Background: Research into the impact of COVID-19 on people with MS is ongoing. Objectives: To gain an understanding of COVID-19 practices and experiences among patients with multiple sclerosis (MS) enrolled in MS LifeLines, a disease-modifying therapy patient-support program. Methods: Enrollees from MS LifeLines were invited to participate in an internet-based survey. Participants were included if they self-reported physician-diagnosed relapsing MS, initiated cladribine tablets or were currently being treated with interferon beta-1a (scIFN?1a), and aged ?18 years. Information collected included demographics, clinical characteristics, MS treatment/disease history, and COVID-19 understanding, preventive measures, exposure, and vaccination experiences. Findings were analyzed descriptively. Results: Among 1095 patients completing the survey from May 12-July 2, 2021 (616 cladribine tablets, 479 scIFN?1a), mean (SD) age was 50 (11.9), 77.9% female, 76.9% non-Hispanic White/9.4% non-Hispanic Black/6.7% Hispanic; and mean (SD) Charlson Comorbidity Index 0.41 (0.89). Half (51.6%) had changed from in-person visits to telephone/video, 44.7% discussed COVID-19 concerns with their physician, and 26.4% discussed MS medication concerns. Patients described their understanding of the risk of developing complications with COVID-19 as very well (48.5%) or fairly well (26.6%). COVID?19 preventive measures were widely practiced (% responding always: mask wearing, 79.7%; monitoring symptoms, 68.0%; hand washing, 66.9%; 6-foot social distancing, 56.5%; staying home, 51.5%; cleaning/disinfecting surfaces, 35.5%). For the total cohort, 7.8% received a positive COVID-19 test, 54.8% had a COVID-19 test, 16.3% had COVID-19 symptoms, and 30.9% had close contact with someone with COVID-19. Most (74.6%) were vaccinated, 8.3% were planning to get vaccinated, 12.1% were not planning to get vaccinated, and 5.0% were unsure. Similarly, 76.3% discussed COVID-19 vaccination with their physician, 8.2% were planning to discuss vaccination with their physician, 11.1% were not planning to discuss vaccination with their physician, and 4.4% were unsure. Conclusions: The findings provide insight into COVID-19 understanding, preventive measures, exposure, and vaccination experiences of patients with MS.