Objectives: This research aims to understand undocumented immigrant participants’ experiences, program participation levels, and desired improvements in the Options program, a sliding-scale fee-for-service model for un/under-insured patients operated by New York City (NYC) Health and Hospitals (H&H). Methods: Community-engaged, mixed-methods included: focus groups (FG) (n=144), post-FG surveys, and key informant interviews (KII) (n=15) across all five NYC boroughs. All FG and KII transcripts were analyzed following grounded theory methodology. Results: Key findings include low awareness of Options; a need for greater community-based outreach efforts; prioritization of access, quality, and affordability of services; and need for activities that address concerns regarding immigrant status and fear of high bills and long-term debt. Program utilization depends on access, affordability, and patient experience factors, with particular emphasis on stigma associated with being poor and un/underinsured. Discussion: Cultural humility training, diverse staff, and language services access may be the key to increased program success.