Lawrence B. Finer, Adam Sonfield and Rachel K. Jones of the Guttmacher Institute in New York said the study used data from an ongoing, nationally representative survey of women ages 18 to 39 and compared it to women's responses in fall 2012 -- before the contraceptive coverage requirement took effect last summer and most insured women had to pay a co-payment or co-insurance out-of-pocket for contraceptives.
The Affordable Care Act requires health insurance plans to provide family planning to couples and women with medical conditions requiring contraceptives with no out-of-pocket expense -- the cost of contraception is now included in the monthly premium.
"Our analysis provides the first quantitative evidence that the cost-sharing protection under the Affordable Care Act is indeed working as intended," Finer, director of domestic research at the Guttmacher Institute, said in a statement. "Large numbers of women who couldn't previously do so are now obtaining birth control without co-pays or deductibles, which allows them to more easily attain contraception's well-documented health, social and economic benefits."
The study, published online in the journal Contraception, also found the proportion of privately insured U.S. women who paid nothing out-of-pocket for vaginal rings increased from 23 percent to 52 percent.
Despite the changes for pill and ring users, the study found no significant change over time among privately insured injectable users or IUD users in the proportion who paid nothing.
This could indicate that some private health plans are not, as required, applying the ACA's cost-sharing protections to "the full range" of female contraceptive methods approved by the Food and Drug Administration, the researchers said.
"Unfortunately, anecdotal evidence from media reports and from health insurance companies' own publicly available documents suggests that some plans are improperly requiring patient cost-sharing in circumstances where they shouldn't," Sonfield said. "This is unacceptable, and state and federal policymakers should step up enforcement as needed."
A segment of religious employers, such as churches and other houses of worship, are exempt from this contraceptive coverage requirement.