The National Breast and Cervical Cancer Early Detection Program is a multifaceted, federal program that provides breast and cervical cancer screening and diagnostic services to low-income women, but does not cover the costs of treatment. This study used a fixed-effects, longitudinal time-series research design (from 1995 to 2005) to evaluate the impact of a Medicaid expansion aimed at covering treatment for program clients, enacted via the Breast and Cervical Cancer Prevention and Treatment Act of 2000. In summary, the Treatment Act of 2000 had some positive impacts, including a 12.8% decrease in the average number of days to definitive cervical diagnosis for White women. Nonetheless, the Treatment Act also had some negative impacts on the timing of diagnosis and treatment services, including a significant increase in the average time between a diagnosis of cervical dysplasia or cancer and the initiation of treatment for Black and Hispanic women (7-15 days across age groups). The Treatment Act was also associated with a 9% decrease in the probability that Black women would initiate treatment within 60 days of a cervical diagnosis (-.094; 95% confidence interval [CI] -.178 to -.01). As such, although the Treatment Act had no impact on the proportion of clients who initiated breast cancer treatment within 60 days, it reduced the probability that Black women initiated cervical treatment within an accepted benchmark for timely care.