Why big businesses are still fighting for same-sex marriage

NEW YORK -- For many of the nation's largest businesses, the fight for same-sex marriage didn't end when the Supreme Court decided to overturn the Defense of Marriage Act last year.

While the federal government now recognizes same-sex marriage, individual states still get to make their own rules. And since many states continue to prohibit it, navigating through this patchwork of laws can be extremely complicated for national companies.

"There are certainly administrative issues involved in figuring out what you're doing in one state versus another -- things like payroll and trying to work with a law firm or consulting firm to help you understand the rules," says Julie Stich, research director at the International Foundation of Employee Benefit Plans.

Some company health insurance plans are governed by state law, for example, so couples living where same-sex marriage isn't recognized may not qualify for spousal benefits.

Those who do get spousal benefits have to pay state income tax on that health insurance, whereas same-sex couples living in states where their marriage is legal do not.

Other benefits, such as spousal Social Security, Medicare and medical leave, can also be subject to state laws.

As a result, a handful of Fortune 500 companies signed a legal brief this month in support of same-sex marriage in Wisconsin and Indiana -- where there are active cases challenging state bans.

" are forced to bear unnecessary costs, complexity, and risk in managing our companies, and we are hampered in our efforts to recruit and retain the most talented workforce possible, placing us at a competitive disadvantage," the brief states.

Amazon, CBS, Cisco, Marriott, Pfizer, Staples, Starbucks and Target have all signed the brief.

While most of these businesses have long shown support for same-sex marriage, this is the first time Target has publicly announced its stance. It has been criticized in the past for donating to the campaign of a Republican gubernatorial candidate in Minnesota who opposed same-sex marriage.

In a statement explaining the company's decision, Target executive vice president Jodee Kozlak said that current laws "make it difficult to attract and retain talent."