------------------------------------------------------
                          Illinois -- 3.2%
    1,000,000             Illinois Finance Authority, American Water Capital
                          Corp., Project, 5.25%, 5/1/40                                       $    1,016,070
    1,000,000             Illinois Finance Authority, Art Institute Of Chicago,
                          4.0%, 3/1/38                                                             1,084,040
    1,500,000             Illinois Finance Authority, Art Institute Of Chicago,
                          5.0%, 3/1/30                                                             1,786,005
    5,000,000             Illinois Finance Authority, Centegra Health System,
                          Series A, 5.0%, 9/1/42                                                   5,597,500
    1,500,000             Illinois Finance Authority, Northwestern Memorial
                          Healthcare, 4.0%, 7/15/36                                                1,659,645
    2,175,000             Illinois Finance Authority, Northwestern Memorial
                          Healthcare, 4.0%, 7/15/37                                                2,397,720


The accompanying notes are an integral part of these financial statements.

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 19



Schedule of Investments | 6/30/19 (unaudited) (continued)



------------------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                                       Value
------------------------------------------------------------------------------------------------------------
                                                                                        
                          Illinois -- (continued)
    3,000,000             Illinois Finance Authority, Northwestern Memorial
                          Healthcare, 4.0%, 7/15/47                                           $    3,212,280
    8,540,000             Illinois Finance Authority, Presence Health Network,
                          Series C, 5.0%, 2/15/33                                                 10,168,578
    1,000,000             Illinois Finance Authority, Presence Health Network,
                          Series C, 5.0%, 2/15/36                                                  1,181,110
    5,000,000(b)          Illinois Finance Authority, Roosevelt University Project,
                          6.5%, 4/1/39                                                             5,065,850
    4,130,000(e)          Metropolitan Pier & Exposition Authority, Mccormick
                          Place Convention, 7.0%, 7/1/26                                           4,999,406
                                                                                              --------------
                          Total Illinois                                                      $   38,168,204
------------------------------------------------------------------------------------------------------------
                          Indiana -- 0.3%
    3,000,000             Indiana University, Series A, 4.0%, 6/1/42                          $    3,208,080
       85,000             Indianapolis Local Public Improvement Bond Bank,
                          Series B, 6.0%, 1/10/20                                                     86,864
                                                                                              --------------
                          Total Indiana                                                       $    3,294,944
------------------------------------------------------------------------------------------------------------
                          Louisiana -- 0.6%
    6,000,000             Jefferson Parish Hospital Service District No. 2, East
                          Jefferson General Hospital, 6.375%, 7/1/41                          $    5,999,220
      400,000(b)          Louisiana State Citizens Property Insurance Corp.,
                          5.0%, 6/1/24                                                               441,392
      500,000(b)          Louisiana State Citizens Property Insurance Corp.,
                          5.0%, 6/1/24 (AGM Insured)                                                 553,210
                                                                                              --------------
                          Total Louisiana                                                     $    6,993,822
------------------------------------------------------------------------------------------------------------
                          Maine -- 1.0%
    4,500,000             Maine Health & Higher Educational Facilities Authority,
                          Maine General Medical Center, 6.75%, 7/1/36                         $    4,853,475
    3,040,000             Maine Health & Higher Educational Facilities Authority,
                          Maine General Medical Center, 6.95%, 7/1/41                              3,287,517
    2,745,000             University of Maine, 5.0%, 3/1/25 (AGM Insured)                          3,291,831
                                                                                              --------------
                          Total Maine                                                         $   11,432,823
------------------------------------------------------------------------------------------------------------
                          Maryland -- 2.7%
      900,000(f)          Maryland Economic Development Corp., Senior
                          Lien-Chesapeake Bay, Series A, 5.0%, 12/1/16                        $      562,500
      400,000(f)          Maryland Economic Development Corp., Senior
                          Lien-Chesapeake Bay, Series B, 5.0%, 12/1/16                               250,000
    6,250,000             Maryland Health & Higher Educational Facilities
                          Authority, Ascension Health, Series B, 5.0%, 11/15/51                    6,704,375
    5,000,000(d)          State of Maryland, Series A, 5.0%, 3/15/29                               6,174,250
    5,175,000(d)          Washington Suburban Sanitary Commission,
                          Consolidated Public Improvement, 3.0%, 6/1/35                            5,336,615
    5,180,000(d)          Washington Suburban Sanitary Commission,
                          Consolidated Public Improvement, 3.0%, 6/1/37                            5,310,277


The accompanying notes are an integral part of these financial statements.

20 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19





------------------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                                       Value
------------------------------------------------------------------------------------------------------------
                                                                                        
                          Maryland -- (continued)
    3,880,000(d)          Washington Suburban Sanitary Commission,
                          Consolidated Public Improvement, Second Series,
                          4.0%, 6/1/43                                                        $    4,102,518
    3,735,000(d)          Washington Suburban Sanitary Commission,
                          Consolidated Public Improvement, Second Series,
                          4.0%, 6/1/44                                                             3,946,028
                                                                                              --------------
                          Total Maryland                                                      $   32,386,563
------------------------------------------------------------------------------------------------------------
                          Massachusetts -- 20.1%
    3,485,000(d)          Cape Cod Regional Technical High School District,
                          School Project Loan Chapter 70 B, 4.0%, 11/15/37                    $    3,841,481
    3,485,000(d)          Cape Cod Regional Technical High School District,
                          School Project Loan Chapter 70 B, 4.0%, 11/15/38                         3,831,862
    1,475,000(d)          City of Attleboro, Municipal Purpose Loan,
                          3.125%, 2/15/35                                                          1,516,654
    1,520,000(d)          City of Attleboro, Municipal Purpose Loan,
                          3.25%, 2/15/36                                                           1,576,772
    1,565,000(d)          City of Attleboro, Municipal Purpose Loan,
                          3.25%, 2/15/37                                                           1,618,648
    1,055,000(d)          City of Beverly, 3.125%, 10/15/39                                        1,070,160
    2,000,000(d)          City of Boston, Series A, 5.0%, 3/1/39                                   2,486,240
    1,375,000(d)          City of Cambridge, Municipal Purpose Loan,
                          4.0%, 2/15/26                                                            1,649,092
    5,075,000(d)          City of Cambridge, Municipal Purpose Loan,
                          Series A, 3.0%, 2/15/35                                                  5,212,837
    1,300,000(d)          Concord & Carlisle Regional School District,
                          3.0%, 3/15/29                                                            1,332,370
    1,300,000(d)          Concord & Carlisle Regional School District,
                          3.0%, 3/15/31                                                            1,325,363
    1,300,000(d)          Concord & Carlisle Regional School District,
                          3.0%, 3/15/33                                                            1,319,773
    7,175,000(c)          Massachusetts Bay Transportation Authority,
                          Series A, 7/1/28                                                         5,880,630
    5,000,000(c)          Massachusetts Department of Transportation,
                          Series A, 1/1/28 (NATL Insured)                                          4,193,100
    4,200,000             Massachusetts Development Finance Agency,
                          Agency Williams College, Series P, 5.0%, 7/1/43                          4,720,422
    1,000,000             Massachusetts Development Finance Agency,
                          Babson College, 5.0%, 10/1/21                                            1,076,850
    1,000,000             Massachusetts Development Finance Agency,
                          Babson College, 5.0%, 10/1/22                                            1,073,580
    1,500,000             Massachusetts Development Finance Agency,
                          Berklee College Music, 5.0%, 10/1/35                                     1,788,195
    1,000,000             Massachusetts Development Finance Agency,
                          Berkshire Health System, Series G, 5.0%, 10/1/30                         1,060,710
    4,000,000             Massachusetts Development Finance Agency,
                          Boston University, Series X, 5.0%, 10/1/48                               4,461,960
   12,690,000             Massachusetts Development Finance Agency,
                          Broad Institute, 4.0%, 4/1/41                                           13,936,412


The accompanying notes are an integral part of these financial statements.

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 21



Schedule of Investments | 6/30/19 (unaudited) (continued)



------------------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                                       Value
------------------------------------------------------------------------------------------------------------
                                                                                        
                          Massachusetts -- (continued)
    2,000,000             Massachusetts Development Finance Agency,
                          Broad Institute, 5.0%, 4/1/37                                       $    2,400,160
    6,255,000(b)          Massachusetts Development Finance Agency, Broad
                          Institute, Inc., Series A, 5.375%, 4/1/41                                6,691,662
    1,000,000(b)          Massachusetts Development Finance Agency,
                          Foxborough Regional Charter School, Series A,
                          7.0%, 7/1/42                                                             1,056,650
    5,000,000             Massachusetts Development Finance Agency,
                          Harvard University, Series A, 4.0%, 7/15/36                              5,626,700
    1,000,000             Massachusetts Development Finance Agency,
                          Harvard University, Series A, 5.0%, 7/15/40                              1,395,760
    5,000,000             Massachusetts Development Finance Agency,
                          Lawrence General Hospital, Series A, 5.5%, 7/1/44                        5,304,850
    4,000,000             Massachusetts Development Finance Agency,
                          Lowell General Hospital, Series G, 5.0%, 7/1/44                          4,223,360
      400,000             Massachusetts Development Finance Agency,
                          Milford Regional Medical Center, Series F,
                          5.625%, 7/15/36                                                            432,044
      500,000             Massachusetts Development Finance Agency,
                          Milford Regional Medical Center, Series F,
                          5.75%, 7/15/43                                                             537,455
    2,000,000             Massachusetts Development Finance Agency,
                          Northeastern University, 4.0%, 10/1/35                                   2,073,120
      450,000             Massachusetts Development Finance Agency,
                          Northeastern University, Series A, 5.0%, 3/1/39                            506,844
    9,930,000             Massachusetts Development Finance Agency,
                          Partners Healthcare System, 5.0%, 7/1/31                                11,555,044
    2,700,000             Massachusetts Development Finance Agency,
                          Partners Healthcare System, Series O, 4.0%, 7/1/45                       2,820,177
    8,000,000             Massachusetts Development Finance Agency,
                          Partners Healthcare System, Series S, 4.0%, 7/1/35                       8,888,960
    5,000,000             Massachusetts Development Finance Agency,
                          Partner's Healthcare System, Series S-1,
                          4.0%, 7/1/41                                                             5,375,300
      400,000(b)          Massachusetts Development Finance Agency,
                          Tufts Medical, Series I, 6.75%, 1/1/36                                     432,344
      600,000(b)          Massachusetts Development Finance Agency,
                          Tufts Medication Center, Series, 6.75%, 1/1/36                             644,922
      125,000(b)          Massachusetts Development Finance Agency,
                          Tufts University, Series Q, 4.0%, 8/15/38                                  144,327
      875,000             Massachusetts Development Finance Agency,
                          Tufts University, Series Q, 4.0%, 8/15/38                                  933,958
    1,000,000             Massachusetts Development Finance Agency,
                          UMass Memorial, Series H, 5.125%, 7/1/26                                 1,072,210
    6,600,000             Massachusetts Development Finance Agency,
                          WGBH Educational Foundation, Series A, 5.75%,
                          1/1/42 (AMBAC Insured)                                                   9,809,448
    4,080,000(c)          Massachusetts Development Finance Agency,
                          WGBH Educational Foundation, Series B,
                          1/1/38 (AGC Insured)                                                     2,347,795


The accompanying notes are an integral part of these financial statements.

22 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19





------------------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                                       Value
------------------------------------------------------------------------------------------------------------
                                                                                        
                          Massachusetts -- (continued)
    1,585,000             Massachusetts Development Finance Agency,
                          Whitehead Institute Biomedical Research,
                          5.0%, 6/1/25                                                        $    1,687,090
      835,000             Massachusetts Development Finance Agency,
                          Woods Hole Oceanographic Institution, 5.0%, 6/1/38                       1,004,931
    1,000,000             Massachusetts Development Finance Agency,
                          Woods Hole Oceanographic Institution, 5.0%, 6/1/43                       1,185,640
      500,000             Massachusetts Development Finance Agency,
                          Woods Hole Oceanographic Institution, 5.0%, 6/1/48                         592,555
    2,500,000             Massachusetts Development Finance Agency,
                          Worcester Polytechnic Institute, 4.0%, 9/1/49                            2,620,725
    1,250,000             Massachusetts Development Finance Agency,
                          Worcester Polytechnic Institute, 5.0%, 9/1/50                            1,358,762
    6,000,000(g)          Massachusetts Health & Educational Facilities
                          Authority, Harvard University, Series R, 1.7%, 11/1/49                   6,000,000
    2,335,000(b)          Massachusetts Health & Educational Facilities
                          Authority, Massachusetts Eye And Ear Infirmary,
                          Series C, 5.375%, 7/1/35                                                 2,426,322
   16,950,000             Massachusetts Health & Educational Facilities
                          Authority, Massachusetts Institute of Technology,
                          Series K, 5.5%, 7/1/32                                                  23,771,867
    2,000,000             Massachusetts Health & Educational Facilities
                          Authority, Northeastern University, Series T-2,
                          4.125%, 10/1/37                                                          2,072,880
    1,000,000             Massachusetts Port Authority, Series B, 5.0%, 7/1/32                     1,103,970
    1,000,000             Massachusetts Port Authority, Series B, 5.0%, 7/1/33                     1,094,190
    3,000,000             Massachusetts Port Authority, Series C, 5.0%, 7/1/33                     3,447,540
    1,960,000(b)          Massachusetts State College Building Authority,
                          Series A, 5.0%, 5/1/28 (ST INTERCEPT Insured)                            2,158,332
    2,015,000             Massachusetts State College Building Authority.
                          Series A, 5.0%, 5/1/28 (ST INTERCEPT Insured)                            2,212,047
    2,420,000             Massachusetts Water Resources Authority, General,
                          Series B, 5.25%, 8/1/36 (AGM Insured)                                    3,495,859
    1,600,000(d)          Town of Lexington, Municipal Purpose Loan,
                          3.125%, 2/1/36                                                           1,723,712
    1,150,000(d)          Town of Lexington, Municipal Purpose Loan,
                          3.125%, 2/1/37                                                           1,228,568
    1,635,000(d)          Town of Lexington, Municipal Purpose Loan,
                          3.25%, 2/1/38                                                            1,752,933
    1,305,000(d)          Town of Nantucket, 2.0%, 12/15/27                                        1,350,688
    5,000,000(d)          Town of Natick, Municipal Purpose Loan,
                          4.0%, 7/15/37                                                            5,505,400
    1,955,000(d)          Town of Norwood, Municipal Purpose Loan,
                          2.125%, 7/15/30                                                          1,936,154
    2,000,000(d)          Town of Plymouth, Municipal Purpose Loan,
                          3.0%, 5/1/31                                                             2,073,140
    1,535,000(d)          Town of Plymouth, Municipal Purpose Loan,
                          3.375%, 5/1/32                                                           1,598,426


The accompanying notes are an integral part of these financial statements.

