Over a thousand reproductive-aged, homeless women live in San Francisco, many of whom actively use substances. These women often exclusively contact the healthcare system through substance use treatment programs, and/or street-based homeless services. These women also frequently present to labor and delivery with scant prenatal care, or to the Women’s Options Center for later abortions or too late to receive abortion care due to the multitude of barriers impeding access to timely care. Currently, neither the Street Medicine Team nor the Opiate Treatment Outpatient Program (OTOP) at Zuckerberg San Francisco General Hospital (ZSFGH) provides family planning. Anecdotally, both programs have noted increases in unintended pregnancies and want to better understand the barriers to reproductive health services and provide appropriate interventions to improve access. With Interdisciplinary Innovation funding, we propose to develop low-barrier family planning services for homeless and substance-involved women by bringing together leaders from the Street Medicine Team, OTOP, and the Family Planning Division to: a) Assess family planning needs among homeless and substance-involved women served by ZSFGH, the Street Medicine Team and OTOP through key-informant interviews and baseline data collection, b) Develop an intervention to address this need, and apply for phase 2 Interdisciplinary Innovation funding to implement and test the intervention. If our intervention proves to be successful, we believe we can obtain sustainable funding in San Francisco, and provide a model of integrated services that can be used to provide family planning services to homeless and substance-involved women in San Francisco and other similar settings.