Accounting and advisory firm Marcum LLP has introduced an interactive online map that tracks the status of same-sex marriage in each of the 50 U.S. states and how such unions are treated for tax purposes.

The map was created as a tool for clients of Marcum’s national Lesbian, Gay, Bisexual, Transgender (LGBT) & Non-Traditional Family Practice group. It allows users to view the status of same-sex marriage unions in individual states by moving their computer cursors over them on the map. A pop-up chart for the highlighted state reveals various information, including whether same-sex marriage or rights similar to marriage are recognized in that state, and the effective date the applicable law was enacted or repealed. 

The chart also notes whether it is a community property state and if protective tax refund claims or amended allocated tax returns should be filed. The map can be accessed at http://www.marcumllp.com/LGBT-Unions.

As of Jan. 1, 2013, nine states, including Connecticut, Iowa, Maine, Maryland, Massachusetts, New Hampshire, New York, Vermont and Washington, as well as the District of Columbia, have legalized same-sex marriage. In addition, Rhode Island recognizes same-sex marriages performed in other jurisdictions, while California, which briefly granted same-sex marriages in 2008, now recognizes them on a conditional basis.

“The Marcum Same-Sex Marriage Map gives same-sex couples and non-traditional families an easy way to check fundamental facts relevant to taxpayer status in their home state or others,” said Nanette Lee Miller, national leader of Marcum’s LGBT practice group and partner-in-charge of assurance services for the firm’s California offices, in a statement. “This will be an especially useful tool once the U.S. Supreme Court rules on the definition of marriage as contained in the Defense of Marriage Act, which is expected to have broad-ranging implications for the way same-sex couples and non-traditional families are taxed at the federal and state levels.”

Marcum’s professionals have more than 20 years of experience in dealing with the complex tax and financial rules faced by LGBT couples and families, state-by-state and around the country.

“In states permitting or recognizing same-sex unions, taxpayers must be vigilant and proactive in order to make sure they are getting full benefit from the equitable tax treatment that is available to them,” said Janis Cowhey McDonagh, a partner in the firm’s New York City office and a member of its Trusts and Estates Practice group, who frequently lectures on LGBT estate and income tax issues and is the author of Top 10 Estate Planning Tips for LGBT & Non-Traditional Families. “It is critical that married same-sex couples file protective claims now to ensure that they have access to any retroactive refunds they may be due pending the Supreme Court decision,  before the statute of limitations expires. The ruling may also allow same-sex married couples to benefit from tax-advantaged estate planning.”