The Affordable Care Act (ACA) mandated that private health plans cover contraceptives without out-of-pocket expenses for patients. Previously, long-acting reversible contraceptives (LARCs) were subject to deductibles, making them a higher-cost service for women with high-deductible health plans (HDHPs); however, the ACA mandate applied to HDHPs as well as traditional health plans. Using a national commercial claims database, we examined LARC use among continuously enrolled reproductive-age women between 2010 and 2017, comparing 9,014 women enrolled in HDHPs with 443,363 women enrolled in non-HDHPs. Using a quasi-experimental difference-in-differences analysis, we found that pre-ACA HDHP enrollees had lower LARC initiation rates than women in non-HDHPs and that rates of LARC initiation increased by 35 percent more postmandate for women in HDHPs than for women in traditional plans. These findings suggest that the ACA had a particularly important impact for women in HDHPs, who faced higher pre-ACA out-of-pocket expenses for these contraceptive methods.