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 23



Schedule of Investments | 6/30/19 (unaudited) (continued)



------------------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                                       Value
------------------------------------------------------------------------------------------------------------
                                                                                        
                          Massachusetts -- (continued)
    1,265,000(d)          Town of Plymouth, Municipal Purpose Loan,
                          3.5%, 5/1/35                                                        $    1,317,624
    3,500,000(d)          Town of Plymouth, Municipal Purpose Loan,
                          3.5%, 5/1/44                                                             3,606,155
    2,635,000(d)          Town of Plymouth, Municipal Purpose Loan,
                          5.0%, 5/1/29                                                             3,240,866
    4,160,000(d)          Town of Stoughton, Municipal Purpose Loan,
                          3.0%, 10/15/37                                                           4,223,814
    1,000,000(d)          Town of Wellesley, Municipal Purpose Loan,
                          4.0%, 6/1/41                                                             1,074,220
    4,000,000(d)          Town of Wellesley, Municipal Purpose Loan,
                          4.0%, 6/1/45                                                             4,283,960
    4,500,000(d)          Town of Wilmington, School, 4.0%, 3/15/37                                4,690,800
    2,500,000             University of Massachusetts Building Authority,
                          Series 1, 5.0%, 11/1/39                                                  2,742,975
    4,160,000             Woods Hole Marthas Vineyard & Nantucket
                          Steamship Authority, Series A, 4.0%, 3/1/28                              4,691,981
                                                                                              --------------
                          Total Massachusetts                                                 $  242,520,327
------------------------------------------------------------------------------------------------------------
                          Michigan -- 0.7%
    2,870,000             Michigan Public Educational Facilities Authority,
                          Limited Obligation-David Ellis-West Project,
                          5.875%, 6/1/37                                                      $    3,081,433
    5,000,000             University of Michigan, 5.0%, 4/1/36                                     5,935,600
                                                                                              --------------
                          Total Michigan                                                      $    9,017,033
------------------------------------------------------------------------------------------------------------
                          Minnesota -- 2.1%
    5,000,000             City of Rochester, Health Care Facilities, Mayo Clinic,
                          4.0%, 11/15/48                                                      $    5,453,450
    3,000,000             City of Rochester, Mayo Clinic, Series B,
                          5.0%, 11/15/29                                                           3,846,750
    5,350,000             City of Rochester, Mayo Clinic, Series B,
                          5.0%, 11/15/36                                                           7,317,034
    3,000,000(d)          State of Minnesota, Series B, 3.0%, 10/1/36                              3,064,500
    2,875,000             University of Minnesota, Series A, 5.0%, 4/1/33                          3,419,784
      600,000             University of Minnesota, Series B, 4.0%, 1/1/20                            607,422
    1,000,000             University of Minnesota, Series B, 4.0%, 1/1/29                          1,096,810
      860,000             University of Minnesota, Series B, 4.0%, 1/1/30                            940,642
                                                                                              --------------
                          Total Minnesota                                                     $   25,746,392
------------------------------------------------------------------------------------------------------------
                          Mississippi -- 1.2%
    2,750,000             County of Warren, International Paper Co.,
                          Series A, 5.8%, 5/1/34                                              $    2,835,690
   11,075,000(g)          Mississippi Business Finance Corp., Chevron
                          USA, Inc., Project, Series F, 2.0%, 12/1/30                             11,075,000
                                                                                              --------------
                          Total Mississippi                                                   $   13,910,690
------------------------------------------------------------------------------------------------------------


The accompanying notes are an integral part of these financial statements.

24 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19





------------------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                                       Value
------------------------------------------------------------------------------------------------------------
                                                                                        
                          Missouri -- 0.8%
    2,500,000             Health & Educational Facilities Authority of the
                          State of Missouri, CoxHealth Hospital, Series A,
                          5.0%, 11/15/35                                                      $    2,834,800
    4,000,000             Health & Educational Facilities Authority of the
                          State of Missouri, Mercy Health, Series F,
                          4.0%, 11/15/45                                                           4,101,120
    2,000,000             Missouri Development Finance Board, City of
                          Independence-Annual Appropiation Sewer System,
                          5.25%, 11/1/42                                                           2,263,680
       75,000             Missouri State Environmental Improvement &
                          Energy Resources Authority, Unrefunded
                          Balance-St. Revolving, 5.125%, 1/1/20                                       75,196
                                                                                              --------------
                          Total Missouri                                                      $    9,274,796
------------------------------------------------------------------------------------------------------------
                          Nebraska -- 0.2%
    2,000,000             University of Nebraska, University Nebraska Lincoln
                          Student, Series A, 3.0%, 7/1/35                                     $    2,027,800
                                                                                              --------------
                          Total Nebraska                                                      $    2,027,800
------------------------------------------------------------------------------------------------------------
                          New Hampshire -- 1.0%
    4,000,000             New Hampshire Health & Education Facilities
                          Authority Act, Catholic Medical Centre,
                          3.75%, 7/1/40                                                       $    4,181,480
    7,850,000(b)          New Hampshire Health & Education Facilities
                          Authority Act, Wentworth Douglas Hospital, Series A,
                          6.5%, 1/1/41                                                             8,437,730
                                                                                              --------------
                          Total New Hampshire                                                 $   12,619,210
------------------------------------------------------------------------------------------------------------
                          New Jersey -- 1.1%
    5,000,000             New Jersey Educational Facilities Authority,
                          Princeton University, Series B, 5.0%, 7/1/27                        $    6,204,450
    3,000,000             New Jersey Educational Facilities Authority,
                          Princeton University, Series B, 5.0%, 7/1/39                             3,203,130
    2,000,000             New Jersey Transportation Trust Fund Authority,
                          Transportation System, Series A, 5.5%, 6/15/41                           2,108,760
    1,640,000(d)          Township of Plainsboro, General Improvement,
                          2.0%, 8/1/24                                                             1,687,101
                                                                                              --------------
                          Total New Jersey                                                    $   13,203,441
------------------------------------------------------------------------------------------------------------
                          New York -- 3.9%
    5,030,000             New York State Dormitory Authority, Columbia
                          University, 5.0%, 10/1/41                                           $    5,335,170
   10,000,000             New York State Dormitory Authority, Columbia
                          University, Series A-2, 5.0%, 10/1/46                                   14,512,100
    5,515,000             New York State Dormitory Authority, Insured-FIT
                          Student Housing Corp., 5.25%, 7/1/24
                          (NATL Insured)                                                           6,162,571
    4,500,000             New York State Dormitory Authority, New York
                          University, Series A, 4.0%, 7/1/36                                       4,993,065
    1,000,000             New York State Dormitory Authority, Series A,
                          4.0%, 7/1/35                                                             1,130,080


The accompanying notes are an integral part of these financial statements.

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 25



Schedule of Investments | 6/30/19 (unaudited) (continued)



------------------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                                       Value
------------------------------------------------------------------------------------------------------------
                                                                                        
                          New York -- (continued)
    5,015,000             New York State Dormitory Authority, Series A,
                          5.0%, 3/15/31                                                       $    5,893,427
    3,250,000             New York State Dormitory Authority, Trustees of
                          Columbia University, 5.0%, 10/1/45                                       4,697,940
    1,500,000             Port Authority of New York & New Jersey, Consolidated
                          Ninety-Third Series, 6.125%, 6/1/94                                      1,802,895
    2,925,000(d)          White Plains City School District, 2.0%, 5/15/28
                          (ST AID WITHHLDG Insured)                                                2,947,757
                                                                                              --------------
                          Total New York                                                      $   47,475,005
------------------------------------------------------------------------------------------------------------
                          North Carolina -- 3.0%
    3,000,000             City of Charlotte, Storm Water Revenue,
                          4.0%, 12/1/43                                                       $    3,210,450
    5,000,000             City of Fayetteville, Public Works Commission
                          Revenue, 4.0%, 3/1/44                                                    5,390,700
   10,000,000             North Carolina Turnpike Authority, Series A,
                          4.0%, 1/1/35                                                            11,350,800
    5,000,000(d)          State of North Carolina, Series A, 5.0%, 6/1/28                          6,135,200
    9,615,000(d)          State of North Carolina, St. Public Improvement
                          Connecourt, Series A, 3.0%, 6/1/35                                       9,992,966
                                                                                              --------------
                          Total North Carolina                                                $   36,080,116
------------------------------------------------------------------------------------------------------------
                          North Dakota -- 0.4%
    5,000,000             County of McLean, Great River Energy, Series B,
                          5.15%, 7/1/40                                                       $    5,159,100
                                                                                              --------------
                          Total North Dakota                                                  $    5,159,100
------------------------------------------------------------------------------------------------------------
                          Ohio -- 1.7%
   50,000,000(c)          Buckeye Tobacco Settlement Financing Authority,
                          Asset-Backed, 2nd Subordinated, Series C, 6/1/52                    $    1,495,000
   10,000,000             Buckeye Tobacco Settlement Financing Authority,
                          Asset-Backed, Series A-2, 5.75%, 6/1/34                                  9,725,000
    9,000,000             Buckeye Tobacco Settlement Financing Authority,
                          Asset-Backed, Series A-2, 6.5%, 6/1/47                                   9,045,000
      800,000             County of Lake, Lake Hospital, Series S,
                          6.0%, 8/15/43                                                              802,760
                                                                                              --------------
                          Total Ohio                                                          $   21,067,760
------------------------------------------------------------------------------------------------------------
                          Oklahoma -- 0.2%
    2,630,000             McGee Creek Authority, Oklahoma Water Revenue,
                          6.0%, 1/1/23 (NATLInsured)                                          $    2,840,216
                                                                                              --------------
                          Total Oklahoma                                                      $    2,840,216
------------------------------------------------------------------------------------------------------------
                          Oregon -- 2.2%
    1,800,000             City of Portland, Sewer System Revenue, First Lien,
                          Series A, 2.0%, 6/15/29                                             $    1,786,302
    5,000,000(d)          Clackamas County School District No. 7J Lake
                          Oswego, School District, 4.0%, 6/1/43
                          (SCH-BD GTY Insured)                                                     5,469,600


The accompanying notes are an integral part of these financial statements.

26 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19





------------------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                                       Value
------------------------------------------------------------------------------------------------------------
                                                                                        
                          Oregon -- (continued)
    3,000,000(d)          Deschutes & Jefferson Counties School District
                          No. 2J Redmond, 3.0%, 6/15/32
                          (SCH-BD GTY Insured)                                                $    3,050,100
    2,000,000(c)(d)       Multnomah County School District No. 40, Deferred
                          Interest, Series B, 6/15/30 (SCH-BD GTY Insured)                         1,534,440
    2,000,000(c)(d)       Multnomah County School District No. 40, Deferred
                          Interest, Series B, 6/15/31 (SCH-BD GTY Insured)                         1,472,700
    1,715,000(c)(d)       Multnomah County School District No. 40, Deferred
                          Interest, Series B, 6/15/32                                              1,210,618
    2,000,000             Oregon Health & Science University, Series A,
                          5.0%, 7/1/42                                                             2,352,940
    1,500,000             Oregon Health & Science University, Series B,
                          5.0%, 7/1/28                                                             1,812,390
    7,030,000(d)          State of Oregon, Series J, 5.0%, 8/1/42                                  8,348,125
                                                                                              --------------
                          Total Oregon                                                        $   27,037,215
------------------------------------------------------------------------------------------------------------
                          Pennsylvania -- 4.6%
      825,000             Chester County Industrial Development Authority,
                          Collegium Charter School, Series A,
                          5.125%, 10/15/37                                                    $      856,507
      175,000             Chester County Industrial Development Authority,
                          Collegium Charter School, Series A,
                          5.25%, 10/15/47                                                            179,818
    4,095,000             Dauphin County General Authority, Pinnacle Health
                          System Project, 5.0%, 6/1/42                                             4,386,032
    3,725,000             Delaware County Industrial Development Authority,
                          Chester Charter School Arts Project, Series A, 5.125%,
                          6/1/46 (144A)                                                            3,870,163
    1,000,000(b)          Pennsylvania Higher Educational Facilities Authority,
                          Edinboro University Foundation, 6.0%, 7/1/43                             1,045,390
    4,750,000             Pennsylvania Higher Educational Facilities Authority,
                          Thomas Jefferson University, 5.0%, 9/1/39                                5,388,922
    1,000,000             Pennsylvania Higher Educational Facilities Authority,
                          University Properties, Inc., East Stroudsburg,
                          5.0%, 7/1/42                                                             1,019,820
    1,000,000             Pennsylvania Housing Finance Agency,
                          3.35%, 10/1/45                                                             998,230
    2,000,000             Pennsylvania Housing Finance Agency,
                          3.4%, 10/1/49                                                            2,000,240
    2,000,000             Pennsylvania Turnpike Commission, Series A-1,
                          5.0%, 12/1/42                                                            2,353,160
    5,000,000             Pennsylvania Turnpike Commission, Series A-1,
                          5.0%, 12/1/47                                                            5,841,850
    2,500,000             Philadelphia Authority for Industrial Development,
                          Childrens Hospital Philadelphia, 4.0%, 7/1/35                            2,754,300
    3,750,000             Philadelphia Authority for Industrial Development,
                          Childrens Hospital Philadelphia, 4.0%, 7/1/36                            4,126,575
    2,500,000             Philadelphia Authority for Industrial Development,
                          Childrens Hospital Philadelphia, 4.0%, 7/1/37                            2,751,825


The accompanying notes are an integral part of these financial statements.

