e18685 Background: Breast cancer mortality is 41% higher for Black women than for Non-Hispanic White women. This difference is partly due to disparities in access to high quality screening and timeliness of follow-up of abnormal mammographic findings. This study aimed to identify barriers to mammographic screening and follow-up among a medically underserved, low-income, predominantly Black community in West Philadelphia during a free community screening initiative. Methods: Free breast cancer screening was provided for eligible, average-risk members of the community via a mobile mammography unit for two weeks in June 2022. This initiative was situated as part of a larger, multidisciplinary cancer screening fair that was organized by a collaborative of faculty and staff from our academic hospital and community volunteers. Women attending the fair were offered surveys on access to breast cancer screening. For those who subsequently underwent mobile mammographic screening, health insurance and time to follow-up testing, if needed, were collected from the electronic medical record. Results: 233 women completed surveys (mean age 54±13 years). Among respondents, 93% identified as Black, and 82% reported having a PCP. Of those with a PCP, 55% reported having previously had a breast physical exam, and 56% had been counseled on their personal breast cancer risk. 49% were advised to begin screening by age 40, while the remainder were either counseled to begin at an older age, or were not advised on when to initiate screening. 74% of the cohort endorsed at least one barrier to screening mammography. The most frequently cited barrier was cost and/or lack of insurance coverage (30%), followed by time limitations due to work schedule (21%), fear/anxiety of screening results (20%), fear/anxiety of pain or discomfort (20%), and difficulties with scheduling (19%). Of 181 women who underwent mobile screening mammography, 24 (13%) received a BIRADS 0 assessment, and 11 (6%) went on to undergo breast biopsy. There was a trend toward longer delays between screening and biopsy for women who did not have a PCP (median 45 days, IQR 31–52) compared to those who did (median 24 days, IQR 16–29) (p = 0.072). Three patients who received BIRADS 0 assessments have not yet followed up, all of whom lack health insurance. Conclusions: In this cohort of women from a predominantly Black, medically-underserved community, significant logistical barriers to mammography and follow-up were identified both by self-report and by documented delays in care. Free mobile mammography initiatives that bring medical professionals into the community can help address these barriers, while also providing education and personalized risk assessment. Importantly, sustained engagement is necessary to ensure appropriate follow-up for women found to have additional care needs after screening and is area of future growth for our program.