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 811-08547

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


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


            Terrence J. Cullen, Pioneer Investment 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:  August 31


Date of reporting period:  September 1, 2016 through Feburary 28, 2017


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 Disciplined
                        Growth Fund

--------------------------------------------------------------------------------
                        Semiannual Report | February 28, 2017
--------------------------------------------------------------------------------

                        Ticker Symbols:

                        Class A     PINDX
                        Class C     INDCX
                        Class Y     INYDX

                        [LOGO] PIONEER
                               Investments(R)



                      visit us: us.pioneerinvestments.com


Table of Contents


                                                                           
President's Letter                                                             2

Portfolio Management Discussion                                                4

Portfolio Summary                                                              9

Prices and Distributions                                                      10

Performance Update                                                            11

Comparing Ongoing Fund Expenses                                               14

Schedule of Investments                                                       16

Financial Statements                                                          20

Notes to Financial Statements                                                 27

Approval of Investment Advisory Agreement                                     35

Trustees, Officers and Service Providers                                      40


                 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 1


President's Letter

Dear Shareowner,

The 2016 calendar year featured many swings in market sentiment, both in the
equity and fixed-income markets. After a slow start to the year, the markets
began to rally in mid-February 2016 with a recovery in the prices of oil and
other commodities, as well as slow, positive progress in US employment figures.
The rally persisted throughout much of the remaining 10 months of 2016, gaining
further momentum in the second half of the year when US gross domestic product
(GDP) growth showed solid improvement during the third quarter and unemployment
continued to decline. Finally, in November, the election of Donald Trump as the
45th President of the United States sparked a dramatic late-year market upturn
that saw US equities briefly climb to all-time highs. Speculation that the new
Trump administration's policies would stimulate the US economy through reduced
taxes, less regulation, and increased government spending on infrastructure,
fueled the year-end rally. For the full 12 months ended December 31, 2016, the
Standard & Poor's 500 Index, a broad measure of US stock market performance,
returned a strong 11.9%.

In bond markets, the Federal Reserve Board's (the Fed's) 0.25% hike in the
Federal funds rate in December 2016, its first rate increase in a year,
contributed to a sell-off in US Treasuries. The pullback from Treasuries also
derived from the market's increased inflation and growth expectations under the
incoming Trump administration. Elsewhere within fixed income, corporate credit,
particularly in the high-yield segment of the market, performed well over the
fourth quarter and the full calendar year. US high-yield securities, as
measured by the Bank of America Merrill Lynch US High Yield Index, returned a
robust 17.5% for the 12 months ended December 31, 2016. The debt of
energy-related issuers drove the strong performance within high yield, as the
recovery in oil and other commodity prices, which began in February 2016,
sparked a rally in the sector. Meanwhile, the Bloomberg Barclays US Aggregate
Bond Index, which tracks the performance of Treasury and agency issues,
corporate bond issues, and mortgage-backed securities, returned 2.7% for the
same 12-month period, reflecting the relative weakness in government bonds.

The US economy's underlying fundamentals seem solid, and growth prospects for
2017 appear healthy. However, we remain concerned about risks to the economy of
potentially disruptive trade policies pursued by the Trump administration.
Barring a damaging trade war, though, we anticipate the Fed will continue to
hike short-term interest rates gradually during 2017. In addition, we expect the
Fed to consider carefully the potential economic effects of any fiscal policies
enacted by the new Trump administration and the Republican-controlled Congress.
In that regard, we believe President Trump's economic policies, if they come to
fruition, could help boost real GDP growth. However, the impact of Trump's
policies on US GDP may be greater in 2018 rather than in 2017. Still, even prior
to the late-year "Trump rally," US GDP growth appeared to settling in at a
sustainable annual pace of more than 2% as 2016 drew to a close, following some
weaker performance in the first half of the year. Continued improvement in the
employment market driven in part by gains in manufacturing output were among the
factors behind the bounce-back in GDP.

2 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17


While economic conditions inside the US appear solid, many economies around the
world continue to experience slow growth rates. Moreover, several countries in
various regions face a number of challenges in 2017 and beyond, including the
shifting geopolitics driving "Brexit" - the United Kingdom's pending exit from
the European Union - as well as related populist movements in Europe, limited
productivity gains, aging populations, and transitioning economic models in
China and other emerging markets. In recent years, global central banks have
kept interest rates at close to zero in an effort to stimulate economic growth.
While financial markets often benefited from the low rates, it now appears that
those policies may be losing their effectiveness, leaving central banks little
room to maneuver going forward. Moreover, the low interest rates have caused
government bond yields to plummet, presenting a dilemma for the income-oriented
investor.

Against this backdrop of still-low global interest rates, shifting priorities of
central banks, evolving demographics, and numerous geopolitical concerns, we
believe investors are likely to face ongoing challenges and much uncertainty
when it comes to finding opportunities for both income and capital appreciation.
While much has been made of passive investing as a possible source of stability
in this uncertain environment, it is our view that all investment decisions are
active choices. Throughout Pioneer's history, we have believed in the importance
of active management. During challenging market conditions, we view the value of
active management as even more compelling. Our experienced and tenured
investment teams focus on identifying value across global markets using
proprietary research, careful risk management, and a long-term perspective. We
believe our shareowners can benefit from the experience and tenure of our
investment teams as well as the insights generated from our extensive research
process.

As always, and particularly during times of market uncertainty, 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.

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
President and CEO
Pioneer Investment Management USA Inc.
February 28, 2017

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 Disciplined Growth Fund | Semiannual Report | 2/28/17 3


Portfolio Management Discussion | 2/28/17

The domestic equity market produced impressive gains during the six-month period
ended February 28, 2017, as stocks staged a robust rally following the November
2016 elections. In the following interview, Craig D. Sterling discusses the
factors that affected the performance of Pioneer Disciplined Growth Fund during
the six-month period. Mr. Sterling, Head of Equity Research, a senior vice
president and a portfolio manager at Pioneer, is responsible for the day-to-day
management of the Fund, along with Paul Cloonan, a senior vice president and a
portfolio manager at Pioneer, and Ashesh (Ace) Savla, a vice president and Head
of U.S. Equity Quantitative Research at Pioneer.

Q   How did the Fund perform during the six-month period ended
    February 28, 2017?

A   Pioneer Disciplined Growth Fund's Class A shares returned 6.80% at net asset
    value during the six-month period ended February 28, 2017, while the Fund's
    benchmark, the Russell 1000 Growth Index (the Russell Index), returned
    9.15%. During the same period, the average return of the 689 mutual funds
    in Lipper's Large-Cap Growth Funds category was 7.35%, and the average
    return of the 1,489 mutual funds in Morningstar's Large Growth category was
    7.84%.

Q   How would you describe the investment environment in the equity market
    during the six-month period ended February 28, 2017?

A   When the reporting period began in September 2016, global equity markets had
    already bounced back strongly from the negative, but brief fallout driven by
    the June 2016 "Brexit" vote in the United Kingdom. As the period
    progressed, uncertainty surrounding the U.S. presidential election also
    weighed on the markets as investors grappled with the potential effects
    that the election results might have on global economic growth. However,
    with non-U.S. central banks committed to policies aimed at propping up
    economic growth in their respective countries and regions, coupled with
    signs that the U.S. economy was gathering strength, market sentiment
    steadily improved. After Donald Trump's election in November 2016,
    speculation that tax reform, more infrastructure spending, and deregulation
    would be important policy initiatives during his presidency spurred renewed
    investor optimism, and, by year-end, major U.S. stock market indices had
    reached all-time highs. In December, the U.S. Federal Reserve (the Fed), in
    response to stronger economic data, increased the key Federal funds rate by
    0.25% and suggested that multiple, additional rate hikes were on the table
    for 2017.

4 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17


    In that environment, U.S. stocks delivered very positive performance during
    the six-month period, returning 10.01% as measured by the Standard & Poor's
    500 Index (the S&P 500). Meanwhile, growth stocks, as measured by the
    Fund's benchmark, the Russell Index, returned 9.15%.

Q   What were the main reasons for the Fund's underperformance of the Russell
    Index during the six-month period ended February 28, 2017?

A   The Fund delivered a healthy absolute return during the six-month period,
    but lagged the performance of the benchmark Russell Index in the sharp
    market rally that began in the aftermath of the 2016 U.S. elections, which
    raised investor hopes that corporate earnings would increase with the
    enactment of more pro-growth economic policies.

    Stock selection results were the main reason for the Fund's underperformance
    of its benchmark during the period.

    The single biggest drag on the Fund's benchmark-relative performance was a
    position in auto parts retailer O'Reilly Automotive, followed by positions
    in courier United Parcel Service (UPS), medical device company Edwards
    Lifesciences, diversified health care corporation Johnson & Johnson,
    financial market exchange company IntercontinentalExchange, and packaging
    company Sealed Air.

