(CNN) -- In a major milestone for gay rights, the U.S. government on Monday expanded recognition of same-sex marriages in federal legal matters, including bankruptcies, prison visits and survivor benefits.
"It is the (Justice Department's) policy to recognize lawful same-sex marriages as broadly as possible, to ensure equal treatment for all members of society regardless of sexual orientation," Attorney General Eric Holder said in a memo to all employees.
The federal expansion includes 34 states where same-sex marriage isn't legal, but the new federal benefits being extended to those states will apply only where the U.S. government has jurisdiction.
For example, a same-sex couple legally married in Massachusetts can now have a federal bankruptcy proceeding recognized in Alabama, even though it doesn't allow same-sex marriages.
In the past, the U.S. government could challenge the couple's joint bankruptcy because Alabama doesn't recognize same-sex marriage.
Human Rights Campaign, which advocates equality for lesbian, gay, bisexual and transgender people, called it a "landmark announcement" that it "will change the lives of countless committed gay and lesbian couples for the better."
But Brian Brown, president of the National Organization for Marriage, criticized what he called the latest move by the Obama administration "to undermine the authority and sovereignty of the states to make their own determinations regulating the institution of marriage."
The move impacts how millions of Americans interact with the federal government, including bankruptcy cases, prison visitation rights, survivor benefits for police officers and firefighters killed on the job, and the legal right to refuse to testify to incriminate a spouse.
CNN's Michael Martinez and Greg Botelho contributed to this report.