Abstract: From 2020 to 2023, the Department of Veterans Affairs (VA) conducted a national pilot of a rideshare program to support homeless patients' transportation needs to obtain critical resources and attend medical appointments. This study linked Lyft rideshare data in 2022 to VA administrative data to examine characteristics and changes in service use among VA homeless service users. The results showed that VA homeless service users who used the VA Rideshare program were more likely to have psychiatric diagnoses and urgent care visits than those who did not use the program. When we controlled for past VA service use, use of the VA Rideshare program was associated with greater use of VA outpatient and inpatient services and fewer no-show medical appointments six months after the veterans' index date. VA Rideshare users had three to eight more program visits over the course of six months than non-Rideshare users. These findings indicate benefits associated with providing transportation assistance to vulnerable patients in a nationwide health system.