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 27



Schedule of Investments | 6/30/19 (unaudited) (continued)



------------------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                                       Value
------------------------------------------------------------------------------------------------------------
                                                                                        
                          Pennsylvania -- (continued)
    2,500,000             Philadelphia Authority for Industrial Development,
                          Childrens Hospital Philadelphia, 5.0%, 7/1/42                       $    2,841,475
    3,000,000             Philadelphia Authority for Industrial Development,
                          Thomas Jefferson University, Series A, 4.0%, 9/1/42                      3,189,150
    3,680,000             Swarthmore Borough Authority, Swarthmore College,
                          5.0%, 9/15/39                                                            4,513,446
    5,015,000             Swarthmore Borough Authority, Swarthmore College,
                          5.0%, 9/15/44                                                            6,106,114
    1,195,000             Swarthmore Borough Authority, Swarthmore College,
                          5.0%, 9/15/45                                                            1,448,065
                                                                                              --------------
                          Total Pennsylvania                                                  $   55,671,082
------------------------------------------------------------------------------------------------------------
                          Puerto Rico -- 0.3%
    7,000,000(d)(f)       Commonwealth of Puerto Rico, Series A,
                          8.0%, 7/1/35                                                        $    3,622,500
                                                                                              --------------
                          Total Puerto Rico                                                   $    3,622,500
------------------------------------------------------------------------------------------------------------
                          Rhode Island -- 1.5%
    5,140,000             Rhode Island Health & Educational Building Corp.,
                          Brown University, Series A, 4.0%, 9/1/37                            $    5,730,946
    3,750,000(g)          Tender Option Bond Trust Receipts/Certificates,
                          Series 2019-XM0721, 0.0%, 9/1/47 (144A)                                  5,124,900
   41,290,000(c)          Tobacco Settlement Financing Corp., Asset-Backed,
                          Series A, 6/1/52                                                         4,542,313
   20,000,000(c)          Tobacco Settlement Financing Corp., Asset-Backed,
                          Series B, 6/1/52                                                         2,184,600
                                                                                              --------------
                          Total Rhode Island                                                  $   17,582,759
------------------------------------------------------------------------------------------------------------
                          South Carolina -- 0.6%
    1,000,000             SCAGO Educational Facilities Corp. for Pickens
                          School District, 3.25%, 12/1/28                                     $    1,053,430
    5,675,000             South Carolina Transportation Infrastructure Bank,
                          Series A, 3.0%, 10/1/33                                                  5,774,086
      500,000(d)          State of South Carolina, St. Economic Development,
                          Series A, 5.0%, 4/1/20                                                     512,215
                                                                                              --------------
                          Total South Carolina                                                $    7,339,731
------------------------------------------------------------------------------------------------------------
                          Texas -- 9.0%
    3,550,000(c)          Central Texas Regional Mobility Authority, Capital
                          Appreciation, 1/1/26                                                $    3,079,554
    3,000,000(c)          Central Texas Regional Mobility Authority, Capital
                          Appreciation, 1/1/27                                                     2,527,320
    7,100,000(c)          Central Texas Regional Mobility Authority, Capital
                          Appreciation, Senior Lien, 1/1/25                                        6,347,613
    2,500,000(b)          Central Texas Regional Mobility Authority, Sub Lien,
                          6.75%, 1/1/41                                                            2,699,900
    5,080,000(d)          Eagle Mountain & Saginaw Independent School
                          District, 3.0%, 8/15/29 (PSF-GTD Insured)                                5,264,709
    1,000,000             Harris County Cultural Education Facilities Finance
                          Corp., YMCA Greater Houston Area, 5.0%, 6/1/28                           1,064,130


The accompanying notes are an integral part of these financial statements.

28 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19





------------------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                                       Value
------------------------------------------------------------------------------------------------------------
                                                                                        
                          Texas -- (continued)
      500,000             Harris County Cultural Education Facilities Finance
                          Corp., YMCA Greater Houston Area, 5.0%, 6/1/33                      $      527,475
    2,750,000(b)          Houston Higher Education Finance Corp., Rice
                          University Project, Series A, 5.0%, 5/15/35                              2,833,572
    8,835,000(g)          Lower Neches Valley Authority Industrial Development
                          Corp., Exxonmobil, 1.89%, 11/1/38                                        8,835,000
    5,000,000(d)          Lubbock-Cooper Independent School District,
                          4.0%, 2/15/49 (PSF-GTD Insured)                                          5,230,850
    2,000,000             New Hope Cultural Education Facilities Finance
                          Corp., Cardinal Bay, Inc., Village On The Park,
                          4.75%, 7/1/51                                                            2,170,760
    2,000,000             North Texas Tollway Authority, First Tier, Series D,
                          5.0%, 1/1/38                                                             2,126,220
    4,000,000             North Texas Tollway Authority, Second Tier, Series A,
                          5.0%, 1/1/30                                                             4,621,760
    5,000,000             North Texas Tollway Authority, Second Tier, Series A,
                          5.0%, 1/1/35                                                             5,710,850
    7,525,000(d)          State of Texas, Highway Improvement, 5.0%, 4/1/29                        8,676,927
    2,000,000             Texas Department of Housing & Community Affairs,
                          Series A, 3.5%, 7/1/34 (GNMA/FNMA Insured)                               2,099,780
    2,500,000             Texas Department of Housing & Community Affairs,
                          Series A, 3.8%, 7/1/39 (GNMA/FNMA Insured)                               2,627,850
    4,000,000             Texas Municipal Gas Acquisition & Supply Corp. III,
                          5.0%, 12/15/31                                                           4,331,520
   10,410,000             Texas Private Activity Bond Surface Transportation
                          Corp., Senior Lien-LBJ Infrastructure, 7.0%, 6/30/40                    10,926,544
    2,755,000(b)          Texas State Public Finance Authority Charter School
                          Finance Corp., Education-Cosmos Foundation, Inc.,
                          Series A, 6.2%, 2/15/40                                                  2,836,273
    5,000,000             Texas Water Development Board, St. Water
                          Implementation Fund, Series A, 4.0%, 4/15/48                             5,426,150
    5,000,000             Texas Water Development Board, State Water
                          Implementation Fund, Series B, 5.0%, 4/15/49                             6,025,400
    5,000,000             University of Texas System, Financing System,
                          Series A, 5.0%, 8/15/24                                                  5,898,100
    5,000,000             University of Texas System, Financing System,
                          Series A, 5.0%, 8/5/49                                                   7,225,500
                                                                                              --------------
                          Total Texas                                                         $  109,113,757
------------------------------------------------------------------------------------------------------------
                          Utah -- 0.6%
    1,000,000             Salt Lake City Corp. Airport Revenue, Series B,
                          5.0%, 7/1/34                                                        $    1,197,010
      110,000             Utah Charter School Finance Authority, North Davis
                          Preparatory, 5.75%, 7/15/20                                                112,224
    4,835,000             Utah Transit Authority, Series A, 5.0%, 6/15/31                          5,708,250
                                                                                              --------------
                          Total Utah                                                          $    7,017,484
------------------------------------------------------------------------------------------------------------


The accompanying notes are an integral part of these financial statements.

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 29



Schedule of Investments | 6/30/19 (unaudited) (continued)



------------------------------------------------------------------------------------------------------------
Principal
Amount
USD ($)                                                                                       Value
------------------------------------------------------------------------------------------------------------
                                                                                        
                          Virginia -- 7.4%
    1,170,000(d)          City of Manassas, 2.0%, 7/1/31 (ST AID WITHHLDG)                    $    1,109,218
    1,500,000(d)          County of Arlington, 4.0%, 8/15/35                                       1,674,420
   10,000,000(d)          County of Fairfax, Series A, 4.0%, 10/1/33
                          (ST AID WITHHLDG Insured)                                               11,225,100
    5,000,000             County of Henrico, Water & Sewer Revenue,
                          5.0%, 5/1/46                                                             5,879,800
   18,490,000             Tobacco Settlement Financing Corp., Senior,
                          Series B-1, 5.0%, 6/1/47                                                18,166,425
    4,000,000             University of Virginia, Series A, 5.0%, 6/1/37                           4,486,400
    7,075,000             University of Virginia, Series A, 5.0%, 4/1/42                           8,413,307
    5,000,000             University of Virginia, Series A, 5.0%, 6/1/43                           5,566,100
   12,000,000             University of Virginia, Series A-1, 4.0%, 4/1/45                        13,004,520
    5,000,000             Upper Occoquan Sewage Authority, 4.0%, 7/1/41                            5,361,950
   14,105,000             Virginia Public Building Authority, Series A,
                          3.0%, 8/1/38                                                            14,316,011
                                                                                              --------------
                          Total Virginia                                                      $   89,203,251
------------------------------------------------------------------------------------------------------------
                          Washington -- 6.1%
   11,000,000             Central Puget Sound Regional Transit Authority,
                          Series S-1, 5.0%, 11/1/46                                           $   15,711,850
   10,250,000             City of Seattle, Municipal Light & Power Revenue
                          Improvement, Series A, 4.0%, 1/1/48                                     11,059,238
   10,000,000             King County Housing Authority, Birch Creek Apartments
                          Project, 5.5%, 5/1/38 (CNTY GTD Insured)                                10,022,400
    3,000,000(d)          King County Issaquah School District No. 411,
                          4.5%, 12/1/30 (SCH-BD GTY Insured)                                       3,388,290
    1,500,000             Public Utility District No. 1 of Franklin County, Series A,
                          5.0%, 9/1/38                                                             1,650,300
   10,390,000(d)          State of Washington, Series 2015-D, 5.0%, 7/1/30                        12,200,042
    5,000,000(d)          State of Washington, Series 2017-A, 5.0%, 8/1/30                         6,029,600
    5,000,000(d)          State of Washington, Series A, 5.0%, 8/1/36                              5,639,300
    6,685,000             University of Washington, Series B, 5.0%, 6/1/28                         7,962,570
                                                                                              --------------
                          Total Washington                                                    $   73,663,590
------------------------------------------------------------------------------------------------------------
                          TOTAL MUNICIPAL BONDS
                          (Cost $1,115,082,631)                                               $1,186,713,975
------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------
Shares
------------------------------------------------------------------------------------------------------------
                                                                                        
                          CLAIM -- 0.0%+ of Net Assets
          200(h)          CMS Liquidating Trust                                               $     580,000
------------------------------------------------------------------------------------------------------------
                          TOTAL CLAIM
                          (Cost $640,000)                                                     $      580,000
------------------------------------------------------------------------------------------------------------
                          TOTAL INVESTMENTS IN UNAFFILIATED
                          ISSUERS -- 98.3%
                          (Cost $1,115,722,631)                                               $1,187,293,975
------------------------------------------------------------------------------------------------------------
                          OTHER ASSETS AND LIABILITIES -- 1.7%                                $   20,052,705
------------------------------------------------------------------------------------------------------------
                          NET ASSETS -- 100.0%                                                $1,207,346,680
============================================================================================================


The accompanying notes are an integral part of these financial statements.

30 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



(144A)            Security is exempt from registration under Rule 144A of the
                  Securities Act of 1933. Such securities may be resold normally
                  to qualified institutional buyers in a transaction exempt from
                  registration. At June 30, 2019, the value of these securities
                  amounted to $11,077,163, or 0.9% of net assets.

AGC               Assured Guarantee Municipal

AGM               Assured Guarantee Corp.

AMBAC             Ambac Assurance Corp.

CNTY GTD          County Guaranteed

FNMA              Federal National Mortgage Association

GNMA              Government National Mortgage Association

NATL              National Public Finance Guarantee Corp.

PSF-GTD           Permanent School Fund Guaranteed

SCH-BD GTY        School Bord Guaranty

ST AID WITHHLDG   State Aid Withholding

ST INTERCEPT      State Aid Intercept

+                 Amount rounds to less than 0.1%.

(a)               Consists of Revenue Bonds unless otherwise indicated.

(b)               Pre-refunded bonds have been collateralized by U.S. Treasury
                  or U.S. Government Agency securities, which are held in escrow
                  to pay interest and principal on the tax-exempt issue and to
                  retire the bonds in full at the earliest refunding date.

(c)               Security issued with a zero coupon. Income is recognized
                  through accretion of discount.

(d)               Represents a General Obligation Bond.

(e)               Escrow to maturity.

(f)               Security is in default.

(g)               The interest rate is subject to change periodically. The
                  interest rate and/or reference index and spread is shown at
                  June 30, 2019.

