OBJECTIVES: The National Breast and Cervical Cancer Early Detection Program (NBCCEDP) is the largest organized cancer screening program for low-income, un-insured and under-insured women in the United States. The program’s effectiveness in increasing the life expectancy of participating women has never been measured. We estimated the benefits of NBCCEDP-funded cervical cancer screening (Program) in terms of life-years (LYs) saved compared to No Program and No Screening scenarios. METHODS: Based on an existing model developed by Myers et al., we constructed a cervical cancer simulation model by modifying the age and screening schedule of the cohort to reflect screening frequency for NBCCEDP participants from 1991-2007. We estimated screening habits in the absence of the program based on data from the 1990-2005 National Health Interview Survey. We performed Markov cohort analysis for each age in the 18-64 range and calculated an overall weighted average using the age distribution at first NBCCEDP Pap test for screening. Weighted averages were produced for three scenarios – women receiving testing from the NBCCEDP (the Program), women receiving testing from alternative sources in the absence of the program (No Program), and women receiving no testing at all (No Screening). We compared LY estimates for 69,100 women detected with human papillomavirus infection, low-and-high-grade squamous intraepithelial lesions or cervical cancer under the program to the counterfactual of having their disease undetected under No Program and No Screening scenarios. RESULTS: From 1991-2007, we estimate that the Program added 10,369 LYs to the total lifespan of tested women when compared to No Program, and 101,509 LYs when compared to No Screening. Furthermore, the Program prevented an estimated 325 cervical cancer deaths relative to No Program, and 3,825 relative to No Screening. CONCLUSIONS: These estimates suggest that NBCCEDP cervical cancer screening may have reduced mortality among medically underserved women in the United States.