Investment Grade Municipal Income Fund Inc. (the “Fund”) (NYSE: PPM), a closed-end management investment company normally investing substantially all of its assets in a diversified portfolio of tax-exempt municipal obligations, with common and preferred shares outstanding, today announced that the Fund’s Board of Directors has declared a dividend from net investment income of $0.0725 per share of common stock. The dividend is payable on June 30, 2009 to common shareholders of record as of June 25, 2009. The ex-dividend date is June 23, 2009. Under normal circumstances, the Fund invests at least 80% of its net assets in investment grade municipal obligations, the income from which is exempt from regular federal income tax.

Fund Commentary for the month of May 2009 from UBS Global Asset Management (Americas) Inc. (“UBS Global AM”), the Fund’s investment advisor:

The Barclays Capital Municipal Bond Index returned 1.06% in May, outperforming US Treasuries during the month. During this time, lower-quality securities (e.g., those rated A and BBB) outperformed their higher-rated counterparts (e.g., those rated AAA and AA) while longer-maturity municipals rallied and shorter-maturity municipals weakened.

The Fund’s portfolio outperformed its benchmark in May, partially due to its yield curve positioning. As one- to five-year municipal bonds underperformed their longer-term counterparts, the Fund's relative underweight to this area helped performance. The Fund's overweight to 15- to 20-year municipal bonds also helped performance following price increases in that area of the yield curve. In addition, the Fund's limited exposure to lower-rated investment grade securities (e.g., those rated BBB) helped relative performance during the month. The Fund’s use of leverage contributed positively to results, magnifying the impact of strong performance during the month.

Disclaimers Regarding Fund Commentary - The Fund Commentary is intended to assist shareholders in understanding how the Fund performed during the month noted. Views and opinions were current as of the date of this press release. They are not guarantees of performance or investment results and should not be taken as investment advice. Investment decisions reflect a variety of factors, and the Fund and UBS Global AM reserve the right to change views about individual securities, sectors and markets at any time. As a result, the views expressed should not be relied upon as a forecast of the Fund’s future investment intent.

Characteristics as of May 31, 2009:*

* Net asset value (NAV), market price and yields will fluctuate. NAV yield is calculated by multiplying the current month’s dividend by 12 and dividing by the month-end net asset value. Market yield is calculated by multiplying the current month’s dividend by 12 and dividing by the month-end market price.

UBS Global Asset Management Closed-End Funds Desk, 888-793-8637