Average out-of-pocket spending on birth control pills and intrauterine devices (IUDs) have dropped significantly since the Affordable Care Act took effect, a new study finds.

The study, published on Tuesday in Health Affairs by University of Pennsylvania researchers, compared contraceptive prescription claims from a large national insurer between the first six months of 2012, or before the “Obamacare” mandate took effect, and the first six months of 2013, or after Obamacare took effect. Comparing the two time periods, researchers found that consumers’ average out-of-pocket spending for birth control pills fell from $32.74 to $20.37, and, for IUDs, from $262.38 to $84.30.

Under the mandate, private health insurance plans are required to cover prescription contraceptives at no cost, though many women still faced costs due to insurers’ failure to comply, among other reasons.

“We estimate that the ACA is saving the average pill user $255 per year, and the average woman receiving an IUD is saving $248,” said lead author Nora V. Becker in a statement. “Spread over an estimated 6.88 million privately insured oral contraceptive users in the United States, consumer annual contribution to spending on the pill could be reduced by almost $1.5 billion annually.”

Though the report notes that it cannot definitively attribute the cost declines to Obamacare, the results are consistent with those of smaller studies that have also found sharp falls in out-of-pocket payments for contraception prescribed to privately insured women.

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