(h)               Non-income producing security.

Purchases and sales of securities (excluding temporary cash investments) for
the six months ended June 30, 2019 aggregated $125,400,594 and $39,457,978,
respectively.

The Fund is permitted to engage in purchase and sale transactions ("cross
trades") with certain funds and accounts for which Amundi Pioneer Asset
Management, Inc. (the "Adviser") serves as the Fund's investment adviser, as
set forth in Rule 17a-7 under the Investment Company Act of 1940, pursuant to
procedures adopted by the Board of Trustees. Under these procedures, cross
trades are effected at current market prices. During the six months ended June
30, 2019, the Fund did not engage in cross trade activity.

At June 30, 2019, the net unrealized appreciation on investments based on cost
for federal tax purposes of $1,115,668,724 was as follows:



                                                                                
         Aggregate gross unrealized appreciation for all investments in which
           there is an excess of value over tax cost                               $77,482,580
         Aggregate gross unrealized depreciation for all investments in which
           there is an excess of tax cost over value                                (5,857,329)
                                                                                   -----------
         Net unrealized appreciation                                               $71,625,251
                                                                                   ===========


The accompanying notes are an integral part of these financial statements.

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 31



Schedule of Investments | 6/30/19 (unaudited) (continued)

Various inputs are used in determining the value of the Fund's investments.
These inputs are summarized in the three broad levels below.

  Level 1 - quoted prices in active markets for identical securities.

  Level 2 - other significant observable inputs (including quoted prices for
            similar securities, interest rates, prepayment speeds, credit risks,
            etc.). See Notes to Financial Statements -- Note 1A.

  Level 3 - significant unobservable inputs (including the Fund's own
            assumptions in determining fair value of investments). See Notes to
            Financial Statements -- Note 1A.

The following is a summary of the inputs used as of June 30, 2019, in valuing
the Fund's investments:



---------------------------------------------------------------------------------------
                          Level 1      Level 2             Level 3      Total
---------------------------------------------------------------------------------------
                                                            
Municipal Bonds           $ --         $1,186,713,975      $ --         $1,186,713,975
Claim                       --                580,000        --                580,000
---------------------------------------------------------------------------------------
Total Investments
 in Securities            $ --         $1,187,293,975      $ --         $1,187,293,975
=======================================================================================


During the six month ended June 30, 2019, there were no transfers between
Levels 1, 2 and 3.

The accompanying notes are an integral part of these financial statements.

32 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



Statement of Assets and Liabilities | 6/30/19 (unaudited)



                                                                              
ASSETS:
  Investments in unaffiliated issuers, at value (cost $1,115,722,631)            $1,187,293,975
  Cash                                                                               13,954,719
  Receivables --
     Investment securities sold                                                       6,622,900
     Fund shares sold                                                                 3,026,589
     Interest                                                                        13,580,598
  Due from the Adviser                                                                   29,695
  Other assets                                                                           42,339
-----------------------------------------------------------------------------------------------
       Total assets                                                              $1,224,550,815
===============================================================================================
LIABILITIES:
  Payables --
     Investment securities purchased                                             $   13,288,950
     Fund shares repurchased                                                          2,048,125
     Distributions                                                                    1,474,735
     Trustees' fees                                                                       1,577
  Due to affiliates                                                                     101,139
  Accrued expenses                                                                      289,609
-----------------------------------------------------------------------------------------------
       Total liabilities                                                         $   17,204,135
===============================================================================================
NET ASSETS:
  Paid-in capital                                                                $1,134,053,100
  Distributable earnings                                                             73,293,580
-----------------------------------------------------------------------------------------------
       Net assets                                                                $1,207,346,680
===============================================================================================
NET ASSET VALUE PER SHARE:
  No par value (unlimited number of shares authorized)
     Class A (based on $603,310,190/40,587,509 shares)                           $        14.86
     Class C (based on $31,390,985/2,129,949 shares)                             $        14.74
     Class Y (based on $572,645,505/38,624,476 shares)                           $        14.83
MAXIMUM OFFERING PRICE PER SHARE:
  Class A (based on $14.86 net asset value per share/
     100%-4.50% maximum sales charge)                                            $        15.56
===============================================================================================


The accompanying notes are an integral part of these financial statements.

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 33



Statement of Operations (unaudited)

For the Six Months Ended 6/30/19



                                                                                     
INVESTMENT INCOME:
  Interest from unaffiliated issuers                                  $20,767,900
-------------------------------------------------------------------------------------------------------
     Total investment income                                                               $20,767,900
=======================================================================================================
EXPENSES:
  Management fees                                                     $ 2,532,140
  Administrative expense                                                  186,199
  Transfer agent fees
     Class A                                                              123,186
     Class C                                                                8,069
     Class Y                                                              272,001
  Distribution fees
     Class A                                                              739,381
     Class C                                                              158,009
  Shareowner communications expense                                        41,034
  Custodian fees                                                            7,240
  Registration fees                                                        37,388
  Professional fees                                                        57,426
  Printing expense                                                         11,624
  Pricing fees                                                             36,512
  Trustees' fees                                                           27,493
  Insurance expense                                                         5,080
  Miscellaneous                                                            57,180
-------------------------------------------------------------------------------------------------------
     Total expenses                                                                        $ 4,299,962
     Less fees waived and expenses reimbursed by the Adviser                                  (196,274)
-------------------------------------------------------------------------------------------------------
     Net expenses                                                                          $ 4,103,688
-------------------------------------------------------------------------------------------------------
       Net investment income                                                               $16,664,212
-------------------------------------------------------------------------------------------------------
REALIZED AND UNREALIZED GAIN (LOSS) ON INVESTMENTS:
  Net realized gain (loss) on:
     Investments in unaffiliated issuers                                                   $   443,285
-------------------------------------------------------------------------------------------------------
  Change in net unrealized appreciation (depreciation) on:
     Investments in unaffiliated issuers                                                   $49,964,409
-------------------------------------------------------------------------------------------------------
  Net realized and unrealized gain (loss) on investments                                   $50,407,694
-------------------------------------------------------------------------------------------------------
  Net increase in net assets resulting from operations                                     $67,071,906
=======================================================================================================


The accompanying notes are an integral part of these financial statements.

34 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



Statements of Changes in Net Assets



----------------------------------------------------------------------------------------------------------
                                                                    Six Months
                                                                    Ended                  Year
                                                                    6/30/19                Ended
                                                                    (unaudited)            12/31/18
----------------------------------------------------------------------------------------------------------
                                                                                     
FROM OPERATIONS:
Net investment income (loss)                                        $   16,664,212         $   34,616,395
Net realized gain (loss) on investments                                    443,285                939,313
Change in net unrealized appreciation (depreciation)
  on investments                                                        49,964,409            (36,185,345)
----------------------------------------------------------------------------------------------------------
     Net increase (decrease) in net assets resulting
       from operations                                              $   67,071,906         $     (629,637)
----------------------------------------------------------------------------------------------------------
DISTRIBUTIONS TO SHAREOWNERS:
  Class A ($0.21 and $0.41 per share, respectively)                 $   (8,452,248)        $  (17,760,328)
  Class C ($0.15 and $0.30 per share, respectively)                       (331,507)              (912,319)
  Class Y ($0.22 and $0.45 per share, respectively)                     (8,094,498)           (16,525,147)
----------------------------------------------------------------------------------------------------------
     Total distributions to shareowners                             $  (16,878,253)        $  (35,197,794)
----------------------------------------------------------------------------------------------------------
FROM FUND SHARE TRANSACTIONS:
Net proceeds from sales of shares                                   $  189,926,432         $  286,624,878
Reinvestment of distributions                                            9,141,497             19,644,431
Cost of shares repurchased                                            (115,717,520)          (531,559,261)
----------------------------------------------------------------------------------------------------------
     Net increase (decrease) in net assets resulting from
       Fund share transactions                                      $   83,350,409         $ (225,289,952)
----------------------------------------------------------------------------------------------------------
     Net increase (decrease) in net assets                          $  133,544,062         $ (261,117,383)
NET ASSETS:
Beginning of period                                                 $1,073,802,618         $1,334,920,001
----------------------------------------------------------------------------------------------------------
End of period                                                       $1,207,346,680         $1,073,802,618
==========================================================================================================


The accompanying notes are an integral part of these financial statements.

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 35



Statements of Changes in Net Assets (continued)



---------------------------------------------------------------------------------------------------------------------
                                              Six Months        Six Months
                                              Ended             Ended               Year               Year
                                              6/30/19           6/30/19             Ended              Ended
                                              Shares            Amount              12/31/18           12/31/18
                                              (unaudited)       (unaudited)         Shares             Amount
---------------------------------------------------------------------------------------------------------------------
                                                                                           
Class A
Shares sold                                    1,931,941        $ 27,928,216          2,580,767        $  36,742,481
Reinvestment of distributions                    462,760           6,756,395          1,012,132           14,405,517
Less shares repurchased                       (2,857,665)        (41,524,751)        (6,709,019)         (95,520,365)
---------------------------------------------------------------------------------------------------------------------
     Net decrease                               (462,964)       $ (6,840,140)        (3,116,120)       $ (44,372,367)
=====================================================================================================================
Class C
Shares sold                                      130,014        $  1,864,172            291,123        $   4,119,681
Reinvestment of distributions                     18,280             264,498             53,350              753,501
Less shares repurchased                         (331,731)         (4,758,231)        (1,579,787)         (22,317,473)
---------------------------------------------------------------------------------------------------------------------
     Net decrease                               (183,437)       $ (2,629,561)        (1,235,314)       $ (17,444,291)
=====================================================================================================================
Class Y
Shares sold                                   11,093,000        $160,134,044         17,279,189        $ 245,762,716
Reinvestment of distributions                    145,439           2,120,604            315,850            4,485,413
Less shares repurchased                       (4,814,893)        (69,434,538)       (29,019,039)        (413,721,423)
---------------------------------------------------------------------------------------------------------------------
     Net increase (decrease)                   6,423,546        $ 92,820,110        (11,424,000)       $(163,473,294)
=====================================================================================================================


The accompanying notes are an integral part of these financial statements.

36 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



Financial Highlights



------------------------------------------------------------------------------------------------------------------------------------
                                                           Six Months
                                                           Ended        Year        Year        Year        Year        Year
                                                           6/30/19      Ended       Ended       Ended       Ended       Ended
                                                           (unaudited)  12/31/18    12/31/17    12/31/16*   12/31/15*   12/31/14*
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                      
Class A
Net asset value, beginning of period                       $  14.23     $  14.64    $  14.12    $  14.60    $  14.49    $  13.25
------------------------------------------------------------------------------------------------------------------------------------
Increase (decrease) from investment operations:
  Net investment income (loss)                             $   0.20(a)  $   0.41(a) $   0.41(a) $   0.40(a) $   0.44(a) $   0.49
  Net realized and unrealized gain (loss) on investments       0.64        (0.41)       0.51       (0.46)       0.20        1.29
------------------------------------------------------------------------------------------------------------------------------------
Net increase (decrease) from investment operations         $   0.84     $     --    $   0.92    $  (0.06)   $   0.64    $   1.78
------------------------------------------------------------------------------------------------------------------------------------
Distributions to shareowners:
  Net investment income                                    $  (0.21)    $  (0.40)   $  (0.40)   $  (0.42)   $  (0.53)   $  (0.54)
  Net realized gain                                              --        (0.01)         --         --           --          --
------------------------------------------------------------------------------------------------------------------------------------
Total distributions                                        $  (0.21)    $  (0.41)   $  (0.40)   $  (0.42)   $  (0.53)   $  (0.54)
------------------------------------------------------------------------------------------------------------------------------------
Net increase (decrease) in net asset value                 $   0.63     $  (0.41)   $   0.52    $  (0.48)   $   0.11    $   1.24
------------------------------------------------------------------------------------------------------------------------------------
Net asset value, end of period                             $  14.86     $  14.23    $  14.64    $  14.12    $  14.60    $  14.49
====================================================================================================================================
Total return (b)                                               5.90%(c)     0.10%       6.56%      (0.50)%      4.51%      13.61%(d)
Ratio of net expenses to average net assets (e)                0.82%(f)     0.81%       0.80%       0.81%       0.82%       0.83%
Ratio of net investment income (loss) to average net
  assets                                                       2.82%(f)     2.88%       2.80%       2.73%       3.08%       3.46%
Portfolio turnover rate                                           3%(c)       16%         20%         18%         21%         29%
Net assets, end of period (in thousands)                   $603,310     $584,127    $646,525    $690,991    $709,616    $699,229
Ratios with no waiver of fees and assumption of expenses
  by the Adviser and no reduction for fees paid
  indirectly:
  Total expenses to average net assets                         0.82%(f)     0.81%       0.80%       0.81%       0.83%       0.85%
  Net investment income (loss) to average net assets           2.82%(f)     2.88%       2.80%       2.73%       3.07%       3.44%
====================================================================================================================================


*     The Fund was audited by an independent registered public accounting firm
      other than Ernst & Young LLP.

(a)   The per-share data presented above is based on the average shares
      outstanding for the period presented.

(b)   Assumes initial investment at net asset value at the beginning of each
      period, reinvestment of all distributions, the complete redemption of the
      investment at net asset value at the end of each period and no sales
      charges. Total return would be reduced if sales charges were taken into
      account.

(c)   Not annualized.

(d)   If the Fund had not recognized gains in the settlement of class action
      lawsuits during the year ended December 31, 2014, the total return would
      have been 13.53%.

(e)   Includes interest expense of 0.00%, 0.00%, 0.00%, 0.00%, 0.00% and 0.01%,
      respectively.

