To amend the Internal Revenue Code of 1986 to modify the limitations on the deduction of interest by financial institutions which hold tax-exempt bonds.

Municipal Bond Market Support Act of 2008 - Amends Internal Revenue Code provisions relating to the small issuer exemption from interest expense allocation rules for financial institutions to: (1) increase from $10 to $30 million the annual limit on small issuers of tax-exempt municipal bonds; (2) allow an inflation adjustment to such increased limit amount after 2009; (3) repeal aggregation...