A tax form distributed by the Internal Revenue Service (IRS) and used by filers seeking to claim mortgage interest credit on their tax return. In order to claim a mortgage credit, the taxpayer must first have obtained a Mortgage Credit Certificate (MCC), which are typically issued by state or local governments and agencies. The home that the Certificate is issued for must be in the same jurisdiction as the issuing agency, and must also be the tax filer's main residence. Some mortgage credit certificates, mostly those issued by the federal government or federal agencies, may not qualify for the Mortgage Interest Credit. If a mortgage is refinanced then the MCC must be reissued, and homeowners who sell their residence within nine years may have to repay some of the credit issued.