If the top individual tax rate were lowered to 25% from the current 39.6%, as favored by Republicans, and the alternative minimum tax were repealed, it would cost $3.77 trillion over 10 years, according to a Joint Committee on Taxation report released Wednesday.

The JCT prepared estimates of a proposal that would repeal the individual AMT, reduce individual income rates to 25%, and reduce the corporate tax rate to 25%, in response to a request from the House Ways and Means Committee's ranking minority member Rep. Sandy Levin, D-Mich.

It would cost an estimated $5 trillion if both the individual and corporate tax rates were dropped to 25%, JCT said.

The estimates were sent to Levin in a July 18 letter that was not publicly released until Wednesday.

The JCT estimated that the proposal would be enacted on Oct. 1, 2013 and would be effective for taxable years beginning after Dec. 31, 2013.

For fiscal years 2013 through 2017, all municipal bond related tax expenditures totaled $267.3 billion over five years, the JCT report said. Specifically, public purpose state and local government bonds would be $191.3 billion, other miscellaneous qualified state and local bonds would be $38.4 billion, private-activity bonds for nonprofit and qualified public educational facilities totaled $18.2 billion, and PABs for nonprofit hospitals was $12.4 billion.

Subscribe Now

Independent and authoritative analysis and perspective for the bond buying industry.

14-Day Free Trial

No credit card required. Complete access to articles, breaking news and industry data.