Pioneer Investments Announces Changes to Investment Policies of Pioneer Municipal High Income Trust (MHI)

  
    
  
  
    
      Pioneer Investments announced today that the Board of Trustees of 
      Pioneer Municipal High Income Trust (NYSE: MHI) approved changes to the 
      fund’s investment policies to increase the fund’s 
      ability to invest in securities that are rated below investment grade. 
      The new policy is intended to enhance the fund’s 
      investment flexibility and income potential, consistent with the fund’s 
      investment objectives.
    
    
      Under the new policy, up to 60% of the fund’s 
      portfolio of municipal securities may be rated below investment grade at 
      the time of acquisition (that is, “Ba” 
      or lower by Moody’s Investors Service, Inc. (“Moody’s”) 
      or “BB” or lower 
      by Standard & Poor’s Ratings Group (“S&P”)). 
      This percentage previously was no more than 50%. In addition, the fund’s 
      policy of maintaining a dollar-weighted average credit rating of at 
      least investment grade has been eliminated to allow for utilization of 
      the new 60% policy. Consistent with the new 60% policy, at least 40% of 
      the fund’s portfolio of municipal securities 
      will be rated investment grade at the time of acquisition (that is, at 
      least “Baa” by 
      Moody’s or “BBB” 
      by S&P) or, if unrated, determined by the fund’s 
      investment adviser to be of comparable credit quality.
    
    
      Pioneer Investments believes that a higher exposure to below investment 
      grade municipal securities, upon careful consideration of the risks that 
      these securities may present, may enable the fund to capitalize on the 
      yield advantage of lower rated municipal securities over higher rated 
      securities in current and future environments and thereby enhance the 
      fund’s income potential and overall 
      performance. This change also may align the fund more closely with its 
      peers from an income perspective over time.
    
    
      The fund is a closed-end investment company and trades on the New York 
      Stock Exchange (NYSE) under the symbol MHI. Pioneer Investment 
      Management, Inc. is the fund’s investment 
      adviser.
    
    
      Keep in mind, dividends are not guaranteed. Closed end funds, unlike 
      open-end funds, are not continuously offered. There is a one-time public 
      offering and once issued, shares of closed-end funds are bought and sold 
      in the open market through a stock exchange and frequently trade at 
      prices lower than their net asset values. Net Asset Value (NAV) is total 
      assets less total liabilities divided by the number of common shares 
      outstanding. For performance data on Pioneer's closed-end funds, please 
      call 800-225-6292 or visit our closed-end 
      pricing page.
    
    
      Municipal securities of below investment grade quality are regarded 
      as having predominantly speculative characteristics with respect to the 
      issuer's capacity to pay interest and repay principal, and are commonly 
      referred to as "junk bonds" or "high yield securities." 
      The fund may invest in municipal securities the interest income on 
      which is a preference item for purposes of the alternative minimum tax.
    
    
      ©Pioneer Investment Management, Inc. Member 
      of the UniCredito Italiano Banking Group, Register of Banking Groups