This study is a prospective clinical trial designed to primarily test the impact of rideshare-based transportation services from a digital transportation network, Lyft, on reducing primary care clinic missed appointments--a composite outcome of no-shows and same day cancellations--for Medicaid patients. The study population consists of West Philadelphia residents who are established patients at two of the Penn Medicine Primary Care Practices within the University of Pennsylvania Health System. The study subjects are allocated into the intervention or control arm using a pseudorandomization approach - those receiving an appointment reminder on an even calendar day are in the intervention arm and odd calendar day calls are in the control arm.