(f)   Annualized.

The accompanying notes are an integral part of these financial statements.

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 37



Financial Highlights (continued)



------------------------------------------------------------------------------------------------------------------------------------
                                                                 Six Months
                                                                 Ended       Year       Year       Year       Year       Year
                                                                 6/30/19     Ended      Ended      Ended      Ended      Ended
                                                                 (unaudited) 12/31/18   12/31/17   12/31/16*  12/31/15*  12/31/14*
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                       
Class C
Net asset value, beginning of period                             $ 14.11     $ 14.51    $ 14.00    $ 14.48    $ 14.37    $ 13.14
------------------------------------------------------------------------------------------------------------------------------------
Increase (decrease) from investment operations:
  Net investment income (loss)                                   $  0.15(a)  $  0.30(a) $  0.29(a) $  0.29(a) $  0.33(a) $  0.36
  Net realized and unrealized gain (loss) on investments            0.63       (0.40)      0.51      (0.46)      0.20       1.30
------------------------------------------------------------------------------------------------------------------------------------
Net increase (decrease) from investment operations               $  0.78     $ (0.10)   $  0.80    $ (0.17)   $  0.53    $  1.66
------------------------------------------------------------------------------------------------------------------------------------
Distributions to shareowners:
  Net investment income                                          $ (0.15)    $ (0.29)   $ (0.29)   $ (0.31)   $ (0.42)   $ (0.43)
  Net realized gain                                                   --       (0.01)        --         --         --         --
------------------------------------------------------------------------------------------------------------------------------------
Total distributions                                              $ (0.15)    $ (0.30)   $ (0.29)   $ (0.31)   $ (0.42)   $ (0.43)
------------------------------------------------------------------------------------------------------------------------------------
Net increase (decrease) in net asset value                       $  0.63     $ (0.40)   $  0.51    $ (0.48)   $  0.11    $  1.23
------------------------------------------------------------------------------------------------------------------------------------
Net asset value, end of period                                   $ 14.74     $ 14.11    $ 14.51    $ 14.00    $ 14.48    $ 14.37
====================================================================================================================================
Total return (b)                                                    5.54%(c)   (0.60)%     5.72%     (1.27)%     3.74%     12.75%(d)
Ratio of net expenses to average net assets (e)                     1.57%(f)    1.57%      1.55%      1.56%      1.56%      1.60%
Ratio of net investment income (loss) to average net assets         2.06%(f)    2.13%      2.05%      1.98%      2.33%      2.69%
Portfolio turnover rate                                                3%(c)      16%        20%        18%        21%        29%
Net assets, end of period (in thousands)                         $31,391     $32,636    $51,506    $61,832    $54,752    $47,734
====================================================================================================================================


*     The Fund was audited by an independent registered public accounting firm
      other than Ernst & Young LLP.

(a)   The per-share data presented above is based on the average shares
      outstanding for the period presented.

(b)   Assumes initial investment at net asset value at the beginning of each
      period, reinvestment of all distributions, the complete redemption of the
      investment at net asset value at the end of each period and no sales
      charges. Total return would be reduced if sales charges were taken into
      account.

(c)   Not annualized.

(d)   If the Fund had not recognized gains in the settlement of class action
      lawsuits during the year ended December 31, 2014, the total return would
      have been 12.67%.

(e)   Includes interest expense of 0.00%, 0.00%, 0.00%, 0.00%, 0.00% and 0.01%,
      respectively.

(f)   Annualized.

The accompanying notes are an integral part of these financial statements.

38 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19





------------------------------------------------------------------------------------------------------------------------------------
                                                            Six Months
                                                            Ended        Year        Year        Year        Year        Year
                                                            6/30/19      Ended       Ended       Ended       Ended       Ended
                                                            (unaudited)  12/31/18    12/31/17    12/31/16*   12/31/15*   12/31/14*
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                       
Class Y
Net asset value, beginning of period                        $  14.19     $  14.60    $  14.08    $  14.56    $  14.44    $ 13.21
------------------------------------------------------------------------------------------------------------------------------------
Increase (decrease) from investment operations:
  Net investment income (loss)                              $   0.22(a)  $   0.45(a) $   0.44(a) $   0.44(a) $   0.48(a) $  0.46
  Net realized and unrealized gain (loss) on investments        0.64        (0.41)       0.51       (0.46)       0.21       1.35
------------------------------------------------------------------------------------------------------------------------------------
Net increase (decrease) from investment operations          $   0.86     $   0.04    $   0.95    $  (0.02)   $   0.69    $  1.81
------------------------------------------------------------------------------------------------------------------------------------
Distributions to shareowners:
  Net investment income                                     $  (0.22)    $  (0.44)   $  (0.43)   $  (0.46)   $  (0.57)   $ (0.58)
  Net realized gain                                               --        (0.01)         --          --          --         --
------------------------------------------------------------------------------------------------------------------------------------
Total distributions                                         $  (0.22)    $  (0.45)   $  (0.43)   $  (0.46)   $  (0.57)   $ (0.58)
------------------------------------------------------------------------------------------------------------------------------------
Net increase (decrease) in net asset value                  $   0.64     $  (0.41)   $   0.52    $  (0.48)   $   0.12    $  1.23
------------------------------------------------------------------------------------------------------------------------------------
Net asset value, end of period                              $  14.83     $  14.19    $  14.60    $  14.08    $  14.56    $ 14.44
====================================================================================================================================
Total return (b)                                                6.12%(c)     0.35%       6.84%      (0.25)%      4.86%     13.86%(d)
Ratio of net expenses to average net assets (e)                 0.55%(f)     0.55%       0.55%       0.55%       0.55%      0.56%
Ratio of net investment income (loss) to average net assets     3.08%(f)     3.13%       3.04%       2.98%       3.34%      3.70%
Portfolio turnover rate                                            3%(c)       16%         20%         18%         21%        29%
Net assets, end of period (in thousands)                    $572,646     $457,039    $636,889    $374,674    $276,778    $97,387
Ratios with no waiver of fees and assumption of expenses by
  the Adviser and no reduction for fees paid indirectly:
  Total expenses to average net assets                          0.63%(f)     0.65%       0.63%       0.64%       0.64%      0.65%
  Net investment income (loss) to average net assets            3.00%(f)     3.03%       2.96%       2.89%       3.25%      3.61%
====================================================================================================================================


*     The Fund was audited by an independent registered public accounting firm
      other than Ernst & Young LLP.

(a)   The per-share data presented above is based on the average shares
      outstanding for the period presented.

(b)   Assumes initial investment at net asset value at the beginning of each
      period, reinvestment of all distributions and the complete redemption of
      the investment at net asset value at the end of each period.

(c)   Not annualized.

(d)   If the Fund had not recognized gains in the settlement of class action
      lawsuits during the year ended December 31, 2014, the total return would
      have been 13.78%.

(e)   Includes interest expense of 0.00%, 0.00%, 0.00%, 0.00%, 0.00% and 0.01%,
      respectively.

(f)   Annualized.

The accompanying notes are an integral part of these financial statements.

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 39



Notes to Financial Statements | 6/30/19 (unaudited)

1. Organization and Significant Accounting Policies

Pioneer AMT-Free Municipal Fund (the "Fund") is one of two series comprising
Pioneer Series Trust II (the "Trust"), a Delaware statutory trust. The Fund is
registered under the Investment Company Act of 1940 as a diversified, open-end
management investment company. The investment objective of the Fund is to seek a
high level of current income exempt from federal income tax as is consistent
with the relative stability of capital.

The Fund offers three classes of shares designated as Class A, Class C and Class
Y shares. Class K shares had not commenced operations as of June 30, 2019. Each
class of shares represents an interest in the same portfolio of investments of
the Fund and has identical rights (based on relative net asset values) to assets
and liquidation proceeds. Share classes can bear different rates of
class-specific fees and expenses, such as transfer agent and distribution fees.
Differences in class-specific fees and expenses will result in differences in
net investment income and, therefore, the payment of different dividends from
net investment income earned by each class. The Amended and Restated Declaration
of Trust of the Fund gives the Board of Trustees the flexibility to specify
either per-share voting or dollar-weighted voting when submitting matters for
shareowner approval. Under per-share voting, each share of a class of the Fund
is entitled to one vote. Under dollar-weighted voting, a shareowner's voting
power is determined not by the number of shares owned, but by the dollar value
of the shares on the record date. Each share class has exclusive voting rights
with respect to matters affecting only that class, including with respect to the
distribution plan for that class. There is no distribution plan for Class Y
shares.

Amundi Pioneer Asset Management, Inc., an indirect, wholly owned subsidiary of
Amundi and Amundi's wholly owned subsidiary, Amundi USA, Inc., serves as the
Fund's investment adviser (the "Adviser"). Amundi Pioneer Distributor, Inc., an
affiliate of Amundi Pioneer Asset Management, Inc., serves as the Fund's
distributor (the "Distributor").

In August 2018, the Securities and Exchange Commission ("SEC") released a
Disclosure Update and Simplification Final Rule. The Final Rule amends
Regulation S-X disclosures requirements to conform them to U.S. Generally
Accepted Accounting Principles ("U.S. GAAP") for investment companies. The
Fund's financial statements were prepared in compliance with the new amendments
to Regulation S-X.

The Fund is an investment company and follows investment company accounting and
reporting guidance under U.S. GAAP. U.S. GAAP requires the management of the
Fund to make estimates and assumptions that affect the

40 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



reported amounts of assets and liabilities, the disclosure of contingent assets
and liabilities at the date of the financial statements, and the reported
amounts of income, expenses and gain or loss on investments during the reporting
period. Actual results could differ from those estimates.

The following is a summary of significant accounting policies followed by the
Fund in the preparation of its financial statements:

A.    Security Valuation

      The net asset value of the Fund is computed once daily, on each day the
      New York Stock Exchange ("NYSE") is open, as of the close of regular
      trading on the NYSE.

      Fixed-income securities are valued by using prices supplied by independent
      pricing services, which consider such factors as market prices, market
      events, quotations from one or more brokers, Treasury spreads, yields,
      maturities and ratings, or may use a pricing matrix or other fair value
      methods or techniques to provide an estimated value of the security or
      instrument. A pricing matrix is a means of valuing a debt security on the
      basis of current market prices for other debt securities, historical
      trading patterns in the market for fixed-income securities and/or other
      factors. Non-U.S. debt securities that are listed on an exchange will be
      valued at the bid price obtained from an independent third party pricing
      service. When independent third party pricing services are unable to
      supply prices, or when prices or market quotations are considered to be
      unreliable, the value of that security may be determined using quotations
      from one or more broker-dealers.

      Shares of open-end registered investment companies (including money market
      mutual funds) are valued at such funds' net asset value. Shares of
      exchange-listed closed-end funds are valued by using the last sale price
      on the principal exchange where they are traded.

      Securities for which independent pricing services or broker-dealers are
      unable to supply prices or for which market prices and/or quotations are
      not readily available or are considered to be unreliable are valued by a
      fair valuation team comprised of certain personnel of the Adviser pursuant
      to procedures adopted by the Fund's Board of Trustees. The Adviser's fair
      valuation team uses fair value methods approved by the Valuation Committee
      of the Board of Trustees. The Adviser's fair valuation team is responsible
      for monitoring developments that may impact fair valued securities and for
      discussing and assessing fair values on an ongoing basis, and at least
      quarterly, with the Valuation Committee of the Board of Trustees.

      Inputs used when applying fair value methods to value a security may
      include credit ratings, the financial condition of the company, current
      market conditions and comparable securities. The Fund may use fair value
      methods

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 41



      if it is determined that a significant event has occurred after the close
      of the exchange or market on which the security trades and prior to the
      determination of the Fund's net asset value. Examples of a significant
      event might include political or economic news, corporate restructurings,
      natural disasters, terrorist activity or trading halts. Thus, the
      valuation of the Fund's securities may differ significantly from exchange
      prices, and such differences could be material.

      At June 30, 2019, no securities were valued using fair value methods
      (other than securities valued using prices supplied by independent pricing
      services, broker-dealers or using a third party insurance industry pricing
      model).

B.    Investment Income and Transactions

      Interest income, including interest on income-bearing cash accounts, is
      recorded on the accrual basis. Dividend and interest income are reported
      net of unrecoverable foreign taxes withheld at the applicable country
      rates and net of income accrued on defaulted securities.

      Interest and dividend income payable by delivery of additional shares is
      reclassified as PIK (payment-in-kind) income upon receipt and is included
      in interest and dividend income, respectively.

      Security transactions are recorded as of trade date. Gains and losses on
      sales of investments are calculated on the identified cost method for both
      financial reporting and federal income tax purposes.

C.    Federal Income Taxes

      It is the Fund's policy to comply with the requirements of the Internal
      Revenue Code applicable to regulated investment companies and to
      distribute all of its net taxable income and net realized capital gains,
      if any, to its shareowners. Therefore, no provision for federal income
      taxes is required. As of December 31, 2018, the Fund did not accrue any
      interest or penalties with respect to uncertain tax positions, which, if
      applicable, would be recorded as an income tax expense on the Statement of
      Operations. Tax returns filed within the prior three years remain subject
      to examination by federal and state tax authorities.

      The amount and character of income and capital gain distributions to
      shareowners are determined in accordance with federal income tax rules,
      which may differ from U.S. GAAP. Distributions in excess of net investment
      income or net realized gains are temporary over distributions for
      financial statement purposes resulting from differences in the recognition
      or classification of income or distributions for financial statement and
      tax purposes. Capital accounts within the financial statements are
      adjusted for permanent book/tax differences to reflect tax character, but
      are not adjusted for temporary differences.

