The policy change was announced on the plan's website, dated Oct. 8.
The Missouri Consolidated Health Care Plan said they will begin to accept enrollment applications from same-sex couples with a valid marriage license from another state. The government health care plan covers nearly 100,000 government employees and spouses, along with other government workers, according to their website.
Mia Platz, communication and publication manager for the Missouri Consolidated Health Care Plan, said same-sex spouses will be able to enroll in the program once the details are worked out.
"We're going to have a special enrollment period for folks who, if that situation does apply to them, they will have a time period where they can enroll, their spouses as well as their spouse's dependents," Platz said. "We are still finalizing the details on that, that all of our members will be receiving more information about that here very shortly."
The plan's change follows a decision from Jackson County Circuit Judge J. Dale Youngs, a Gov. Jay Nixon appointee, to require the state of Missouri to recognize same-sex marriages from other states.
"All they do is treat one segment of the population - gay men and lesbians - differently than their same-sex counterparts, for no logical reason," Youngs wrote in his opinion.
Missouri Attorney General Chris Koster announced he would not appeal the decision.
"Our national government is founded upon principles of federalism - a system that empowers Missouri to set policy for itself, but also obligates us to honor contracts entered into in other states," Koster wrote in his statement.
Koster made the announcement on the same day that the U.S. Supreme Court decided not to hear appeals of several rulings striking down bans on gay marriage in various states. Missouri was not one of the states covered by those rulings.
Koster wrote that Missouri's future involves everybody, "...we should not demand that certain individuals surrender their marriage licenses in order to live and work among us," Koster wrote.
Koster's decision came under immediate attack from Republican legislative leaders.
Senate Leader Tom Dempsey, R-St. Charles, was quoted in a news release saying Koster's decision not to appeal the decision is a contradiction to a statewide vote on Missouri's constitution.
"This ruling by one local judge stands in direct contradiction to our constitution which was approved by a statewide vote," Dempsey said in a news release. "The Attorney General is a clever lawyer and knows full-well that the 'full faith and credit clause' he cites as a justification not to perform the clear duty of his office does not apply when the law of one state flatly contradicts the public policy of a sister state. He is simply hiding behind thin legal justifications as he seeks to undermine the will of Missouri voters."
House Speaker Tim Jones released a statement saying Koster must defend the Missouri Constitution or find someone to replace him who can.
"Chris Koster has a duty to defend our state's constitution, whether he personally agrees with it or not," Jones wrote in the statement. "His job is to uphold and defend our constitution, not to make policy. He cannot just abandon his duties when they are politically inconvenient, and I think it is disgraceful that he is attempting to do so," Jones wrote in his statement.
"Today, I have personally called upon Attorney General Chris Koster an asked him, in writing, to defend our state's constitution or to appoint someone in his place who is capable and able of doing so."