    O'Reilly Automotive had been one of the Fund's strongest performers in 2015,
    as its convenient locations and superior business model made it a leader in
    auto parts retail, a segment of the retail industry that has been
    relatively less vulnerable to encroachment by internet-based competitors.
    However, O'Reilly's high stock price made it less attractive in 2016, as
    investors grew concerned that rising gasoline prices appeared to be leading
    to declines in the number of miles driven, which is an important indicator
    of demand for auto parts (i.e., more accidents). Although we continue to
    consider O'Reilly a well-managed company with an impressive competitive
    position, we sold the Fund's shares in the wake of the recent difficulties
    and a less-compelling valuation. The performance of Edwards Lifesciences, a
    medical-device company specializing in heart valve systems, lagged during
    the period due to speculation that profits from its Trans-catheter Aortic
    Valve Replacement (TAVR) product might fall short of lofty expectations.
    Johnson & Johnson's share price weakened when it announced acquisition
    plans that worried investors, who felt the move suggested an unanticipated
    departure from the company's previous strategy. We liquidated the Fund's
    positions in both Edwards and Johnson & Johnson.

    In contrast, we have maintained the Fund's positions in UPS,
    IntercontinentalExchange, and Sealed Air, despite the fact that each stock
    produced disappointing share-price performance during the period. UPS

                 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 5


    underperformed during the period after announcing that it planned to
    increase capital spending to meet peak holiday demand, which raised
    concerns about the company's ability to execute its strategy successfully,
    given that e-commerce continues to expand and internet-commerce company
    Amazon.com is developing its own logistics system. However, we continue to
    believe that UPS has a sustained competitive position in e-commerce, and
    that the shares do not properly reflect that position or the company's
    ability to continue to generate solid economic profit.
    IntercontinentalExchange (ICE), which operates financial exchanges and
    offers clearing & risk management as well as a comprehensive set of data
    and technology solutions, apparently fell out of favor with the market when
    more cyclical, less defensive stocks attracted investors. Despite the
    recent setback, ICE continues to have a unique competitive position, and we
    are confident the market will continue to reward the company's shares as it
    monetizes its market power. Sealed Air, which makes product and food care
    packaging solutions, encountered delays in selling its Diversey industrial
    cleaning business, causing the market to lose patience. We still believe in
    the longer-term prospects for all three companies.

Q   What were some of the notable positive contributors to the Fund's
    benchmark-relative performance during the six-month period ended February
    28, 2017?

A   The Fund's sector positioning had a positive impact on benchmark-relative
    results during the period. In particular, our avoidance of real
    estate-related stocks, an overweight in financials, and the portfolio's
    relative underexposure to the health care sector benefited relative
    performance.

    The individual Fund investment with the greatest positive influence on
    benchmark-relative performance was a position in diversified financial
    services company Charles Schwab, followed by investments in semiconductor
    corporation Micron Technology, managed care companies Aetna and Humana,
    intermodal transportation company J.D. Hunt, and internet retailer
    Amazon.com.

    Charles Schwab, whose operations include discount brokerage, wealth
    management, and a bank, has gained a dominant position in its businesses.
    During the past six months, Schwab outperformed as investors recognized the
    potential of its ability to transfer sweep-cash from money markets to its
    bank. Schwab has also developed a unique advisory business that we believe
    can increase the company's assets under management. In addition, we believe
    Schwab should benefit from rising interest rates and potentially declining
    corporate tax rates under the new administration. Micron Technology, a
    leader in dynamic random-access memory (DRAM)

6 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17


    technologies, saw strong demand for its products during the period. We sold
    the Fund's Micron position after it had doubled in value, which raised
    concerns that the stock was approaching full price.

    In health care, we had invested the Fund in Aetna and Humana after our
    research indicated that managed care insurance providers would benefit as
    health care delivery systems in the U.S. continued to evolve. While we took
    profits and sold the Fund's investment in Aetna, we have maintained the
    portfolio's exposure to Humana, which has gained a leadership position in
    the health care market for retirees with its Medicare Advantage plans.
    Indeed, we think Humana's Medicare Advantage is the most attractive segment
    in the managed care industry.

    Transportation firm J.B. Hunt's earnings rose as pricing for trucking
    services finally began to trough after a period of extended weakness. Like
    many of the Fund's other holdings, J.B. Hunt's domestic orientation also
    would make it a primary beneficiary of any future decreases in corporate
    tax rates in the United States. Finally, Amazon.com fared well during the
    period as the company maintained its rapid expansion pace in internet-
    based retailing, and its dominant position in cloud information technology
    services.

Q   Did the Fund have any investments in derivative securities during the
    six-month period ended February 28, 2017?

A   No. The Fund had no exposure to any derivatives during the period.

Q   What is your investment outlook?

A   We are relatively confident in the outlook for U.S. stocks, even after the
    big rally that began in the wake of the November 2016 national elections. We
    think the economy should continue to grow at a moderate pace, providing a
    good backdrop for the expansion of corporate earnings. We continue to
    expect U.S.  gross domestic product (GDP) to grow at a rate between 2% and
    3% in 2017, led by consumer spending, a recovery in the industrial economy,
    and a modest increase in government spending.

    In our investment process for the Fund, we remain focused on bottom-up
    analysis, using company-specific research and our own propriety financial
    models to examine the potential for corporate profitability, and to
    evaluate that potential in a company's current market price.

    We intend to maintain our emphasis on identifying companies that are
    potential winners from longer-term secular changes in the economy. In
    information technology, for example, we have built up Fund positions in
    market-leading companies that appear able to fulfill the potential of

                 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 7


    cloud-based processing, including Microsoft, Google, and Amazon. However, we
    also remain alert for the development of any cyclical trends that may favor
    specific companies. For example, in the retail industry, we have built up
    Fund positions in companies currently benefiting from the growing
    popularity of home repair and remodeling, including hardware chain Home
    Depot, building products corporation Masco, and paint corporation Sherwin
    Williams.

Please refer to the Schedule of Investments on pages 16-19 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.

The Fund invests in a limited number of securities and, as a result, the Fund's
performance may be more volatile than the performance of other funds holding
more securities.

Investments in small and mid-sized companies may offer the potential for higher
returns, but are also subject to greater short-term price fluctuations than
larger, more established companies.

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

These risks may increase share price volatility.

Before investing, consider the product's investment objectives, risks, charges
and expenses. Contact your advisor or Pioneer Investments 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 Disciplined Growth Fund | Semiannual Report | 2/28/17


Portfolio Summary | 2/28/17

Portfolio Diversification
--------------------------------------------------------------------------------
(As a percentage of total investment portfolio)

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



                                                                        
U.S. Common Stocks                                                         96.0%
Depositary Receipts for International Stocks                                4.0%


Sector Distribution
--------------------------------------------------------------------------------
(As a percentage of equity holdings)

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



                                                                        
Information Technology                                                     36.8%
Consumer Discretionary                                                     16.4%
Industrials                                                                12.0%
Health Care                                                                11.4%
Consumer Staples                                                            8.4%
Financials                                                                  7.0%
Materials                                                                   4.8%
Telecommunication Services                                                  1.7%
Energy                                                                      1.5%


10 Largest Holdings
--------------------------------------------------------------------------------
(As a percentage of equity holdings)*



                                                                        
 1. Apple, Inc.                                                            7.62%
--------------------------------------------------------------------------------
 2. Microsoft Corp.                                                        5.39
--------------------------------------------------------------------------------
 3. Amazon.com, Inc.                                                       5.05
--------------------------------------------------------------------------------
 4. Visa, Inc.                                                             4.71
--------------------------------------------------------------------------------
 5. Illinois Tool Works, Inc.                                              4.56
--------------------------------------------------------------------------------
 6. The Home Depot, Inc.                                                   4.11
--------------------------------------------------------------------------------
 7. Alphabet, Inc. (Class A)                                               4.03
--------------------------------------------------------------------------------
 8. Intercontinental Exchange, Inc.                                        3.91
--------------------------------------------------------------------------------
 9. Taiwan Semiconductor Manufacturing Co., Ltd.                           3.91
--------------------------------------------------------------------------------
10. Alphabet, Inc. (Class C)                                               3.51
--------------------------------------------------------------------------------


*   This list excludes temporary cash investments and derivative instruments.
    The portfolio is actively managed, and current holdings may be different.
    The holdings listed should not be considered recommendations to buy or
    sell any securities listed.

                 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 9


Prices and Distributions | 2/28/17

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



--------------------------------------------------------------------------------
         Class                      2/28/17                        8/31/16
--------------------------------------------------------------------------------
                                                             
           A                        $17.24                         $17.53
--------------------------------------------------------------------------------
           C                        $15.67                         $16.08
--------------------------------------------------------------------------------
           Y                        $17.56                         $17.86
--------------------------------------------------------------------------------


Distributions per Share: 9/1/16-2/28/17
--------------------------------------------------------------------------------



--------------------------------------------------------------------------------
                           Net
                       Investment         Short-Term           Long-Term
         Class           Income          Capital Gains        Capital Gains
--------------------------------------------------------------------------------
                                                        
           A            $0.0431              $ --                $1.3539
--------------------------------------------------------------------------------
           C            $    --              $ --                $1.3539
--------------------------------------------------------------------------------
           Y            $0.0853              $ --                $1.3539
--------------------------------------------------------------------------------


The Russell 1000 Growth Index is an unmanaged measure of the performance of
large-cap U.S. growth stocks. 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 on pages 11-13.