42 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



      The tax character of current year distributions payable will be determined
      at the end of the current taxable year. The tax character of distributions
      paid during the year ended December 31, 2018 was as follows:



      --------------------------------------------------------------------------
                                                                           2018
      --------------------------------------------------------------------------
                                                                 
      Distributions paid from:
      Ordinary income                                               $ 1,319,418
      Tax-exempt income                                              32,702,074
      Long-term capital gain                                          1,176,302
      --------------------------------------------------------------------------
          Total                                                     $35,197,794
      ==========================================================================


      The following shows the components of distributable earnings on a federal
      income tax basis at December 31, 2018:



      --------------------------------------------------------------------------
                                                                           2018
      --------------------------------------------------------------------------
                                                                 
      Distributable earnings:
      Undistributed tax exempt income                               $ 3,709,026
      Current year late year loss                                    (2,269,941)
      Net unrealized appreciation                                    21,660,842
      --------------------------------------------------------------------------
          Total                                                     $23,099,927
      ==========================================================================


      The difference between book-basis and tax-basis unrealized appreciation is
      attributable to the tax deferral of losses on wash sales, tax treatment of
      premium and amortization, and tax adjustments on defaulted bonds.

D.    Fund Shares

      The Fund records sales and repurchases of its shares as of trade date. The
      Distributor earned $9,620 in underwriting commissions on the sale of Class
      A shares during the six months ended June 30, 2019.

E.    Class Allocations

      Income, common expenses and realized and unrealized gains and losses are
      calculated at the Fund level and allocated daily to each class of shares
      based on its respective percentage of adjusted net assets at the beginning
      of the day.

      Distribution fees are calculated based on the average daily net asset
      value attributable to Class A and Class C shares of the Fund, respectively
      (see Note 4). Class Y shares do not pay distribution fees. All expenses
      and fees paid to the Fund's transfer agent for its services are allocated
      among the classes of shares based on the number of accounts in each class
      and the ratable allocation of related out-of-pocket expenses (see Note 3).

      The Fund declares as daily dividends substantially all of its net
      investment income. All dividends are paid on a monthly basis. Short-term
      capital gain distributions, if any, may be declared with the daily
      dividends. Distributions to shareowners are recorded as of the ex-dividend
      date. Distributions paid by

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 43



      the Fund with respect to each class of shares are calculated in the same
      manner and at the same time, except that net investment income dividends
      to Class A, Class C and Class Y shares can reflect different transfer
      agent and distribution expense rates.

F.    Risks

      The value of securities held by the Fund may go up or down, sometimes
      rapidly or unpredictably, due to general market conditions, such as real
      or perceived adverse economic, political or regulatory conditions,
      inflation, changes in interest rates, lack of liquidity in the bond
      markets or adverse investor sentiment. In the past several years,
      financial markets have experienced increased volatility, depressed
      valuations, decreased liquidity and heightened uncertainty. These
      conditions may continue, recur, worsen or spread. A general rise in
      interest rates could adversely affect the price and liquidity of
      fixed-income securities and could also result in increased redemptions
      from the Fund.

      At times, the Fund's investments may represent industries or industry
      sectors that are interrelated or have common risks, making the Fund more
      susceptible to any economic, political, or regulatory developments or
      other risks affecting those industries and sectors. The Fund's investments
      in foreign markets and countries with limited developing markets may
      subject the Fund to a greater degree of risk than investments in a
      developed market. These risks include disruptive political or economic
      conditions and the imposition of adverse governmental laws or currency
      exchange restrictions.

      The municipal bond market can be susceptible to unusual volatility,
      particularly for lower-rated and unrated securities. Liquidity can be
      reduced unpredictably in response to overall economic conditions or credit
      tightening. Municipal issuers may be adversely affected by rising health
      care costs, increasing unfunded pension liabilities, and by the phasing
      out of federal programs providing financial support. Unfavorable
      conditions and developments relating to projects financed with municipal
      securities can result in lower revenues to issuers of municipal
      securities, potentially resulting in defaults. Issuers often depend on
      revenues from these projects to make principal and interest payments. The
      value of municipal securities can also be adversely affected by changes in
      the financial condition of one or more individual municipal issuers or
      insurers of municipal issuers, regulatory and political developments, tax
      law changes or other legislative actions, and by uncertainties and public
      perceptions concerning these and other factors. Municipal securities may
      be more susceptible to downgrades or defaults during recessions or similar
      periods of economic stress. In recent periods, an increasing number of
      municipal issuers in the United States have defaulted on obligations and
      commenced insolvency proceedings. Financial difficulties

44 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



      of municipal issuers may continue or get worse. To the extent the Fund
      invests significantly in a single state, including California, Florida,
      Massachusetts, Texas, Virginia and Washington, or in securities the
      payments on which are dependent upon a single project or source of
      revenues, or that relate to a sector or industry, including health care
      facilities, education, transportation, special revenues and pollution
      control, the Fund will be more susceptible to associated risks and
      developments.

      With the increased use of technologies such as the Internet to conduct
      business, the Fund is susceptible to operational, information security and
      related risks. While the Fund's Adviser has established business
      continuity plans in the event of, and risk management systems to prevent,
      limit or mitigate, such cyber-attacks, there are inherent limitations in
      such plans and systems, including the possibility that certain risks have
      not been identified. Furthermore, the Fund cannot control the
      cybersecurity plans and systems put in place by service providers to the
      Fund such as Brown Brothers Harriman & Co., the Fund's custodian and
      accounting agent, and DST Asset Manager Solutions, Inc., the Fund's
      transfer agent. In addition, many beneficial owners of Fund shares hold
      them through accounts at broker-dealers, retirement platforms and other
      financial market participants over which neither the Fund nor Amundi
      Pioneer exercises control. Each of these may in turn rely on service
      providers to them, which are also subject to the risk of cyber-attacks.
      Cybersecurity failures or breaches at Amundi Pioneer or the Fund's service
      providers or intermediaries have the ability to cause disruptions and
      impact business operations, potentially resulting in financial losses,
      interference with the Fund's ability to calculate its net asset value,
      impediments to trading, the inability of Fund shareowners to effect share
      purchases, redemptions or exchanges or receive distributions, loss of or
      unauthorized access to private shareowner information and violations of
      applicable privacy and other laws, regulatory fines, penalties,
      reputational damage, or additional compliance costs. Such costs and losses
      may not be covered under any insurance. In addition, maintaining vigilance
      against cyber-attacks may involve substantial costs over time, and system
      enhancements may themselves be subject to cyber-attacks.

      The Fund's prospectus contains unaudited information regarding the Fund's
      principal risks. Please refer to that document when considering the Fund's
      principal risks.

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 45



2. Management Agreement

The Adviser manages the Fund's portfolio. Effective October 1, 2018, management
fees are calculated daily at the annual rate of 0.50% of the Fund's average
daily net assets up to $250 million, 0.45% of the next $500 million of the
Fund's average daily net assets, 0.40% of the next $1.25 billion of the Fund's
average daily net assets, and 0.35% of the Fund's average daily net assets over
$2 billion. Prior to October 1, 2018, management fees were calculated daily at
the annual rate of 0.50% of the Fund's average daily net assets up to $250
million, 0.45% of the next $500 million of the Fund's average daily net assets,
and 0.40% of the Fund's average daily net assets over $750 million. For the six
months ended June 30, 2019, the effective management fee (excluding waivers
and/or assumptions of expenses) was equivalent to 0.44% (annualized) of the
Fund's average daily net assets.

The Adviser has contractually agreed to limit ordinary operating expenses
(ordinary operating expenses means all fund expenses other than extraordinary
expenses, such as litigation, taxes, brokerage commissions and acquired fund
fees and expenses) of the Fund to the extent required to reduce Fund expenses to
0.55% of the average daily net assets attributable to Class Y shares. This
expense limitation is in effect through May 1, 2020. Prior to May 1, 2019, the
Adviser contractually agreed to limit ordinary opening expenses to the extent
required to reduce Fund expenses to 0.82% of the average daily net assets
attributable to Class A shares. Fees waived and expenses reimbursed during the
six months ended June 30, 2019, are reflected on the Statement of Operations.
There can be no assurance that the Adviser will extend the expense limitation
agreement for a class of shares beyond the date referred to above.

In addition, under the management and administration agreements, certain other
services and costs, including accounting, regulatory reporting and insurance
premiums, are paid by the Fund as administrative reimbursements. Included in
"Due to affiliates" reflected on the Statement of Assets and Liabilities is
$76,152 in management fees, administrative costs and certain other
reimbursements payable to the Adviser at June 30, 2019.

3. Transfer Agent

DST Asset Manager Solutions, Inc. serves as the transfer agent to the Fund at
negotiated rates. Transfer agent fees and payables shown on the Statement of
Operations and the Statement of Assets and Liabilities, respectively, include
sub-transfer agent expenses incurred through the Fund's omnibus relationship
contracts.

46 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



In addition, the Fund reimbursed the transfer agent for out-of-pocket expenses
incurred by the transfer agent related to shareowner communications activities
such as proxy and statement mailings, and outgoing phone calls. For the six
months ended June 30, 2019, such out-of-pocket expenses by class of shares were
as follows:



--------------------------------------------------------------------------------
Shareowner Communications:
--------------------------------------------------------------------------------
                                                                     
Class A                                                                 $31,170
Class C                                                                     831
Class Y                                                                   9,033
--------------------------------------------------------------------------------
 Total                                                                  $41,034
================================================================================


4. Distribution Plan and Service Plans

The Fund has adopted a distribution plan (the "Plan") pursuant to Rule 12b-1 of
the Investment Company Act of 1940 with respect to its Class A and Class C
shares. Pursuant to the Plan, the Fund pays the Distributor 0.25% of the
average daily net assets attributable to Class A shares as compensation for
personal services and/or account maintenance services or distribution services
with regard to Class A shares. Pursuant to the Plan, the Fund also pays the
Distributor 1.00% of the average daily net assets attributable to Class C
shares. The fee for Class C shares consists of a 0.25% service fee and a 0.75%
distribution fee paid as compensation for personal services and/or account
maintenance services or distribution services with regard to Class C shares.
Included in "Due to affiliates" reflected on the Statement of Assets and
Liabilities is $24,987 in distribution fees payable to the Distributor, at June
30, 2019.

In addition, redemptions of Class A and Class C shares may be subject to a
contingent deferred sales charge ("CDSC"). A CDSC of 1.00% may be imposed on
redemptions of certain net asset value purchases of Class A shares within
12 months of purchase. Redemptions of Class C shares within 12 months of
purchase are subject to a CDSC of 1.00%, based on the lower of cost or market
value of shares being redeemed. Shares purchased as part of an exchange remain
subject to any CDSC that applied to the original purchase of those shares.
There is no CDSC for Class Y shares. Proceeds from the CDSCs are paid to the
Distributor. For the six months ended June 30, 2019, CDSCs in the amount of $6
were paid to the Distributor.

5. Line of Credit Facility

The Fund, along with certain other funds in the Pioneer Family of Funds (the
"Funds"), participates in a committed, unsecured revolving line of credit
facility. Borrowings are used solely for temporary or emergency purposes. The
Fund may borrow up to the lesser of the amount available under the facility or

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 47



the limits set for borrowing by the Fund's prospectus and the 1940 Act.
Effective August 1, 2018, the Fund participates in a credit facility that is in
the amount of $250 million. Under such credit facility, depending on the type
of loan, interest on borrowings is payable at the London Interbank Offered Rate
("LIBOR") plus 0.90% on an annualized basis, or the Alternate Base Rate, which
is the greater of (a) the facility's administrative agent's daily announced
prime rate on the borrowing date, (b) 2% plus the Federal Funds Rate on the
borrowing date, or (c) 2% plus the overnight Eurodollar rate on the borrowing
date. The Funds pay an annual commitment fee to participate in a credit
facility. The commitment fee is allocated among participating Funds based on an
allocation schedule set forth in the credit agreement. For the six months ended
June 30, 2019, the Fund had no borrowings under the credit facility.

48 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



Trustees, Officers and Service Providers

Trustees                         Officers
Thomas J. Perna, Chairman        Lisa M. Jones, President and
David R. Bock                      Chief Executive Officer
Diane Durnin                     Mark E. Bradley, Treasurer and
Benjamin M. Friedman               Chief Financial and
Margaret B.W. Graham               Accounting Officer
Lisa M. Jones                    Christopher J. Kelley, Secretary and
Lorraine H. Monchak                Chief Legal Officer
Marguerite A. Piret
Fred J. Ricciardi
Kenneth J. Taubes

Investment Adviser and Administrator
Amundi Pioneer Asset Management, Inc.

Custodian and Sub-Administrator
Brown Brothers Harriman & Co.

Principal Underwriter
Amundi Pioneer Distributor, Inc.

Legal Counsel
Morgan, Lewis & Bockius LLP

Transfer Agent
DST Asset Manager Solutions, Inc.

Proxy Voting Policies and Procedures of the Fund are available without charge,
upon request, by calling our toll free number (1-800-225-6292). Information
regarding how the Fund voted proxies relating to portfolio securities during
the most recent 12-month period ended June 30 is publicly available to
shareowners at www.amundipioneer.com/us. This information is also available on
the Securities and Exchange Commission's web site at www.sec.gov.

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 49



                          This page is for your notes.

50 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



                          This page is for your notes.

                Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19 51



                          This page is for your notes.

52 Pioneer AMT-Free Municipal Fund | Semiannual Report | 6/30/19



How to Contact Amundi Pioneer

We are pleased to offer a variety of convenient ways for you to contact us for
assistance or information.

