Wafa W. Tarazi, Cathy J. Bradley, Harry D. Bear, David W. Harless, Lindsay M. Sabik

States routinely may consider rollbacks of Medicaid expansions to address statewide economic conditions. To the authors' knowledge, little is known regarding the effects of public insurance contractions on health outcomes. The current study examined the effects of the 2005 Medicaid disenrollment in Tennessee on breast cancer stage at the time of diagnosis and delays in treatment among nonelderly women. The authors used Tennessee Cancer Registry data from 2002 through 2008 and estimated a difference-in-difference model comparing women diagnosed with breast cancer who lived in low-income zip codes (and therefore were more likely to be subject to disenrollment) with a similar group of women who lived in high-income zip codes before and after the 2005 Medicaid disenrollment. The study outcomes were changes in stage of disease at the time of diagnosis and delays in treatment of >60 days and >90 days. Overall, nonelderly women in Tennessee were diagnosed at later stages of disease and experienced more delays in treatment in the period after disenrollment. Disenrollment was found to be associated with a 3.3-percentage point increase in late stage of disease at the time of diagnosis (P = .024), a 1.9-percentage point decrease in having a delay of >60 days in surgery (P = .024), and a 1.4-percentage point decrease in having a delay of >90 days in treatment (P = .054) for women living in low-income zip codes compared with women residing in high-income zip codes. The results of the current study indicate that Medicaid disenrollment is associated with a later stage of disease at the time of breast cancer diagnosis, thereby providing evidence of the potential negative health impacts of Medicaid contractions. Cancer 2017. © 2017 American Cancer Society.