Background <p>Future telemedicine reimbursement is uncertain. Knowing which patients may be most reliant on telemedicine can help assess its value.</p> Objective <p>To identify the patient characteristics associated with using only telemedicine for primary care.</p> Design <p>Cross-sectional observational study of individuals who had multiple primary care visits in 2022.</p> Patients <p>A total of 1,151,984 adult patients with two or more primary care visits seeking care at a large integrated health system in Northern California in 2022.</p> Main Measures <p>Primary care visit modality (only telemedicine, or any in-person); associations (in adjusted percentages) between characteristics and the likelihood of accessing primary care via telemedicine only.</p> Key Results <p>Most patients (<i>n</i> = 812,581, 70.5%) used telemedicine in 2022, with 55.1% (<i>n</i> = 635,208) having both telemedicine and in-person visits, and 15.4% (<i>n</i> = 117,373) having only telemedicine visits. As adjusted percentages, 23.5% of patients 18–44&#xa0;years old (95% CI, 23.3–23.6%) used only telemedicine primary care visits, a significantly higher proportion than younger (&lt; 18—4.7%; 95% CI 4.6–4.8%) or older age groups (45–64—17.6%; 95% CI 17.5–17.8%; 65–74—13.4%; 95% CI 13.2–13.5%; 75 + —14.5%, 95% CI 14.3–14.7%). Patients who were female (16.6%, CI 16.5–16.7% vs. male 13.8%, 95% CI 13.8–13.9%), Black (17.0%, 95% CI 16.9–17.3% vs. White 15.5%, 95% CI 15.4–15.6%), living in low-SES neighborhoods (15.8%, 95% CI 15.6–15.9% vs. higher 15.4%, 95% CI 15.3–15.4%), with longer drive times to clinic (11–20&#xa0;min—15.4%, 95% CI 15.3–15.5%; 20 + min—17.7%, 95% CI 17.5–17.8%) or with a clinic parking fee (16.7%, 95% CI 16.5–17.0% vs. free 15.3%, 95% CI 15.2–15.4%) were more likely to only use telemedicine to access primary care.</p> Conclusions <p>Telemedicine may have facilitated access to primary care for patients that have barriers to in-person care.</p>