Risk Measures

As of July 31, 2010

As compared to the Barclay High Yield Municipal Bond Index

R-squared	0.90
Beta	1.23
Sharpe Ratio	-0.03
Standard Deviation (Fund)	16.21
Standard Deviation (Benchmark)	12.47

Fund Performance

Chart represents performance through 2nd quarter 2010.

Chart is for illustrative purposes. These results represent the percentage change in net asset value per share. NAV returns would have been lower had sales charges been reflected.

For the most recent month-end performance results click here. 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. All results are historical and assume the reinvestment of dividends and capital gains.

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 Otherwise, fee waivers can be rescinded at any time.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.

AVERAGE ANNUAL TOTAL RETURNS through July 31, 2010   1-Year 3-Year 5-Year 10-Year Performance Inception Date Class A Shares (NAV) 27.20% -1.86% - - -0.16% Class A Shares (POP) 21.43% -3.36% - - -1.36% Class C Return If Held 26.13% -2.74% - - -1.11% Class C Return If Redeemed 26.13% -2.74% - - -1.11% Class Y Shares (NAV) 26.72% -2.16% - - -0.46% Lipper High Yield Municipal Debt Funds Average 18.61% 0.14% 1.89% 4.23% 2.33% Barclay High Yield Municipal Bond Index 22.76% 0.23% 2.97% - 1.11%

AVERAGE ANNUAL TOTAL RETURNS through June 30, 2010   1-Year 3-Year 5-Year 10-Year Performance Inception Date Class A Shares (NAV) 26.15% -2.27% - - -0.54% Class A Shares (POP) 20.44% -3.76% - - -1.76% Class C Return If Held 25.04% -3.15% - - -1.49% Class C Return If Redeemed 25.04% -3.15% - - -1.49% Class Y Shares (NAV) 25.77% -2.57% - - -0.82% Lipper High Yield Municipal Debt Funds Average 18.52% -0.42% 1.58% 4.11% 0.61% Barclay High Yield Municipal Bond Index 21.90% -0.12% 2.80% - 0.77%

CALENDAR YEAR RETURNS (Total Return)   YTD 2009 2008 2007 2006 Class A Shares at NAV 6.91% 34.06% -30.80% -1.98% 2.24% Class C Shares at NAV 6.51% 32.69% -31.49% -2.98% 2.06% Class Y Shares at NAV 6.95% 33.67% -31.09% -2.44% 2.24% Lipper High Yield Municipal Debt Funds Average 6.45% 31.36% -25.12% -2.82% 2.20% Barclay High Yield Municipal Bond Index 8.75% 32.74% -27.01% -2.28% 1.24%

Class A Share (POP): Reflects the deduction of maximum 4.50% sales charge.

Class C Return if Redeemed: The performance of Class C shares does not reflect the 1% front-end sales charge in effect prior to February 1, 2004. If you paid a 1% sales charge, your returns would be lower than shown above. Class C Shares held for less than one year are subject to a 1% contingent deferred sales charge (CDSC).

Class Y Return (NAV): Performance for periods prior to the inception of Y shares reflects the NAV performance of the Fund's A shares. The performance does not reflect differences in expenses, including the Rule 12b-1 fees applicable to A shares. Since fees for A shares are generally higher than those of Y shares, the performance shown for Y shares prior to their inception would have been higher. Class Y shares are not subject to sales charges and are available for limited groups of investors, including institutional investors.

NAV results represent the percent change in net asset value per share. Returns would have been lower had sales charges been reflected. The Lipper High Municipal Debt Funds Average represents the average annual returns for all high municipal debt funds for the respective time periods. The Barclays Capital High Yield Municipal Bond Index measures the performance of the high yield municipal bond market. Index returns assume reinvestment of dividends, and unlike Fund returns, do not reflect any fees or expenses. You cannot invest directly in an index. Periods less than one year are actual, not annualized.

How Tax-Free Yields Compare to Taxable Yields

Single Joint Federal Tax Bracket A tax-free yield of: 3% 4% 5% is equivalent to a taxable yield of: $7,300-$29,700 $14,600-$59,400 15.0% 3.53% 4.71% 5.88% $29,700-$71,950 $59,400-$119,450 25.0% 4.00% 5.33% 6.66% $71,950-$150,150 $119,450-$182,800 28.0% 4.16% 5.55% 6.94% $150,150-$326,450 $182,800-$326,451 33.0% 4.48% 5.97% 7.46% Over $326,450 Over $326,450 35.0% 4.62% 6.15% 7.69%

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Not FDIC insured

May lose value

No bank guarantee

Before investing, consider the product's investment objectives, risks, charges and expenses. Contact your advisor or Pioneer Investments for a prospectus containing this information. Read it carefully. To obtain a free prospectus and for information on any Pioneer fund, please download from our web site.