Because of the Defense of Marriage Law, the IRS and the rest of the United States Government does not recognize anything other than legally married opposite-sex couples.
Law allows married straight couples to file jointly and divide their income, resulting in a lower tax rate.
The IRS warns that attempts by gay and lesbian couples to file a joint return may result in fines or other penalties.
A study by the Human Rights Campaign and Urban Institute in 2004 shows that gays and lesbians pay higher taxes and get fewer benefits than straight couples.