10 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17


Performance Update | 2/28/17                                      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 Disciplined Growth Fund at public
offering price during the periods shown, compared to that of the Russell 1000
Growth Index.



Average Annual Total Returns
(As of February 28, 2017)
--------------------------------------------------------------------------------
                  Net          Public         Russell
                  Asset        Offering       1000
                  Value        Price          Growth
Period            (NAV)        (POP)          Index
--------------------------------------------------------------------------------
                                     
10 Years           8.26%        7.63%          9.07%
5 Years           12.09        10.76          13.79
1 Year            16.50         9.81          22.15
--------------------------------------------------------------------------------


Expense Ratio
(Per prospectus dated December 31, 2016)
--------------------------------------------------------------------------------
                  Gross
--------------------------------------------------------------------------------
               
                  1.13%
--------------------------------------------------------------------------------


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

Value of $10,000 Investment



                  Pioneer Disciplined             Russell 1000
                  Growth Fund                     Growth Index
                                            
2/07              $ 9,425                         $10,000
2/08              $ 9,618                         $10,040
2/09              $ 5,816                         $ 6,021
2/10              $ 8,760                         $ 9,283
2/11              $11,081                         $11,599
2/12              $11,787                         $12,483
2/13              $12,818                         $13,681
2/14              $16,492                         $17,668
2/15              $19,037                         $20,537
2/16              $17,899                         $19,500
2/17              $20,853                         $23,819


Call 1-800-225-6292 or visit us.pioneerinvestments.com 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. Returns
would have been lower had sales charges been reflected. POP returns reflect
deduction of maximum 5.75% sales charge. 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.

The Fund acquired the assets and liabilities of Pioneer Disciplined Growth Fund
("the predecessor fund") on June 7, 2013. As a result of the reorganization, the
predecessor fund's performance and financial history became the performance and
financial history of the Fund. The performance of Class A shares of the Fund is
the performance of Class A shares of the predecessor fund for periods prior to
the reorganization, and has not been restated to reflect any differences in
expenses.

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

                Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 11


Performance Update | 2/28/17                                      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 Disciplined Growth Fund during the
periods shown, compared to that of the Russell 1000 Growth Index.



Average Annual Total Returns
(As of February 28, 2017)
--------------------------------------------------------------------------------
                                              Russell
                                              1000
                  If           If             Growth
Period            Held         Redeemed       Index
--------------------------------------------------------------------------------
                                     
Life of Class
(7/16/08)          9.18%        9.18%         10.75%
5 Years           11.13        11.13          13.79
1 Year            15.49        15.49          22.15
--------------------------------------------------------------------------------


Expense Ratio
(Per prospectus dated December 31, 2016)
--------------------------------------------------------------------------------
                  Gross
--------------------------------------------------------------------------------
               
                  1.98%
--------------------------------------------------------------------------------


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

Value of $10,000 Investment



                  Pioneer Disciplined             Russell 1000
                  Growth Fund                     Growth Index
                                            
7/08              $10,000                         $10,000
2/09              $ 6,356                         $ 6,074
2/10              $ 9,490                         $ 9,366
2/11              $11,896                         $11,702
2/12              $12,541                         $12,594
2/13              $13,515                         $13,803
2/14              $17,245                         $17,825
2/15              $19,740                         $20,720
2/16              $18,402                         $19,673
2/17              $21,252                         $24,031


Call 1-800-225-6292 or visit us.pioneerinvestments.com 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. 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.

The Fund acquired the assets and liabilities of Pioneer Disciplined Growth Fund
("the predecessor fund") on June 7, 2013. As a result of the reorganization, the
predecessor fund's performance and financial history became the performance and
financial history of the Fund. The performance of Class C shares of the Fund is
the performance of Class C shares of the predecessor fund for periods prior to
the reorganization, and has not been restated to reflect any differences in
expenses.

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

12 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17


Performance Update | 2/28/17                                      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 Disciplined Growth Fund during the
periods shown, compared to that of the Russell 1000 Growth Index.



Average Annual Total Returns
(As of February 28, 2017)
--------------------------------------------------------------------------------
                                      Russell
                                      1000
                  Net Asset           Growth
Period            Value (NAV)         Index
--------------------------------------------------------------------------------
                                
10 Years           8.56%               9.07%
5 Years           12.43               13.79
1 Year            16.73               22.15
--------------------------------------------------------------------------------


Expense Ratio
(Per prospectus dated December 31, 2016)
--------------------------------------------------------------------------------
                  Gross
--------------------------------------------------------------------------------
               
                  0.86%
--------------------------------------------------------------------------------


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

Value of $5 Million Investment



                  Pioneer Disciplined             Russell 1000
                  Growth Fund                     Growth Index
                                            
2/07              $ 5,000,000                     $ 5,000,000
2/08              $ 5,101,566                     $ 5,020,068
2/09              $ 3,090,020                     $ 3,010,387
2/10              $ 4,670,387                     $ 4,641,712
2/11              $ 5,934,729                     $ 5,799,499
2/12              $ 6,327,247                     $ 6,241,429
2/13              $ 6,907,805                     $ 6,840,421
2/14              $ 8,909,798                     $ 8,833,957
2/15              $10,323,423                     $10,268,583
2/16              $ 9,736,732                     $ 9,749,774
2/17              $11,365,919                     $11,909,422


Call 1-800-225-6292 or visit us.pioneerinvestments.com 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.

The Fund acquired the assets and liabilities of Pioneer Disciplined Growth Fund
("the predecessor fund") on June 7, 2013. As a result of the reorganization, the
predecessor fund's performance and financial history became the performance and
financial history of the Fund. The performance of Class Y shares of the Fund is
the performance of Class Y shares of the predecessor fund for periods prior to
the reorganization, and has not been restated to reflect any differences in
expenses. Performance shown for periods prior to the inception of Class Y shares
of the predecessor fund on July 31, 2008, is the net asset value performance
of the predecessor fund's Class A shares, which has not been restated to reflect
any differences in expenses, including Rule 12b-1 fees applicable to Class A
shares. Since fees for Class A shares generally are higher than those of Class Y
shares, the performance of Class Y shares of the predecessor fund prior to their
inception on July 31, 2008, would have been higher than the performance shown.

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 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 Disciplined Growth Fund | Semiannual Report | 2/28/17 13


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 Disciplined Growth Fund

Based on actual returns from September 1, 2016, through February 28, 2017.



--------------------------------------------------------------------------------
Share Class                          A                   C                 Y
--------------------------------------------------------------------------------
                                                              
Beginning Account                $1,000.00           $1,000.00         $1,000.00
Value on 9/1/16
--------------------------------------------------------------------------------
Ending Account                   $1,068.00           $1,063.60         $1,068.60
Value (after expenses)
on 2/28/17
--------------------------------------------------------------------------------
Expenses Paid                    $    5.64           $    9.93         $    4.36
During Period*
--------------------------------------------------------------------------------


*   Expenses are equal to the Fund's annualized net expense ratio of 1.10%,
    1.94% and 0.85% 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).

14 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17


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), or redemption fees 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 Disciplined Growth Fund

Based on a hypothetical 5% return per year before expenses, reflecting the
period from September 1, 2016, through February 28, 2017.



--------------------------------------------------------------------------------
Share Class                          A                   C                 Y
--------------------------------------------------------------------------------
                                                              
Beginning Account                $1,000.00           $1,000.00         $1,000.00
Value on 9/1/16
--------------------------------------------------------------------------------
Ending Account                   $1,019.34           $1,015.17         $1,020.58
Value (after expenses)
on 2/28/17
--------------------------------------------------------------------------------
Expenses Paid                    $    5.51           $    9.69         $    4.26
During Period*
--------------------------------------------------------------------------------


*   Expenses are equal to the Fund's annualized net expense ratio of 1.10%,
    1.94% and 0.85% 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 Disciplined Growth Fund | Semiannual Report | 2/28/17 15


Schedule of Investments | 2/28/17 (unaudited)



------------------------------------------------------------------------------------------------
Shares                                                                            Value
------------------------------------------------------------------------------------------------
                                                                            