Call us for:
--------------------------------------------------------------------------------
Account Information, including existing accounts,
new accounts, prospectuses, applications
and service forms                                                 1-800-225-6292

FactFoneSM for automated fund yields, prices,
account information and transactions                              1-800-225-4321

Retirement plans information                                      1-800-622-0176

Write to us:
--------------------------------------------------------------------------------
Amundi Pioneer
P.O. Box 219427
Kansas City, MO 64121-9427

Our toll-free fax                                                 1-800-225-4240

Our internet e-mail address                us.askamundipioneer@amundipioneer.com
(for general questions about Amundi Pioneer only)

Visit our web site: www.amundipioneer.com/us

This report must be preceded or accompanied by a prospectus.

The Fund files a complete schedule of portfolio holdings with the Securities
and Exchange Commission for the first and third quarters of each fiscal year as
an exhibit to its reports on Form N-PORT. Shareholders may view the filed Form
N-PORT by visiting the Commission's web site at https://www.sec.gov.



[LOGO]   Amundi Pioneer
         ==============
       ASSET MANAGEMENT

Amundi Pioneer Asset Management, Inc.
60 State Street
Boston, MA 02109
www.amundipioneer.com/us

Securities offered through Amundi Pioneer Distributor, Inc.
60 State Street, Boston, MA 02109
Underwriter of Pioneer Mutual Funds, Member SIPC
[C] 2019 Amundi Pioneer Asset Management 19451-13-0819





ITEM 2. CODE OF ETHICS.

(a) Disclose whether, as of the end of the period covered by the report, the
registrant has adopted a code of ethics that applies to the registrant's
principal executive officer, principal financial officer, principal accounting
officer or controller, or persons performing similar functions, regardless of
whether these individuals are employed by the registrant or a third party.  If
the registrant has not adopted such a code of ethics, explain why it has not
done so.

The registrant has adopted, as of the end of the period covered by this report,
a code of ethics that applies to the registrant's principal executive officer,
principal financial officer, principal accounting officer and controller.

(b) For purposes of this Item, the term "code of ethics" means written standards
that are reasonably designed to deter wrongdoing and to promote:

        (1) Honest and ethical conduct, including the ethical handling of actual
        or apparent conflicts of interest between personal and professional
        relationships;

        (2) Full, fair, accurate, timely, and understandable disclosure in
        reports and documents that a registrant files with, or submits to, the
        Commission and in other public communications made by the registrant;

        (3) Compliance with applicable governmental laws, rules, and
        regulations;

        (4) The prompt internal reporting of violations of the code to an
        appropriate person or persons identified in the code; and

        (5) Accountability for adherence to the code.

(c) The registrant must briefly describe the nature of any amendment, during the
period covered by the report, to a provision of its code of ethics that applies
to the registrant's principal executive officer, principal financial officer,
principal accounting officer or controller, or persons performing similar
functions, regardless of whether these individuals are employed by the
registrant or a third party, and that relates to any element of the code of
ethics definition enumerated in paragraph (b) of this Item. The registrant must
file a copy of any such amendment as an exhibit pursuant to Item 10(a), unless
the registrant has elected to satisfy paragraph (f) of this Item by posting its
code of ethics on its website pursuant to paragraph (f)(2) of this Item, or by
undertaking to provide its code of ethics to any person without charge, upon
request, pursuant to paragraph (f)(3) of this Item.

The registrant has made no amendments to the code of ethics during the period
covered by this report.

(d) If the registrant has, during the period covered by the report, granted a
waiver, including an implicit waiver, from a provision of the code of ethics to
the registrant's principal executive officer, principal financial officer,
principal accounting officer or controller, or persons performing similar
functions, regardless of whether these individuals are employed by the
registrant or a third party, that relates to one or more of the items set forth
in paragraph (b) of this Item, the registrant must briefly describe the nature
of the waiver, the name of the person to whom the waiver was granted, and the
date of the waiver.

Not applicable.

(e) If the registrant intends to satisfy the disclosure requirement under
paragraph (c) or (d) of this Item regarding an amendment to, or a waiver from,
a provision of its code of ethics that applies to the registrant's principal
executive officer, principal financial officer, principal accounting officer or
controller, or persons performing similar functions and that relates to any
element of the code of ethics definition enumerated in paragraph (b) of this
Item by posting such information on its Internet website, disclose the
registrant's Internet address and such intention.

Not applicable.

(f) The registrant must:

        (1) File with the Commission, pursuant to Item 12(a)(1), a copy of
        its code of ethics that applies to the registrant's principal
        executive officer,principal financial officer, principal accounting
        officer or controller, or persons performing similar functions,
        as an exhibit to its annual
        report on this Form N-CSR (see attachment);

        (2) Post the text of such code of ethics on its Internet website and
        disclose, in its most recent report on this Form N-CSR, its Internet
        address and the fact that it has posted such code of ethics on its
        Internet website; or

        (3) Undertake in its most recent report on this Form N-CSR to provide to
        any person without charge, upon request, a copy of such code of ethics
        and explain the manner in which such request may be made.
	See Item 10(2)

ITEM 3. AUDIT COMMITTEE FINANCIAL EXPERT.

(a) (1)  Disclose that the registrant's board of trustees has determined that
         the registrant either:

    (i)  Has at least one audit committee financial expert serving on its audit
         committee; or

    (ii) Does not have an audit committee financial expert serving on its audit
         committee.

The registrant's Board of Trustees has determined that the registrant has at
least one audit committee financial expert.

    (2) If the registrant provides the disclosure required by paragraph
(a)(1)(i) of this Item, it must disclose the name of the audit committee
financial expert and whether that person is "independent." In order to be
considered "independent" for purposes of this Item, a member of an audit
committee may not, other than in his or her capacity as a member of the audit
committee, the board of trustees, or any other board committee:

    (i)  Accept directly or indirectly any consulting, advisory, or other
         compensatory fee from the issuer; or

    (ii) Be an "interested person" of the investment company as defined in
         Section 2(a)(19) of the Act (15 U.S.C. 80a-2(a)(19)).

Mr. David R. Bock, an independent trustee, is such an audit committee
financial expert.

    (3) If the registrant provides the disclosure required by paragraph (a)(1)
(ii) of this Item, it must explain why it does not have an audit committee
financial expert.

Not applicable.


ITEM 4. PRINCIPAL ACCOUNTANT FEES AND SERVICES.

(a) Disclose, under the caption AUDIT FEES, the aggregate fees billed for each
of the last two fiscal years for professional services rendered by the principal
accountant for the audit of the registrant's annual financial statements or
services that are normally provided by the accountant in connection with
statutory and regulatory filings or engagements for those fiscal years.

N/A

(b) Disclose, under the caption AUDIT-RELATED FEES, the aggregate fees billed in
each of the last two fiscal years for assurance and related services by the
principal accountant that are reasonably related to the performance of the audit
of the registrant's financial statements and are not reported under
paragraph (a) of this Item. Registrants shall describe the nature of the
services comprising the fees disclosed under this category.

N/A


(c) Disclose, under the caption TAX FEES, the aggregate fees billed in each of
the last two fiscal years for professional services rendered by the principal
accountant for tax compliance, tax advice, and tax planning. Registrants shall
describe the nature of the services comprising the fees disclosed under this
category.

N/A

(d) Disclose, under the caption ALL OTHER FEES, the aggregate fees billed in
each of the last two fiscal years for products and services provided by the
principal accountant, other than the services reported in paragraphs (a) through
(c) of this Item. Registrants shall describe the nature of the services
comprising the fees disclosed under this category.

Other Fees
N/A

(e) (1) Disclose the audit committee's pre-approval policies and procedures
described in paragraph (c)(7) of Rule 2-01 of Regulation S-X.

 PIONEER FUNDS
            APPROVAL OF AUDIT, AUDIT-RELATED, TAX AND OTHER SERVICES
                       PROVIDED BY THE INDEPENDENT AUDITOR

                  SECTION I - POLICY PURPOSE AND APPLICABILITY

The Pioneer Funds recognize the importance of maintaining the independence of
their outside auditors. Maintaining independence is a shared responsibility
involving Amudi Pioneer Asset Management, Inc, the audit committee and
the independent auditors.

The Funds recognize that a Fund's independent auditors: 1) possess knowledge of
the Funds, 2) are able to incorporate certain services into the scope of the
audit, thereby avoiding redundant work, cost and disruption of Fund personnel
and processes, and 3) have expertise that has value to the Funds. As a result,
there are situations where it is desirable to use the Fund's independent
auditors for services in addition to the annual audit and where the potential
for conflicts of interests are minimal. Consequently, this policy, which is
intended to comply with Rule 210.2-01(C)(7), sets forth guidelines and
procedures to be followed by the Funds when retaining the independent audit firm
to perform audit, audit-related tax and other services under those
circumstances, while also maintaining independence.

Approval of a service in accordance with this policy for a Fund shall also
constitute approval for any other Fund whose pre-approval is required pursuant
to Rule 210.2-01(c)(7)(ii).

In addition to the procedures set forth in this policy, any non-audit services
that may be provided consistently with Rule 210.2-01 may be approved by the
Audit Committee itself and any pre-approval that may be waived in accordance
with Rule 210.2-01(c)(7)(i)(C) is hereby waived.

Selection of a Fund's independent auditors and their compensation shall be
determined by the Audit Committee and shall not be subject to this policy.



                               SECTION II - POLICY

---------------- -------------------------------- -------------------------------------------------
SERVICE           SERVICE CATEGORY DESCRIPTION      SPECIFIC PRE-APPROVED SERVICE SUBCATEGORIES
CATEGORY
---------------- -------------------------------- -------------------------------------------------
                                            
I.  AUDIT        Services that are directly       o Accounting research assistance
SERVICES         related to performing the        o SEC consultation, registration
                 independent audit of the Funds     statements, and reporting
                                                  o Tax accrual related matters
                                                  o Implementation of new accounting
                                                    standards
                                                  o Compliance letters (e.g. rating agency
                                                    letters)
                                                  o Regulatory reviews and assistance
                                                    regarding financial matters
                                                  o Semi-annual reviews (if requested)
                                                  o Comfort letters for closed end
                                                    offerings
---------------- -------------------------------- -------------------------------------------------
II.              Services which are not           o AICPA attest and agreed-upon procedures
AUDIT-RELATED    prohibited under Rule            o Technology control assessments
SERVICES         210.2-01(C)(4) (the "Rule")      o Financial reporting control assessments
                 and are related extensions of    o Enterprise security architecture
                 the audit services support the     assessment
                 audit, or use the
                 knowledge/expertise gained
                 from the audit procedures as a
                 foundation to complete the
                 project.  In most cases, if
                 the Audit-Related Services are
                 not performed by the Audit
                 firm, the scope of the Audit
                 Services would likely
                 increase.  The Services are
                 typically well-defined and
                 governed by accounting
                 professional standards (AICPA,
                 SEC, etc.)
---------------- -------------------------------- -------------------------------------------------

 ------------------------------------- ------------------------------------
                                    
   AUDIT COMMITTEE APPROVAL POLICY               AUDIT COMMITTEE
                                                REPORTING POLICY
 ------------------------------------- ------------------------------------
                                    
 o "One-time" pre-approval             o A summary of all such
   for the audit period for all          services and related fees
   pre-approved specific service         reported at each regularly
   subcategories.  Approval of the       scheduled Audit Committee
   independent auditors as               meeting.
   auditors for a Fund shall
   constitute pre approval for
   these services.
 ------------------------------------- ------------------------------------
 o "One-time" pre-approval             o A summary of all such
   for the fund fiscal year within       services and related fees
   a specified dollar limit              (including comparison to
   for all pre-approved                  specified dollar limits)
   specific service subcategories        reported quarterly.

 o Specific approval is
   needed to exceed the
   pre-approved dollar limit for
   these services (see general
   Audit Committee approval policy
   below for details on obtaining
   specific approvals)

 o Specific approval is
   needed to use the Fund's
   auditors for Audit-Related
   Services not denoted as
   "pre-approved", or
   to add a specific service
   subcategory as "pre-approved"
 ------------------------------------- ------------------------------------




                     SECTION III - POLICY DETAIL, CONTINUED

----------------------- --------------------------- -----------------------------------------------
   SERVICE CATEGORY          SERVICE CATEGORY        SPECIFIC PRE-APPROVED SERVICE SUBCATEGORIES
                               DESCRIPTION
----------------------- --------------------------- -----------------------------------------------
                                              
III. TAX SERVICES       Services which are not      o Tax planning and support
                        prohibited by the Rule,     o Tax controversy assistance
                        if an officer of the Fund   o Tax compliance, tax returns, excise
                        determines that using the     tax returns and support
                        Fund's auditor to provide   o Tax opinions
                        these services creates
                        significant synergy in
                        the form of efficiency,
                        minimized disruption, or
                        the ability to maintain a
                        desired level of
                        confidentiality.
----------------------- --------------------------- -----------------------------------------------

------------------------------------- -------------------------
  AUDIT COMMITTEE APPROVAL POLICY         AUDIT COMMITTEE
                                          REPORTING POLICY
------------------------------------- -------------------------
------------------------------------- -------------------------
o "One-time" pre-approval             o A summary of
  for the fund fiscal  year             all such services and
  within a specified dollar limit       related fees
  				        (including comparison
  			                to specified dollar
  			                limits) reported
  			                quarterly.

o Specific approval is
  needed to exceed the
  pre-approved dollar limits for
  these services (see general
  Audit Committee approval policy
  below for details on obtaining
  specific approvals)

o Specific approval is
  needed to use the Fund's
  auditors for tax services not
  denoted as pre-approved, or to add a specific
  service subcategory as
  "pre-approved"
------------------------------------- -------------------------




