Background: People with multiple sclerosis (PwMS) experienced changes in health behaviors and access to MS care due to the COVID-19 pandemic. The USA has the highest recognized number of Covid19 infections globally. The extent of the impact of COVID-19 has not been well characterized in large samples of PwMS to date. The MS patient perspective on COVID-19 would complement the physician-reported cases of MS and COVID-19 in the literature. Methods: A cross-sectional survey of adult PwMS was performed online, using the U.S.-based patient-powered iConquerMS™ platform, in April 2020. Results: There were 1,145 respondents (response rate: 20%). 1,019 had a diagnosis of MS and responded completely (average age: 54.2 years, range: 20-81; 79% female; 64% relapsing remitting, 22% secondary progressive, 12% primary progressive; 88% in the USA). 748 (73%) used a DMT in the last year, primarily higherefficacy therapies: ocrelizumab (n=238), dimethyl fumarate (n=85), fingolimod (n=80). The most frequent comorbidities were depression (41%), hypertension (26%), and asthma (12%). Women were more worried than men about COVID-19 (p=0.001); non-white-identifying PwMS believed it was a greater danger to their health than white-identifying PwMS (p=0.002). Through the continuum of symptoms to care, 61% of PwMS (n=617) reported symptoms associated with COVID-19, 39% (n=395) knew someone exposed to COVID-19, 4% (n=38) were aware of a personal COVID-19 exposure, 13% (n=128) wanted testing for COVID-19 but could not access it, and 4% (n=43) were tested. Specific to their MS care, 64% (n=650) canceled a medical visit, 22% (n=222) canceled a neurologist visit, 11% (n=112) canceled an MRI, 21% (n=212) canceled a laboratory test, and 10% (n=98) changed their DMT in some way due to COVID19 including 65 delaying at least one dose. 37% (n=382) had a telehealth visit due to COVID-19. 37% of PwMS (n=374) experienced employment changes, most commonly working from home (n=194) and having work hours reduced (n=65) while 32 lost their jobs. Of the 7 cases who tested positive for COVID-19 (<1% of participants) (5 female; age range: 29-64 years), DMTs included dimethyl fumarate (n=2), ocrelizumab (n=1), rituximab (n=1), and a clinical trial drug (n=1). Conclusions: A majority of people with MS reported interruptions to their MS care along the MS care pathway alongside limited access to COVID-19 testing. Postponements and delays in care were common with 10% of participants reporting a change in their DMT administration. Less than 1% of this self-referred convenience online cohort had a positive test for COVID-19 although more than half reported symptoms that are associated with COVID-19. Organization, 2020) By mid-April, SARS-CoV-2 was detected in 185 countries, had infected at least 19 million people worldwide, and linked to >700,000 deaths. (Johns Hopkins University, 2020) Multiple sclerosis (MS) affects more than three-quarters of a million adults in the U.S.A. People with MS (PwMS) on higher efficacy disease modifying therapies (DMTs) may be at an incr...