                      COMMON STOCKS -- 99.9%
                      ENERGY -- 1.0%
                      Oil & Gas Exploration & Production -- 1.0%
     503,344          Cabot Oil & Gas Corp.                                       $   11,023,234
                                                                                  --------------
                      Total Energy                                                $   11,023,234
------------------------------------------------------------------------------------------------
                      MATERIALS -- 4.9%
                      Specialty Chemicals -- 2.9%
     101,514          The Sherwin-Williams Co.                                    $   31,321,130
------------------------------------------------------------------------------------------------
                      Paper Packaging -- 2.0%
     478,368          Sealed Air Corp.                                            $   22,234,545
                                                                                  --------------
                      Total Materials                                             $   53,555,675
------------------------------------------------------------------------------------------------
                      CAPITAL GOODS -- 6.0%
                      Building Products -- 1.5%
     481,214          Masco Corp.                                                 $   16,255,409
------------------------------------------------------------------------------------------------
                      Industrial Machinery -- 4.5%
     379,336          Illinois Tool Works, Inc.                                   $   50,076,145
                                                                                  --------------
                      Total Capital Goods                                         $   66,331,554
------------------------------------------------------------------------------------------------
                      TRANSPORTATION -- 6.0%
                      Air Freight & Logistics -- 2.6%
     274,385          United Parcel Service, Inc. (Class B)                       $   29,018,958
------------------------------------------------------------------------------------------------
                      Trucking -- 3.4%
     379,151          JB Hunt Transport Services, Inc.                            $   37,221,254
                                                                                  --------------
                      Total Transportation                                        $   66,240,212
------------------------------------------------------------------------------------------------
                      CONSUMER SERVICES -- 3.2%
                      Restaurants -- 3.2%
     609,698          Starbucks Corp.                                             $   34,673,525
                                                                                  --------------
                      Total Consumer Services                                     $   34,673,525
------------------------------------------------------------------------------------------------
                      MEDIA -- 3.1%
                      Cable & Satellite -- 3.1%
     902,484          Comcast Corp.                                               $   33,770,951
                                                                                  --------------
                      Total Media                                                 $   33,770,951
------------------------------------------------------------------------------------------------
                      RETAILING -- 10.2%
                      Internet Retail -- 5.0%
      65,539          Amazon.com, Inc.*                                           $   55,383,077
------------------------------------------------------------------------------------------------
                      Home Improvement Retail -- 4.1%
     311,091          The Home Depot, Inc.                                        $   45,080,197
------------------------------------------------------------------------------------------------
                      Automotive Retail -- 1.1%
      75,382          Advance Auto Parts, Inc.                                    $   11,805,575
                                                                                  --------------
                      Total Retailing                                             $  112,268,849
------------------------------------------------------------------------------------------------


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

16 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17




------------------------------------------------------------------------------------------------
Shares                                                                            Value
------------------------------------------------------------------------------------------------
                                                                            
                      FOOD & STAPLES RETAILING -- 2.9%
                      Drug Retail -- 2.9%
     396,227          CVS Health Corp.                                            $   31,927,972
                                                                                  --------------
                      Total Food & Staples Retailing                              $   31,927,972
------------------------------------------------------------------------------------------------
                      FOOD, BEVERAGE & TOBACCO -- 5.5%
                      Brewers -- 2.0%
     220,813          Molson Coors Brewing Co. (Class B)                          $   22,167,417
------------------------------------------------------------------------------------------------
                      Packaged Foods & Meats -- 3.5%
     114,253          McCormick & Co., Inc.                                       $   11,244,780
     251,793          The Hershey Co.                                                 27,281,772
                                                                                  --------------
                                                                                  $   38,526,552
                                                                                  --------------
                      Total Food, Beverage & Tobacco                              $   60,693,969
------------------------------------------------------------------------------------------------
                      HEALTH CARE EQUIPMENT & SERVICES -- 6.2%
                      Health Care Supplies -- 3.2%
     173,512          The Cooper Companies, Inc.                                  $   34,553,180
------------------------------------------------------------------------------------------------
                      Managed Health Care -- 3.0%
     158,358          Humana, Inc.                                                $   33,453,128
                                                                                  --------------
                      Total Health Care Equipment & Services                      $   68,006,308
------------------------------------------------------------------------------------------------
                      PHARMACEUTICALS, BIOTECHNOLOGY & LIFE
                      SCIENCES -- 5.3%
                      Biotechnology -- 5.3%
     174,060          Alder Biopharmaceuticals, Inc.                              $    3,977,271
     206,727          Celgene Corp.*                                                  25,532,852
     314,098          Vertex Pharmaceuticals, Inc.*                                   28,463,561
                                                                                  --------------
                                                                                  $   57,973,684
                                                                                  --------------
                      Total Pharmaceuticals, Biotechnology & Life Sciences        $   57,973,684
------------------------------------------------------------------------------------------------
                      DIVERSIFIED FINANCIALS -- 7.0%
                      Specialized Finance -- 3.9%
     751,479          Intercontinental Exchange, Inc.                             $   42,931,995
------------------------------------------------------------------------------------------------
                      Investment Banking & Brokerage -- 3.1%
     840,391          The Charles Schwab Corp.                                    $   33,960,200
                                                                                  --------------
                      Total Diversified Financials                                $   76,892,195
------------------------------------------------------------------------------------------------
                      SOFTWARE & SERVICES -- 22.3%
                      Internet Software & Services -- 10.9%
      52,334          Alphabet, Inc. (Class A)                                    $   44,218,567
      46,793          Alphabet, Inc. (Class C)                                        38,520,466
   1,082,374          eBay, Inc.*                                                     36,692,479
                                                                                  --------------
                                                                                  $  119,431,512
------------------------------------------------------------------------------------------------
                      IT Consulting & Other Services -- 1.3%
     246,542          Cognizant Technology Solutions Corp.*                       $   14,612,544
------------------------------------------------------------------------------------------------


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

                Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 17


Schedule of Investments | 2/28/17 (unaudited) (continued)



------------------------------------------------------------------------------------------------
Shares                                                                            Value
------------------------------------------------------------------------------------------------
                                                                            
                      Data Processing & Outsourced Services -- 4.7%
     587,914          Visa, Inc.                                                  $   51,701,157
------------------------------------------------------------------------------------------------
                      Systems Software -- 5.4%
     924,470          Microsoft Corp.                                             $   59,147,591
                                                                                  --------------
                      Total Software & Services                                   $  244,892,804
------------------------------------------------------------------------------------------------
                      TECHNOLOGY HARDWARE & EQUIPMENT -- 10.6%
                      Computer Storage & Peripherals -- 7.6%
     610,582          Apple, Inc.                                                 $   83,643,625
------------------------------------------------------------------------------------------------
                      Technology Distributors -- 3.0%
     561,885          CDW Corp./DE                                                $   33,095,026
                                                                                  --------------
                      Total Technology Hardware & Equipment                       $  116,738,651
------------------------------------------------------------------------------------------------
                      SEMICONDUCTORS & SEMICONDUCTOR EQUIPMENT -- 3.9%
                      Semiconductors -- 3.9%
   1,363,684          Taiwan Semiconductor Manufacturing Co., Ltd. (A.D.R.)       $   42,915,135
                                                                                  --------------
                      Total Semiconductors & Semiconductor Equipment              $   42,915,135
------------------------------------------------------------------------------------------------
                      TELECOMMUNICATION SERVICES -- 1.8%
                      Integrated Telecommunication Services -- 1.8%
     395,639          Verizon Communications, Inc.                                $   19,635,564
                                                                                  --------------
                      Total Telecommunication Services                            $   19,635,564
------------------------------------------------------------------------------------------------
                      TOTAL COMMON STOCKS
                      (Cost $856,482,747)                                         $1,097,540,282
------------------------------------------------------------------------------------------------
                      TOTAL INVESTMENT IN SECURITIES -- 99.9%
                      (Cost $856,482,747) (a)                                     $1,097,540,282
------------------------------------------------------------------------------------------------
                      OTHER ASSETS & LIABILITIES -- 0.1%                          $    1,596,830
------------------------------------------------------------------------------------------------
                      TOTAL NET ASSETS -- 100.0%                                  $1,099,137,112
================================================================================================


*          Non-income producing security.

(A.D.R.)   American Depositary Receipts.

(a)        At February 28, 2017, the net unrealized appreciation on investments
           based on cost for federal income tax purposes of $857,591,130 was as
           follows:



                                                                             
             Aggregate gross unrealized appreciation for all investments in
                which there is an excess of value over tax cost                 $243,961,365

             Aggregate gross unrealized depreciation for all investments in
                which there is an excess of tax cost over value                   (4,012,213)
                                                                                ------------
             Net unrealized appreciation                                        $239,949,152
                                                                                ============


Purchases and sales of securities (excluding temporary cash investments) for the
six months ended February 28, 2017, aggregated $422,055,684 and $439,659,733,
respectively.

The Fund is permitted to engage in purchase and sale transactions ("cross
trades") with certain Funds and accounts for which Pioneer Investment
Management, Inc. (PIM) 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.

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

18 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17


During the six months ended February 28, 2017, the Fund engaged in purchases and
sales pursuant to these procedures amounting to $-- and $18,955,996,
respectively, which resulted in a net realized gain/loss of $293,559.

Various inputs are used in determining the value of the Fund's investments.
These inputs are summarized in the three broad levels listed 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 risk,
             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 February 28, 2017, in
valuing the Fund's investments:



--------------------------------------------------------------------------------
                     Level 1           Level 2      Level 3       Total
--------------------------------------------------------------------------------
                                                      
Common Stocks        $1,097,540,282    $--          $--           $1,097,540,282
--------------------------------------------------------------------------------
Total                $1,097,540,282    $--          $--           $1,097,540,282
================================================================================


During the six months ended February 28, 2017, there were no transfers between
Levels 1, 2 and 3.

