Background: Because cost may be a barrier to receiving mammography screening, cost sharing for ''innetwork'' screening mammograms was eliminated in many insurance plans with implementation of the Affordable Care Act. We examined prevalence of out-of-pocket payments for screening mammography after elimination in many plans. Materials and Methods: Using 2015 National Health Interview Survey data, we examined whether women aged 50-74 years who had screening mammography within the previous year (n = 3,278) reported paying any cost for mammograms. Logistic regression models stratified by age (50-64 and 65-74 years) examined out-ofpocket payment by demographics and insurance (ages 50-64 years: private, Medicaid, other, and uninsured; ages 65-74 years: private-Medicare, Medicare+Medicaid, Medicare Advantage, Medicare only, and other). Results: Of women aged 50-64 years, 23.5% reported payment, including 39.1% of uninsured women. Compared with that of privately insured women, payment was less likely for women with Medicaid (adjusted OR 0.17 [95% CI 0.07-0.41]) or other insurance (0.49 [0.25-0.96]) and more likely for uninsured women (1.99 [0.99-4.02]) (p < 0.001 across groups). For women aged 65-74 years, 11.9% reported payment, including 22.5% of Medicare-only beneficiaries. Compared with private-Medicare beneficiaries, payment was less likely for Medicare+Medicaid beneficiaries (adjusted OR 0.21 [95% CI 0.06-0.73]) and more likely for Medicareonly beneficiaries (1.83 [1.01-3.32]) (p = 0.005 across groups). Conclusions: Although most women reported no payment for their most recent screening mammogram in 2015, some payment was reported by >20% of women aged 50-64 years or aged 65-74 years with Medicare only, and by almost 40% of uninsured women aged 50-64 years. Efforts are needed to understand why many women in some groups report paying out of pocket for mammograms and whether this impacts screening use.