Background: Financial barriers to disease modifying therapies (DMT) for multiple sclerosis (MS) have been widely reported; yet the impact of insurance restrictions on DMT choice and adherence has been studied to a lesser extent. Objectives: To evaluate insurance policy restrictions experienced by patients starting, continuing, or switching DMT for MS. Methods: A retrospective chart review of patients seen in the MS specialty clinic at Michigan Medicine between January 1st, 2020 and February 29th, 2020 was performed. Medical records were assessed for financial barriers experienced by patients with MS during initiation and transition between DMTs. Results: 460 patients were evaluated in the study of which 350 (76.1%) carried a diagnosis of MS (82% RRMS). Of these patients, 72 (20.6%) were unable to start or continue their desired DMT, as agreed upon by the provider and patient, at some point during their treatment course due to limitations related to their insurance coverage. The most common limitation was a required step therapy approach to treatment (19.8%), followed by lost or reduced insurance coverage (18.5%), and high copays (7.4%) among others. DMTs found to be difficult to access financially were glatiramer acetate (17.7%), dimethyl fumarate (17.7%), ocrelizumab (15.2%), beta-interferon-1a (12.7%), natalizumab (11.4%), teriflunomide (7.6%), rituximab (6.3%), fingolimod (6.3%), beta-interferon-1b (2.5%) and alemtuzumab (2.5%). Tecfidera and beta-interferon-1a were the DMTs most likely to be discontinued secondary to high copays. Ocrelizumab was the most likely DMT to be rejected by insurance due to a required step therapy approach to treatment, followed by dimethyl fumarate, natalizumab, fingolimod, alemtuzumab, and teriflunomide. Patients experienced most of these insurance difficulties at the initiation of treatment with DMTs (65.8%). Due to lack of insurance coverage, 46 (12.1%) patients were off DMT at some point during their MS course. Patients experiencing insurance-related restrictions were more likely to be younger during the study period (45.17yo vs 50.45yo), single (33.3% vs 19.4%) and receive medication coverage from public insurance (51.4% vs 38.8%). Conclusions: One in five patients with MS were found to experience difficulty accessing DMTs secondary to insurance restrictions, of which 63.9% were off DMT completely at some point during their MS course. Step therapy as a required approach to treatment was the most common barrier to desired DMT. Financial barriers to DMT use secondary to insurance restrictions remain a pressing concern in the care of people with MS.