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

                Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 19


Statement of Assets and Liabilities | 2/28/17 (unaudited)



                                                               
ASSETS:
  Investment in securities (cost $856,482,747)                    $1,097,540,282
  Cash                                                                 3,326,857
  Receivables --
     Fund shares sold                                                     82,497
     Dividends                                                         1,212,264
  Other assets                                                            59,871
--------------------------------------------------------------------------------
        Total assets                                              $1,102,221,771
================================================================================
LIABILITIES:
  Payables --
     Investment securities purchased                              $    2,097,254
     Fund shares repurchased                                             591,816
     Federal registration expense payable                                 54,942
  Due to affiliates                                                      111,733
  Trustee fees                                                             8,062
  Accrued expenses                                                       220,852
--------------------------------------------------------------------------------
        Total liabilities                                         $    3,084,659
================================================================================
NET ASSETS:
  Paid-in capital                                                 $  837,221,412
  Undistributed net investment income                                    527,396
  Accumulated net realized gain on investments                        20,330,769
  Net unrealized appreciation on investments                         241,057,535
--------------------------------------------------------------------------------
        Total net assets                                          $1,099,137,112
================================================================================
NET ASSET VALUE PER SHARE:
(No par value, unlimited number of shares authorized)
  Class A (based on $1,033,601,904/59,967,041 shares)             $        17.24
  Class C (based on $20,510,859/1,309,214 shares)                 $        15.67
  Class Y (based on $45,024,349/2,563,477 shares)                 $        17.56
MAXIMUM OFFERING PRICE:
  Class A ($17.24 (divided by) 94.25%)                            $        18.29
================================================================================


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

20 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17


Statement of Operations (unaudited)

For the Six Months Ended 2/28/17


                                                                               
INVESTMENT INCOME:
  Dividends                                                      $     6,939,702
  Interest                                                                 6,145
------------------------------------------------------------------------------------------------
        Total investment income                                                      $ 6,945,847
------------------------------------------------------------------------------------------------
EXPENSES:
  Management fees                                                $     3,386,330
  Transfer agent fees
     Class A                                                             411,593
     Class C                                                              19,526
     Class Y                                                              25,518
  Distribution fees
     Class A                                                           1,229,214
     Class C                                                             100,013
  Shareholder communications expense                                     212,346
  Administrative expense                                                 278,796
  Custodian fees                                                           6,751
  Registration fees                                                       27,476
  Professional fees                                                       25,987
  Printing expense                                                         7,631
  Fees and expenses of nonaffiliated Trustees                             22,800
  Miscellaneous                                                           45,191
------------------------------------------------------------------------------------------------
        Total expenses                                                               $ 5,799,172
-----------------------------------------------------------------------------------------------
           Net investment income                                                     $ 1,146,675
------------------------------------------------------------------------------------------------
REALIZED AND UNREALIZED GAIN (LOSS) ON INVESTMENTS:
  Net realized gain (loss) on investments                                            $25,864,432
------------------------------------------------------------------------------------------------
  Change in net unrealized appreciation (depreciation)
     on investments                                                                  $43,190,942
------------------------------------------------------------------------------------------------
  Net realized and unrealized gain (loss) on investments                             $69,055,374
------------------------------------------------------------------------------------------------
  Net increase in net assets resulting from operations                               $70,202,049
================================================================================================


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

                Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 21


Statements of Changes in Net Assets



-----------------------------------------------------------------------------------------------
                                                            Six Months
                                                            Ended 2/28/17      Year Ended
                                                            (unaudited)        8/31/16
-----------------------------------------------------------------------------------------------
                                                                         
FROM OPERATIONS:
Net investment income (loss)                                $       1,146,675  $      3,836,673
Net realized gain (loss) on investments                            25,864,432        76,770,271
Change in net unrealized appreciation (depreciation)
  on investments                                                   43,190,942       (8,070,036)
-----------------------------------------------------------------------------------------------
      Net increase in net assets resulting from operations  $      70,202,049  $     72,536,908
===============================================================================================
DISTRIBUTIONS TO SHAREOWNERS:
Net investment income:
      Class A ($0.04 and $0.05 per share, respectively)     $      (2,602,801) $    (3,002,270)
      Class Y ($0.09 and $0.11 per share, respectively)              (222,001)        (218,041)
Net realized gain:
      Class A ($1.35 and $1.00 per share, respectively)         (75,838,049)       (55,189,396)
      Class C ($1.35 and $1.00 per share, respectively)          (1,681,538)        (1,403,033)
      Class Y ($1.35 and $1.00 per share, respectively)          (3,248,377)        (1,967,556)
-----------------------------------------------------------------------------------------------
         Total distributions to shareowners                 $   (83,592,766)   $   (61,780,296)
===============================================================================================
FROM FUND SHARE TRANSACTIONS:
Net proceeds from sale of shares                            $      29,002,375  $     68,722,405
Reinvestment of distributions                                      82,614,373        60,988,525
Cost of shares repurchased                                        (56,321,520)     (113,614,415)
-----------------------------------------------------------------------------------------------
      Net increase in net assets resulting from
         Fund share transactions                            $      55,295,228  $     16,096,515
-----------------------------------------------------------------------------------------------
      Net increase in net assets                            $      41,904,511  $     26,853,127
NET ASSETS:
Beginning of period                                         $  1,057,232,601   $  1,030,379,474
-----------------------------------------------------------------------------------------------
End of period                                               $  1,099,137,112   $  1,057,232,601
-----------------------------------------------------------------------------------------------
Undistributed net investment income                         $        527,396   $      2,205,523
===============================================================================================


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

22 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17




-----------------------------------------------------------------------------------------------
                                  Six Months     Six Months
                                  Ended          Ended
                                  2/28/17        2/28/17            Year Ended   Year Ended
                                  Shares         Amount             8/31/16      8/31/16
                                  (unaudited)    (unaudited)        Shares       Amount
-----------------------------------------------------------------------------------------------
                                                                     
Class A
Shares sold                        1,338,655     $  22,615,741      2,881,007    $   49,095,074
Reinvestment of distributions      4,766,798        77,690,076      3,298,673        57,586,443
Less shares repurchased           (2,828,739)      (48,015,545)    (5,628,365)      (96,294,767)
-----------------------------------------------------------------------------------------------
      Net increase                 3,276,714     $  52,290,272        551,315    $   10,386,750
===============================================================================================
Class C
Shares sold                           73,796     $   1,133,872        200,413    $    3,160,251
Reinvestment of distributions        106,687         1,578,966         81,888         1,317,581
Less shares repurchased             (163,214)       (2,521,917)      (422,802)       (6,511,902)
-----------------------------------------------------------------------------------------------
      Net increase (decrease)         17,269     $     190,921       (140,501)   $   (2,034,070)
===============================================================================================
Class Y
Shares sold                          305,030     $   5,252,762        978,917    $   16,467,080
Reinvestment of distributions        200,995         3,345,331        117,169         2,084,501
Less shares repurchased             (335,124)       (5,784,058)      (621,631)      (10,807,746)
-----------------------------------------------------------------------------------------------
      Net increase                   170,901     $   2,814,035        474,455    $    7,743,835
===============================================================================================


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

                Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 23


Financial Highlights



------------------------------------------------------------------------------------------------------------------------------------
                                                   Six Months
                                                   Ended           Year            Year         Year        Year         Year
                                                   2/28/17         Ended           Ended        Ended       Ended        Ended
                                                   (unaudited)     8/31/16         8/31/15      8/31/14     8/31/13 (a)  8/31/12 (a)
----------------------------------------------------------------------------------------------------------------------------------
                                                                                                       
Class A
Net asset value, beginning of period               $     17.53     $     17.34     $    17.93   $  14.27    $    13.93   $    12.96
------------------------------------------------------------------------------------------------------------------------------------
Increase (decrease) from investment operations:
   Net investment income (loss)                    $      0.02(b)  $      0.06(b)  $     0.05   $   0.17    $     0.06   $     0.03
   Net realized and unrealized gain (loss) on
   investments                                            1.08            1.18           0.43       3.52          2.13         2.03
------------------------------------------------------------------------------------------------------------------------------------
Net increase (decrease) from investment
   operations                                      $      1.10     $      1.24     $     0.48   $   3.69    $     2.19   $     2.06
------------------------------------------------------------------------------------------------------------------------------------
Distributions to shareowners:
   Net investment income                           $     (0.04)    $     (0.05)    $    (0.16)  $  (0.03)   $    (0.08)  $    (0.04)
   Net realized gain                                     (1.35)          (1.00)         (0.91)        --         (1.77)       (1.05)
------------------------------------------------------------------------------------------------------------------------------------
Total distributions                                $     (1.39)    $     (1.05)    $    (1.07)  $  (0.03)   $    (1.85)  $    (1.09)
------------------------------------------------------------------------------------------------------------------------------------
Net increase (decrease) in net asset value         $     (0.29)    $      0.19     $    (0.59)  $   3.66    $     0.34   $     0.97
------------------------------------------------------------------------------------------------------------------------------------
Net asset value, end of period                     $     17.24     $     17.53     $    17.34   $  17.93    $    14.27   $    13.93
====================================================================================================================================
Total return*                                             6.80%           7.18%          2.58%     25.89%        16.57%       17.46%
Ratio of net expenses to average net assets               1.10%**         1.13%          1.14%      1.18%         1.23%        1.25%
Ratio of net investment income (loss) to average
   net assets                                             0.23%**         0.38%          0.33%      1.01%         0.26%        0.31%
Portfolio turnover rate                                     81%**          118%            49%        47%           45%          75%
Net assets, end of period (in thousands)           $ 1,033,602     $   993,736     $  973,492   $998,718    $  846,042   $    9,646
Ratios with no waiver of fees and assumption of
   expenses by PIM and no reduction for fees paid
   indirectly:
   Total expenses to average net assets                   1.10%**         1.13%          1.14%      1.18%         1.26%        1.48%
   Net investment income (loss) to average net
   assets                                                 0.23%**         0.38%          0.33%      1.01%         0.23%        0.08%
====================================================================================================================================


(a) The Fund acquired the assets and liabilities of Pioneer Disciplined Growth
    Fund (the "predecessor fund") on June 7, 2013 (the "reorganization"). As a
    result of the reorganization, the predecessor fund's performance and
    financial history became the performance and financial history of the Fund.
    Historical per-share amounts prior to June 7, 2013 have been adjusted to
    reflect the conversion ratio used to align the net asset values of the
    predecessor fund with those of the Fund.

