Background: Violence in interpersonal relationships is a substantial health and social problem in the United States and is associated with a myriad of immediate and long-term physical, behavioral, and neurocognitive impairments. The present study sought to determine the incidence of U.S. emergency department (ED)-attended intimate partner violence (IPV) from 2002 to 2015 and examine the differences in payment sources before and after implementation of the Affordable Care Act. Methods: We analyzed ED visits among female patients aged 15 years or older between 2002 and 2015 from the National Hospital Ambulatory Medical Care Survey. Using International Classification of Disease, Ninth Revision, Clinical Modification, codes from patient visit records, we classified each ED visit to determine the frequency and estimate the relative proportion and national frequency of IPV visits. We explored bivariate and multivariate associations between IPVrelated injuries with age, race, ethnicity, method of payment, and region, noting changes over time. Results: Between 2002 and 2015, female patients visited EDs an estimated 2,576,417 times for IPV-related events, and the proportion of ED visits for IPV increased during that time period. The percentage of ED visits for IPV-related events did not differ significantly by region, race, or ethnicity. Compared with women 25-44 years of age, women aged 65 to 74 (odds ratio, 0.15; 95% confidence interval, 0.05-0.43; p < .001) and 75 years and older (odds ratio, 0.20; 95% confidence interval, 0.08-0.53; p ¼ .001) were less likely to visit an ED for IPV. Women were more likely to pay for IPV-related services out-of-pocket (i.e., self-pay) (odds ratio, 1.85; 95% confidence interval, 1.24-277; p ¼ .003) before the enactment of the Affordable Care Act. Conclusions: The increase in the percentage of IPV-related ED claims paid by private insurance suggests that the Affordable Care Act may have increased women's willingness and ability to seek medical attention for IPV-related injuries and disclose IPV as the source of injuries.