U.S. District Judge Audrey Fleissig in St. Louis based her ruling on a provision of the U.S. Constitution that says federal laws take precedence over contradictory state laws.
Planned Parenthood of Kansas and Mid-Missouri welcomed the ruling in a news release.
"This is a victory for Missouri women and their families," said Peter Brownlie, president and chief executive officer of Planned Parenthood of Kansas and Mid-Missouri. "This ruling ensures that all Missouri women -- no matter who their boss is -- have access to basic preventive health care without a co-pay, including birth control.
"This is a decision for women, not their bosses to make. Bosses don't have to take birth control, and they don't have to pay for it -- and thanks to the federal court ruling, they can't decide whether the women who work for them are able to have birth control covered by their insurance like any other prescription."
Planned Parenthood estimated approximately 940,000 Missouri women will benefit from the Affordable Care Act's provision allowing access to free birth control, MissouriNet reported.