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

*   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 and no sales
    charges. Total return would be reduced if sales charges were taken into
    account.

**  Annualized.

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

24 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17




------------------------------------------------------------------------------------------------------------------------------------
                                                   Six Months
                                                   Ended           Year            Year          Year       Year         Year
                                                   2/28/17         Ended           Ended         Ended      Ended        Ended
                                                   (unaudited)     8/31/16         8/31/15       8/31/14    8/31/13 (a)  8/31/12 (a)
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                       
Class C
Net asset value, beginning of period               $ 16.08         $ 16.07         $ 16.72      $  13.40    $   13.17    $   12.35
------------------------------------------------------------------------------------------------------------------------------------
Increase (decrease) from investment operations:
   Net investment income (loss)                    $ (0.05)(b)(c)  $ (0.08)(b)(c)  $ (0.09)(c)  $   0.03    $   (0.05)   $   (0.08)
   Net realized and unrealized gain (loss) on
   investments                                        0.99            1.09            0.40          3.29         2.00         1.92
------------------------------------------------------------------------------------------------------------------------------------
Net increase (decrease) from investment operations $  0.94         $  1.01         $  0.31      $   3.32    $    1.95    $    1.84
------------------------------------------------------------------------------------------------------------------------------------
Distributions to shareowners:
   Net investment income                           $    --         $    --         $ (0.05)     $     --    $   (1.72)   $   (1.02)
   Net realized gain                                 (1.35)          (1.00)          (0.91)           --           --           --
------------------------------------------------------------------------------------------------------------------------------------
Total distributions                                $ (1.35)        $ (1.00)        $ (0.96)     $     --    $   (1.72)   $   (1.02)
------------------------------------------------------------------------------------------------------------------------------------
Net increase (decrease) in net asset value         $ (0.41)        $  0.01         $ (0.65)     $   3.32    $    0.23    $    0.82
------------------------------------------------------------------------------------------------------------------------------------
Net asset value, end of period                     $ 15.67         $ 16.08         $ 16.07      $  16.72    $   13.40    $   13.17
====================================================================================================================================
Total return*                                         6.36%           6.26%           1.74%        24.78%       15.49%       16.41%
Ratio of net expenses to average net assets           1.94%**         1.98%           2.00%         2.04%        2.15%        2.15%
Ratio of net investment income (loss) to average
   net assets                                        (0.62)%**       (0.48)%         (0.51)%        0.15%       (0.59)%      (0.58)%
Portfolio turnover rate                                 81%**          118%             49%           47%          45%          75%
Net assets, end of period (in thousands)           $20,511         $20,776         $23,020      $ 20,453    $  17,505    $   1,501
Ratios with no waiver of fees and assumption of
   expenses by PIM and no reduction for fees paid
   indirectly:
   Total expenses to average net assets               1.94%**         1.98%           2.00%         2.04%        2.25%        2.41%
   Net investment income (loss) to average net
   assets                                            (0.62)%**       (0.48)%         (0.51)%        0.15%       (0.69)%      (0.84)%
====================================================================================================================================


(a) The Fund acquired the assets and liabilities of Pioneer Disciplined Growth
    Fund (the "predecessor fund") on June 7, 2013 (the "reorganization"). As a
    result of the reorganization, the predecessor fund's performance and
    financial history became the performance and financial history of the Fund.
    Historical per-share amounts prior to June 7, 2013 have been adjusted to
    reflect the conversion ratio used to align the net asset values of the
    predecessor fund with those of the Fund.

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

(c) The amount shown for a share outstanding does not correspond with net
    investment income on the Statement of Operations for the period due to
    timing of the sales and repurchase of shares.

*   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 and no sales
    charges. Total return would be reduced if sales charges were taken into
    account.

**  Annualized

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

                Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 25


Financial Highlights (continued)



------------------------------------------------------------------------------------------------------------------------------------
                                                   Six Months
                                                   Ended           Year            Year         Year        Year         Year
                                                   2/28/17         Ended           Ended        Ended       Ended        Ended
                                                   (unaudited)     8/31/16         8/31/15      8/31/14     8/31/13 (a)  8/31/12 (a)
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                       
Class Y
Net asset value, beginning of period               $     17.86     $    17.66      $    18.24   $  14.49    $    14.16   $    13.16
------------------------------------------------------------------------------------------------------------------------------------
Increase (decrease) from investment operations:
   Net investment income (loss)                    $      0.04(b)  $     0.11(b)   $     0.10   $   0.33    $     0.13   $     0.09
   Net realized and unrealized gain (loss) on
   investments                                            1.10           1.20            0.45       3.49          2.14         2.04
------------------------------------------------------------------------------------------------------------------------------------
Net increase (decrease) from investment operations $      1.14     $     1.31      $     0.55   $   3.82    $     2.27   $     2.13
------------------------------------------------------------------------------------------------------------------------------------
Distributions to shareowners:
   Net investment income                           $     (0.09)    $    (0.11)     $    (0.22)  $  (0.07)   $    (0.16)  $    (0.08)
   Net realized gain                                     (1.35)         (1.00)          (0.91)        --         (1.78)       (1.05)
------------------------------------------------------------------------------------------------------------------------------------
Total distributions                                $     (1.44)    $    (1.11)     $    (1.13)  $  (0.07)   $    (1.94)  $    (1.13)
------------------------------------------------------------------------------------------------------------------------------------
Net increase (decrease) in net asset value         $     (0.30)    $     0.20      $    (0.58)  $   3.75    $     0.33   $     1.00
------------------------------------------------------------------------------------------------------------------------------------
Net asset value, end of period                     $     17.56     $    17.86      $    17.66   $  18.24    $    14.49   $    14.16
====================================================================================================================================
Total return*                                             6.86%          7.46%(c)        2.93%     26.41%        16.95%       17.88%
Ratio of net expenses to average net assets               0.85%**        0.86%           0.82%      0.75%         0.90%        0.90%
Ratio of net investment income (loss) to average
   net assets                                             0.48%**        0.65%           0.70%      1.52%         0.78%        0.67%
Portfolio turnover rate                                     81%**         118%             49%        47%           45%          75%
Net assets, end of period (in thousands)           $    45,024     $   42,721      $   33,867   $ 19,818    $   28,352   $   38,296
Ratios with no waiver of fees and assumption of
   expenses by PIM and no reduction for fees paid
   indirectly:
   Total expenses to average net assets                   0.85%**        0.86%           0.82%      0.75%         0.95%        1.00%
   Net investment income (loss) to average net assets     0.48%**        0.65%           0.70%      1.52%         0.73%        0.57%
====================================================================================================================================


(a) The Fund acquired the assets and liabilities of Pioneer Disciplined Growth
    Fund (the "predecessor fund") on June 7, 2013 (the "reorganization"). As a
    result of the reorganization, the predecessor fund's performance and
    financial history became the performance and financial history of the Fund.
    Historical per-share amounts prior to June 7, 2013 have been adjusted to
    reflect the conversion ratio used to align the net asset values of the
    predecessor fund with those of the Fund.

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

(c) If the Fund had not recognized gains in settlement of class action lawsuits
    during the year ended August 31, 2016, the total return would have been
    7.40%.

*   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 and no sales
    charges. Total return would be reduced if sales charges were taken into
    account.

**  Annualized

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

26 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17


Notes to Financial Statements | 2/28/17 (unaudited)

1. Organization and Significant Accounting Policies

Pioneer Disciplined Growth Fund (the Fund) is a diversified series of Pioneer
Series Trust XII, a Delaware statutory trust. The Fund is registered under the
Investment Company Act of 1940 as a diversified, open-end management investment
company. The Fund's investment objective is to seek long-term capital growth.

The Fund offers three classes of shares designated as Class A, Class C and Class
Y shares. 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 shareholder approval. Under per-share voting, each share
of a class of the Fund is entitled to one vote. Under dollar-weighted voting, a
shareholder'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.

The Fund's financial statements have been prepared in conformity with U.S.
generally accepted accounting principles (U.S.  GAAP) that require the
management of the Fund to make estimates and assumptions that affect the
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 Fund is an investment company and follows investment company accounting and
reporting guidance under U.S. GAAP. 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.

                Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 27


    Equity securities that have traded on an exchange are valued by using the
    last sale price on the principal exchange where they are traded. Equity
    securities that have not traded on the date of valuation, or securities
    for which sale prices are not available, generally are valued using the
    mean between the last bid and asked prices or, if both last bid and asked
    prices are not available, at the last quoted bid price. Last sale and bid
    and asked prices are provided by independent third party pricing services.
    In the case of equity securities not traded on an exchange, prices are
    typically determined by independent third party pricing services using a
    variety of techniques and methods.

    The value of foreign securities is translated into U.S. dollars based on
    foreign currency exchange rate quotations supplied by a third party pricing
    source. Trading in non-U.S.  equity securities is substantially completed
    each day at various times prior to the close of the NYSE. The values of
    such securities used in computing the net asset value of the Fund's shares
    are determined as of such times. The Fund may use a fair value model
    developed by an independent pricing service to value non-U.S. equity
    securities.

    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 Pioneer Investment
    Management, Inc. (PIM), the Fund's investment adviser and a wholly owned
    indirect subsidiary of UniCredit S.p.A. (UniCredit), pursuant to
    procedures adopted by the Fund's Board of Trustees. PIM's fair valuation
    team uses fair value methods approved by the Valuation Committee of the
    Board of Trustees. PIM'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
    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 February 28, 2017, there were no securities that were valued using fair
    value methods (other than securities valued using prices supplied by
    independent pricing services).

28 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17


B.  Investment Income and Transactions

    Dividend income is recorded on the ex-dividend date except that certain
    dividends from foreign securities where the ex-dividend date may have
    passed are recorded as soon as the Fund becomes aware of the ex-dividend
    data in the exercise of reasonable diligence. Interest income is recorded
    on the accrual basis. Dividend and interest income are reported net of
    unrecoverable foreign taxes withheld at the applicable country rates.

    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 taxable income and net realized capital gains, if any, to its
    shareowners. Therefore, no provision for federal income taxes is required.
    As of August 31, 2016, 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 in the Statement of Operations. Tax
    returns filed within the prior three fiscal 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 overdistributions
    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.

    The tax character of current year distributions payable will be determined
    at the end of the current taxable year. The tax character of distributions
    during the year ended August 31, 2016 was as follows:



    ----------------------------------------------------------------------------
                                                                            2016
    ----------------------------------------------------------------------------
                                                                  
    Distributions paid from:
    Ordinary income                                                  $ 3,220,311
    Long-term capital gain                                            58,559,985
    ----------------------------------------------------------------------------
       Total                                                         $61,780,296
    ============================================================================


                Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 29


    The following shows the components of distributable earnings on a federal
    income tax-basis at August 31, 2016:



    ----------------------------------------------------------------------------
                                                                            2016
    ----------------------------------------------------------------------------
                                                                 
    Distributable earnings:
    Undistributed ordinary income                                   $  2,145,653
    Undistributed long term capital gain                              76,402,554
    Net unrealized appreciation                                      196,758,210
    ----------------------------------------------------------------------------
        Total                                                       $275,306,417
    ============================================================================


    The difference between book-basis and tax-basis net unrealized appreciation
    is attributable to the tax deferral of losses on wash sales, and adjustments
    related to other holdings.

D.  Fund Shares

    The Fund records sales and repurchases of its shares as of trade date.
    Pioneer Funds Distributor, Inc. (PFD), the principal underwriter for the
    Fund and a wholly owned indirect subsidiary of UniCredit, earned $20,142 in
    underwriting commissions on the sale of Class A shares during the year
    ended February 28, 2017.

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 (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).

    Distributions to shareowners are recorded as of the ex-dividend date.
    Distributions paid by 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.

30 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17


F.  Risks

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

2. Management Agreement

PIM manages the Fund's portfolio. Management fees are calculated daily at the
annual rate equal to 0.65% of the Fund's average daily net assets up to $1
billion, 0.60% of the next $4 billion of the Fund's average daily net assets and
0.55% of the Fund's average daily net assets over $5 billion. For the six
months ended February 28, 2017, the effective annualized management fee
(excluding waivers and/or assumption of expenses) was equivalent to 0.65% of the
Fund's average daily net assets.

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
$81,014 in management fees, administrative costs and certain other
reimbursements payable to PIM at February 28, 2017.

3. Transfer Agent

Boston Financial Data Services, 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.

In addition, the Fund reimbursed the transfer agent for out-of-pocket expenses
incurred by the transfer agent related to shareholder communications activities
such as proxy and statement mailings and outgoing phone calls. For the six
months ended February 28, 2017, such out-of-pocket expenses by class of shares
were as follows:



--------------------------------------------------------------------------------
 Shareholder Communications:
--------------------------------------------------------------------------------
                                                                     
Class A                                                                 $209,103
Class C                                                                    2,289
Class Y                                                                      954
--------------------------------------------------------------------------------
  Total                                                                 $212,346
================================================================================


                Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 31


4. Distribution Plan

The Fund has adopted a Distribution 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 PFD 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 PFD 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 $30,719 in
distribution fees payable to PFD at February 28, 2017.

In addition, redemptions of each class of shares (except Class Y 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 PFD. For the
six months ended February 28, 2017, CDSCs in the amount of $1,155 were paid to
PFD.

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
the limits set for borrowing by the Fund's prospectus and the 1940 Act. The
credit

32 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17


facility in which the Fund participated until February 9, 2016 was in the amount
of $240 million. The credit facility in which the Fund participated until
February 7, 2017, was in the amount of $220 million. Effective February 8, 2017,
the Fund participated in a facility that is in the amount of $195 million. Under
such facility, depending on the type of loan, interest on borrowings is payable
at the London Interbank Offered Rate (LIBOR) plus 0.85% 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 and (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 February 28, 2017, the Fund had no
borrowings under the credit facility.

                Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 33


ADDITIONAL INFORMATION

Pioneer Investment Management, Inc. (the "Adviser"), the Fund's investment
adviser, is currently an indirect, wholly owned subsidiary of UniCredit S.p.A.
("UniCredit"). On December 12, 2016, UniCredit announced that it has entered
into a binding agreement for the sale of its Pioneer Investments business, which
includes the Adviser, to Amundi (the "Transaction"). Amundi is headquartered in
Paris, France, and, as of September 30, 2016, had more than $1.1 trillion in
assets under management worldwide. The closing of the Transaction is expected to
happen in 2017, subject to certain regulatory and antitrust approvals, and other
conditions.

Under the Investment Company Act of 1940, the closing of the Transaction will
cause the Fund's current investment advisory agreement with the Adviser to
terminate. Accordingly, the Fund's Board of Trustees has approved a new
investment advisory agreement for the Fund, which will be submitted to the
shareholders of the Fund for their approval.

34 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17


Approval of Investment Advisory Agreement

Pioneer Investment Management, Inc. (PIM) serves as the investment adviser to
Pioneer Disciplined Growth Fund (the Fund) pursuant to an investment advisory
agreement between PIM and the Fund. In order for PIM to remain the investment
adviser of the Fund, the Trustees of the Fund must determine annually whether to
renew the investment advisory agreement for the Fund.

The contract review process began in January 2016 as the Trustees of the Fund
agreed on, among other things, an overall approach and timeline for the process.
Contract review materials were provided to the Trustees in March 2016 and May
2016. In addition, the Trustees reviewed and discussed the Fund's performance at
regularly scheduled meetings throughout the year, and took into account other
information related to the Fund provided to the Trustees at regularly scheduled
meetings, in connection with the review of the Fund's investment advisory
agreement.

In March 2016, the Trustees, among other things, discussed the memorandum
provided by Fund counsel that summarized the legal standards and other
considerations that are relevant to the Trustees in their deliberations
regarding the renewal of the investment advisory agreement, and reviewed and
discussed the qualifications of the investment management teams, as well as the
level of investment by the Fund's portfolio managers in the Fund. In May 2016,
the Trustees, among other things, reviewed the Fund's management fee and total
expense ratios, the financial statements of PIM and its parent companies, the
profitability analyses provided by PIM, and possible economies of scale. The
Trustees also reviewed the profitability of the institutional business of PIM
and PIM's affiliate, Pioneer Institutional Asset Management, Inc. (together with
PIM, "Pioneer"), as compared to that of PIM's fund management business, and
considered the differences between the fees and expenses of the Fund and the
fees and expenses of Pioneer's institutional accounts, as well as the different
services provided by PIM to the Fund and by Pioneer to the institutional
accounts. The Trustees further considered contract review materials in July and
September 2016.

At a meeting held on September 13, 2016, based on their evaluation of the
information provided by PIM and third parties, the Trustees of the Fund,
including the Independent Trustees voting separately, unanimously approved the
renewal of the investment advisory agreement for another year. In approving the
renewal of the investment advisory agreement, the Trustees considered various
factors that they determined were relevant, including the factors described
below. The Trustees did not identify any single factor as the controlling factor
in determining to approve the renewal of the agreement.

                Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 35


Nature, Extent and Quality of Services

The Trustees considered the nature, extent and quality of the services that had
been provided by PIM to the Fund, taking into account the investment objective
and strategy of the Fund. The Trustees also reviewed PIM's investment approach
for the Fund and its research process. The Trustees considered the resources of
PIM and the personnel of PIM who provide investment management services to the
Fund. They also reviewed the amount of non-Fund assets managed by the portfolio
managers of the Fund. The Trustees considered the non-investment resources and
personnel of PIM involved in PIM's services to the Fund, including PIM's
compliance and legal resources and personnel. The Trustees noted the substantial
attention and high priority given by PIM's senior management to the Pioneer fund
complex.

The Trustees considered that PIM supervises and monitors the performance of the
Fund's service providers and provides the Fund with personnel (including Fund
officers) and other resources that are necessary for the Fund's business
management and operations. The Trustees also considered that, as administrator,
PIM is responsible for the administration of the Fund's business and other
affairs. The Trustees considered the fees paid to PIM for the provision of
administration services.

Based on these considerations, the Trustees concluded that the nature, extent
and quality of services that had been provided by PIM to the Fund were
satisfactory and consistent with the terms of the investment advisory agreement.

Performance of the Fund

In considering the Fund's performance, the Trustees regularly review and discuss
throughout the year data prepared by PIM and information comparing the Fund's
performance with the performance of its peer group of funds as classified by
each of Morningstar, Inc. (Morningstar) and Lipper, and with the performance of
the Fund's benchmark index. They also discuss the Fund's performance with PIM on
a regular basis. The Trustees' regular reviews and discussions were factored
into the Trustees' deliberations concerning the renewal of the advisory
agreement.

Management Fee and Expenses

The Trustees considered information showing the fees and expenses of the Fund in
comparison to the management fees and expense ratios of its peer group of funds
as classified by Morningstar and also to the expense ratios of a peer group of
funds selected on the basis of criteria determined by the Independent Trustees
for this purpose using data provided by Strategic Insight

36 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17


Mutual Fund Research and Consulting, LLC (Strategic Insight), an independent
third party. In all quintile rankings referred to below, first quintile is most
favorable to the Fund's shareowners.

The Trustees considered that the Fund's management fee for the most recent
fiscal year was in the second quintile relative to the management fees paid by
other funds in its Morningstar peer group for the comparable period. The
Trustees also considered the breakpoints in the management fee schedule and the
reduced fee rates above certain asset levels. The Trustees considered that the
expense ratio of the Fund's Class A shares for the most recent fiscal year was
in the third quintile relative to its Morningstar peer group and in the second
quintile relative to its Strategic Insight peer group, in each case for the
comparable period. The Trustees considered the impact of transfer agency,
sub-transfer agency, and other non-management fee expenses on the expense ratios
of the Fund, and noted the impact of expenses relating to small accounts and
omnibus accounts on transfer and sub-transfer agency expenses generally. The
Trustees noted that they separately review the Fund's transfer agency, sub-
transfer agency and intermediary arrangements and that the results of the most
recent such review were considered in the consideration of the Fund's expense
ratio.

The Trustees reviewed management fees charged by Pioneer to institutional and
other clients, including publicly offered European funds sponsored by affiliates
of Pioneer, unaffiliated U.S. registered investment companies (in a sub-advisory
capacity), and unaffiliated foreign and domestic separate accounts. The Trustees
also considered PIM's costs in providing services to the Fund and Pioneer's
costs in providing services to the other clients and considered the differences
in management fees and profit margins for Fund and non-Fund services. In
evaluating the fees associated with Pioneer's client accounts, the Trustees took
into account the respective demands, resources and complexity associated with
the Fund and client accounts. The Trustees noted that, in some instances, the
fee rates for those clients were lower than the management fee for the Fund and
considered that, under the investment advisory agreement with the Fund, PIM
performs additional services for the Fund that it does not provide to those
other clients or services that are broader in scope, including oversight of the
Fund's other service providers and activities related to compliance and the
extensive regulatory and tax regimes to which the Fund is subject. The Trustees
also considered the different entrepreneurial risks associated with PIM's
management of the Fund and Pioneer's management of the other client accounts.

The Trustees concluded that the management fee payable by the Fund to PIM was
reasonable in relation to the nature and quality of the services provided by PIM
to the Fund.

                Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 37


Profitability

The Trustees considered information provided by PIM regarding the profitability
of PIM with respect to the advisory services provided by PIM to the Fund,
including the methodology used by PIM in allocating certain of its costs to the
management of the Fund. The Trustees also considered PIM's profit margin in
connection with the overall operation of the Fund. They further reviewed the
financial results, including the profit margins, realized by PIM and its
affiliates from non-fund businesses. The Trustees considered PIM's profit
margins with respect to the Fund in comparison to the limited industry data
available and noted that the profitability of any adviser was affected by
numerous factors, including its organizational structure and method for
allocating expenses. The Trustees concluded that PIM's profitability with
respect to the management of the Fund was not unreasonable.

Economies of Scale

The Trustees considered PIM's views relating to economies of scale in connection
with the Pioneer Funds as fund assets grow and the extent to which any such
economies of scale are shared with funds and fund shareholders. The Trustees
noted the breakpoints in the management fee schedule. The Trustees recognize
that economies of scale are difficult to identify and quantify, and that, among
other factors that may be relevant, are the following: fee levels, expense
subsidization, investment by PIM in research and analytical capabilities and
PIM's commitment and resource allocation to the Fund. The Trustees noted that
profitability also may be an indicator of the availability of any economies of
scale, although profitability may vary for other reasons including reductions in
expenses. The Trustees concluded that economies of scale, if any, were being
appropriately shared with the Funds.

Other Benefits

The Trustees considered the other benefits to PIM from its relationship with the
Fund. The Trustees considered the character and amount of fees paid by the Fund,
other than under the investment advisory agreement, for services provided by PIM
and its affiliates. The Trustees further considered the revenues and
profitability of PIM's businesses other than the fund business. Pioneer is the
principal U.S. asset management business of Pioneer Global Asset Management, the
worldwide asset management business of UniCredit Group, which manages over $150
billion in assets (including the Funds). Pioneer and the Funds receive
reciprocal intangible benefits from the relationship, including mutual brand
recognition and, for the Funds, direct and indirect access to the resources of a
large global asset manager. The Trustees concluded that any such benefits
received by Pioneer as a result of its relationship with the Funds were
reasonable and their consideration of the advisory agreement between the Fund
and PIM and the fees thereunder were unaffected by Pioneer's possible receipt of
any such intangible benefits.

38 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17


Conclusion

After consideration of the factors described above as well as other factors, the
Trustees, including all of the Independent Trustees, concluded that the
investment advisory agreement between PIM and the Fund, including the fees
payable thereunder, was fair and reasonable and voted to approve the proposed
renewal of the investment advisory agreement for the Fund.

                Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 39


Trustees, Officers and Service Providers

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

Investment Adviser and Administrator
Pioneer Investment Management, Inc.

Custodian and Sub-Administrator
Brown Brothers Harriman & Co.

Principal Underwriter
Pioneer Funds Distributor, Inc.

Legal Counsel
Morgan, Lewis & Bockius LLP

Shareowner Services and Transfer Agent
Boston Financial Data Services, 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 us.pioneerinvestments.com. This information is also available on the
Securities and Exchange Commission's web site at www.sec.gov.

*   Ms. Monchak is a non-voting Advisory Trustee.

40 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17


                        This page is for your notes.

                Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 41


                        This page is for your notes.

42 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17


                        This page is for your notes.

                Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17 43


                        This page is for your notes.

44 Pioneer Disciplined Growth Fund | Semiannual Report | 2/28/17


How to Contact 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

FactFone(SM) for automated fund yields, prices,
account information and transactions                              1-800-225-4321

Retirement plans information                                      1-800-622-0176

Write to us:
--------------------------------------------------------------------------------
Pioneer Funds
P.O. Box 55014
Boston, Massachusetts 02205-5014

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

Our internet e-mail address                   ask.pioneer@pioneerinvestments.com
(for general questions about Pioneer only)

Visit our web site: us.pioneerinvestments.com

This report must be preceded or accompanied by a prospectus.

The Fund files a complete schedule of investments with the Securities and
Exchange Commission for the first and third quarters for each fiscal year on
Form N-Q. Shareholders may view the filed Form N-Q by visiting the Commission's
web site at http://www.sec.gov. The filed form may also be viewed and copied at
the Commission's Public Reference Room in Washington, DC. Information regarding
the operations of the Public Reference Room may be obtained by calling
1-800-SEC-0330.


[LOGO] PIONEER
       Investments(R)

Pioneer Investment Management, Inc.
60 State Street
Boston, MA 02109
us.pioneerinvestments.com

Securities offered through Pioneer Funds Distributor, Inc.
60 State Street, Boston, MA 02109
Underwriter of Pioneer Mutual Funds, Member SIPC
(C) 2017 Pioneer Investments 19111-11-0417




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)).

Ms. Marguerite A. Piret, 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.

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 Pioneer Investment Management, Inc ("PIM"), 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.

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. 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 XII


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

Date May 1, 2017


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 May 1, 2017


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

Date May 1, 2017

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