                     SECTION III - POLICY DETAIL, CONTINUED

----------------------- --------------------------- -----------------------------------------------
   SERVICE CATEGORY          SERVICE CATEGORY        SPECIFIC PRE-APPROVED SERVICE SUBCATEGORIES
                               DESCRIPTION
----------------------- --------------------------- -----------------------------------------------
                                              
IV.  OTHER SERVICES     Services which are not      o Business Risk Management support
                        prohibited by the Rule,     o Other control and regulatory
A. SYNERGISTIC,         if an officer of the Fund     compliance projects
UNIQUE QUALIFICATIONS   determines that using the
                        Fund's auditor to provide
                        these services creates
                        significant synergy in
                        the form of efficiency,
                        minimized disruption,
                        the ability to maintain a
                        desired level of
                        confidentiality, or where
                        the Fund's auditors
                        posses unique or superior
                        qualifications to provide
                        these services, resulting
                        in superior value and
                        results for the Fund.
----------------------- --------------------------- -----------------------------------------------

--------------------------------------- ------------------------
    AUDIT COMMITTEE APPROVAL POLICY         AUDIT COMMITTEE
                                            REPORTING POLICY
------------------------------------- --------------------------
                                   
o "One-time" pre-approval             o A summary of
  for the fund fiscal year within       all such services and
  a specified dollar limit              related fees
  			               (including comparison
  			                to specified dollar
  				        limits) reported
                                        quarterly.
o Specific approval is
  needed to exceed the
  pre-approved dollar limits for
  these services (see general
  Audit Committee approval policy
  below for details on obtaining
  specific approvals)

o Specific approval is
  needed to use the Fund's
  auditors for "Synergistic" or
  "Unique Qualifications" Other
  Services not denoted as
  pre-approved to the left, or to
  add a specific service
  subcategory as "pre-approved"
------------------------------------- --------------------------




                     SECTION III - POLICY DETAIL, CONTINUED

----------------------- ------------------------- -----------------------------------------------
   SERVICE CATEGORY         SERVICE CATEGORY        SPECIFIC PROHIBITED SERVICE SUBCATEGORIES
                              DESCRIPTION
----------------------- ------------------------- -----------------------------------------------
                                            
PROHIBITED  SERVICES    Services which result     1. Bookkeeping or other services
                        in the auditors losing       related to the accounting records or
                        independence status          financial statements of the audit
                        under the Rule.              client*
                                                  2. Financial information systems design
                                                     and implementation*
                                                  3. Appraisal or valuation services,
                                                     fairness* opinions, or
                                                     contribution-in-kind reports
                                                  4. Actuarial services (i.e., setting
                                                     actuarial reserves versus actuarial
                                                     audit work)*
                                                  5. Internal audit outsourcing services*
                                                  6. Management functions or human
                                                     resources
                                                  7. Broker or dealer, investment
                                                     advisor, or investment banking services
                                                  8. Legal services and expert services
                                                     unrelated to the audit
                                                  9. Any other service that the Public
                                                     Company Accounting Oversight Board
                                                     determines, by regulation, is
                                                     impermissible
----------------------- ------------------------- -----------------------------------------------

------------------------------------------- ------------------------------
     AUDIT COMMITTEE APPROVAL POLICY               AUDIT COMMITTEE
                                                  REPORTING POLICY
------------------------------------------- ------------------------------
o These services are not to be              o A summary of all
  performed with the exception of the(*)      services and related
  services that may be permitted              fees reported at each
  if they would not be subject to audit       regularly scheduled
  procedures at the audit client (as          Audit Committee meeting
  defined in rule 2-01(f)(4)) level           will serve as continual
  the firm providing the service.             confirmation that has
  				              not provided any
                                              restricted services.
------------------------------------------- ------------------------------

--------------------------------------------------------------------------------
GENERAL AUDIT COMMITTEE APPROVAL POLICY:
o For all projects, the officers of the Funds and the Fund's auditors will each
  make an assessment to determine that any proposed projects will not impair
  independence.

o Potential services will be classified into the four non-restricted service
  categories and the "Approval of Audit, Audit-Related, Tax and Other
  Services" Policy above will be applied. Any services outside the specific
  pre-approved service subcategories set forth above must be specifically
  approved by the Audit Committee.

o At least quarterly, the Audit Committee shall review a report summarizing the
  services by service category, including fees, provided by the Audit firm as
  set forth in the above policy.

--------------------------------------------------------------------------------


    (2) Disclose the percentage of services described in each of paragraphs (b)
   through (d) of this Item that were approved by the audit committee pursuant
   to paragraph (c)(7)(i)(C) of Rule 2-01 of Regulation S-X.

Non-Audit Services
N/A


(f) If greater than 50 percent, disclose the percentage of hours expended on the
principal accountants engagement to audit the registrant's financial statements
for the most recent fiscal year that were attributed to work performed by
persons other than the principal accountant's full-time, permanent employees.

N/A

(g) Disclose the aggregate non-audit fees billed by the registrants accountant
for services rendered to the registrant, and rendered to the registrants
investment adviser (not including any sub-adviser whose role is primarily
portfolio management and is subcontracted with or overseen by another investment
adviser), and any entity controlling, controlled by, or under common control
with the adviser that provides ongoing services to the registrant for each of
the last two fiscal years of the registrant.

N/A

(h) Disclose whether the registrants audit committee of the board of trustees
has considered whether the provision of non-audit services that were rendered to
the registrants investment adviser (not including any subadviser whose role is
primarily portfolio management and is subcontracted with or overseen by another
investment adviser), and any entity controlling, controlled by, or under common
control with the investment adviser that provides ongoing services to the
registrant that were not pre-approved pursuant to paragraph (c)(7)(ii) of
Rule 2-01 of Regulation S-X is compatible with maintaining the principal
accountant's independence.

The Fund's audit committee of the Board of Trustees
has considered whether the provision of non-audit
services that were rendered to the Affiliates (as
defined) that were not pre- approved pursuant to
paragraph (c)(7)(ii) of Rule 2-01 of Regulation S-X is
compatible with maintaining the principal accountant's
independence.

ITEM 5. AUDIT COMMITTEE OF LISTED REGISTRANTS

(a) If the registrant is a listed issuer as defined in Rule 10A-3
under the Exchange Act (17 CFR 240.10A-3), state whether
or not the registrant has a separately-designated standing
 audit committee established in accordance with Section
3(a)(58)(A) of the Exchange Act (15 U.S.C. 78c(a)(58)(A)).
If the registrant has such a committee, however designated,
identify each committee member. If the entire board of directors
is acting as the registrant's audit committee as specified in
Section 3(a)(58)(B) of the Exchange Act (15 U.S.C. 78c(a)(58)(B)),
so state.

N/A

(b) If applicable, provide the disclosure required by Rule 10A-3(d)
under the Exchange Act (17 CFR 240.10A-3(d)) regarding an exemption
from the listing standards for audit committees.

N/A

ITEM 6. SCHEDULE OF INVESTMENTS.

File Schedule of Investments in securities of unaffiliated issuers
as of the close of the reporting period as set forth in 210.1212
of Regulation S-X [17 CFR 210.12-12], unless the schedule is
included as part of the report to shareholders filed under Item
1 of this Form.

Included in Item 1


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

A closed-end management investment company that is filing an annual report on
this Form N-CSR must, unless it invests exclusively in non-voting securities,
describe the policies and procedures that it uses to determine how to vote
proxies relating to portfolio securities, including the procedures that the
company uses when a vote presents a conflict between the interests of its
shareholders, on the one hand, and those of the company's investment adviser;
principal underwriter; or any affiliated person (as defined in Section 2(a)(3)
of the Investment Company Act of 1940 (15 U.S.C. 80a-2(a)(3)) and the rules
thereunder) of the company, its investment adviser, or its principal
underwriter, on the other. Include any policies and procedures of the company's
investment adviser, or any other third party, that the company uses, or that are
used on the company's behalf, to determine how to vote proxies relating to
portfolio securities.

Not applicable to open-end management investment companies.



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

(a) If the registrant is a closed-end management investment company that
is filing an annual report on this Form N-CSR,provide the following
information:
(1) State the name, title, and length of service of the person or persons
employed by or associated with the registrant or an investment adviser
of the registrant who are primarily responsible for the day-to-day management
of the registrant's portfolio ("Portfolio Manager"). Also state each Portfolio
Manager's business experience during the past 5 years.


Not applicable to open-end management investment companies.


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

(a) If the registrant is a closed-end management investment company,
in the following tabular format, provide the information specified in
paragraph (b) of this Item with respect to any purchase made by or on
behalf of the registrant or any affiliated purchaser, as defined in
Rule 10b-18(a)(3) under the Exchange Act (17 CFR 240.10b-18(a)(3)), of
shares or other units of any class of the registrant's equity securities
that is registered by the registrant pursuant to Section 12 of the
Exchange Act (15 U.S.C. 781).

Not applicable to open-end management investment companies.


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

Describe any material changes to the procedures by which shareholders
may recommend nominees to the registrant's board of directors, where
those changes were implemented after the registrant last provided
disclosure in response to the requirements of Item 407(c)(2)(iv) of
Regulation S-R(17 CFR 229.407)(as required by Item 22(b)(15))
of Schedule 14A (17 CFR 240.14a-101), or this Item.


There have been no material changes to the procedures by which the
shareholders may recommend nominees to the registrant's board of
directors since the registrant last provided disclosure in response
to the requirements of Item 407(c)(2)(iv) of Regulation S-R of Schedule 14(A)
in its definitive proxy statement, or this item.


ITEM 11. CONTROLS AND PROCEDURES.

(a) Disclose the conclusions of the registrant's principal executive and
principal financials officers, or persons performing similar functions,
regarding the effectiveness of the registrant's disclosure
controls and procedures (as defined in Rule 30a-3(c) under the Act (17 CFR
270.30a-3(c))) as of a date within 90 days of the filing date of the report
that includes the disclosure required by this paragraph,
based on the evaluation of these controls and procedures required by Rule
30a-3(b) under the Act (17 CFR 270.30(a)-3(b) and Rules 13a-15(b) or 15d-15(b)
under the Exchange Act (17 CFR 240.13a-15(b) or 240.15d-15(b)).

The registrant's principal executive officer
and principal financial officer have
concluded that the registrant's disclosure
controls and procedures are effective based
on the evaluation of these controls and
procedures as of a date within 90 days of the
filing date of this report.


(b) Disclose any change in the registrant's internal control over financial
reporting (as defined in Rule 30a-3(d) under the Act (17CFR 270.30a-3(d)) that
occured during the second fiscal quarter of the period covered by this report
that has materially affected, or is reasonably likely to materially affect,
the registrant's internal control over financial reporting.

There were no significant changes in the
registrant's internal control over financial
reporting that occurred during the second
fiscal quarter of the period covered by this
report that have materially affected, or are
reasonably likely to materially affect, the
registrant's internal control over financial
reporting.

The registrant's principal executive officer and principal financial
officer, however, voluntarily are reporting the following information:

In August of 2006 the registrant's investment adviser
enhanced its internal procedures for reporting performance
information required to be included in prospectuses.
Those enhancements involved additional internal controls
over the appropriateness of performance data
generated for this purpose.  Such enhancements were made
following an internal review which identified
prospectuses relating to certain classes of shares of
a limited number of registrants where, inadvertently,
performance information not reflecting the deduction of
applicable sales charges was included. Those prospectuses
were revised, and the revised prospectuses were distributed to
shareholders.

Item 12. Disclosure of Securities Lending Activities for Closed-End
Management Investment Companies.

(a) If the registrant is a closed-end management investment company,
provide the following dollar amounts of income and compensation related
to the securities lending activities of the registrant during its most
recent fiscal year:

N/A

(1) Gross income from securities lending activities;

N/A

(2) All fees and/or compensation for each of the following securities
lending activities and related services: any share of revenue generated
by the securities lending program paid to the securities lending agent(s)
(revenue split); fees paid for cash collateral management services
(including fees deducted from a pooled cash collateral reinvestment
vehicle) that are not included in the revenue split; administrative
fees that are not included in the revenue split; fees for
indemnification that are not included in the revenue split; rebates
paid to borrowers; and any other fees relating to the securities lending
program that are not included in the revenue split, including a description
of those other fees;

N/A

(3) The aggregate fees/compensation disclosed pursuant to paragraph (2); and

N/A

(4) Net income from securities lending activities (i.e., the dollar amount in
paragraph (1) minus the dollar amount in paragraph (3)).

If a fee for a service is included in the revenue split, state that the fee
is included in the revenue split.

N/A

(b) If the registrant is a closed-end management investment company, describe
the services provided to the registrant by the securities lending agent in
the registrants most recent fiscal year.

N/A


ITEM 13. 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.



(2) A separate certification for each principal executive officer and principal
financial officer of the registrant as required by Rule 30a-2(a) under the Act
(17 CFR 270.30a-2(a)) , exactly as set forth below:

Filed herewith.





                                   SIGNATURES

                          [See General Instruction F]


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) Pioneer Series Trust II


By (Signature and Title)* /s/ Lisa M. Jones
Lisa M. Jones, President & Chief Executive Officer

Date August 29, 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 (Signature and Title)* /s/ Lisa M. Jones
Lisa M. Jones, President & Chief Executive Officer

Date August 29, 2019


By (Signature and Title)* /s/ Mark E. Bradley
Mark E. Bradley, Treasurer & Chief Accounting & Financial Officer

Date August 29, 2019

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