To compare utilization trends of multiple sclerosis (MS) disease-modifying therapies (DMT) between the Department of Veterans Affairs (VA) and US Medicare healthcare programs. 

Total counts and proportions of patients with MS using specific DMT in the VA and Medicare administrative health claims datasets were used to estimate yearly changes in utilization from 2012 to 2021. Proportionate use of generics was evaluated for dimethyl fumarate and fingolimod. Trends in utilization patterns were compared qualitatively between systems. 

In 2021, 7,836 Veterans and 88,396 Medicare beneficiaries received a DMT. From 2012 to 2021, the proportion of patients using lower-efficacy DMT (interferons, glatiramer) declined more in VA (90% to 32%, 58% decline) than Medicare (81% to 38%, 43% decline) populations. Oral DMT use increased to a similar degree with 39% of patients in both systems receiving oral therapy by 2021. Veterans had higher fumarate use (mostly dimethyl fumarate), while Medicare beneficiaries had higher use of teriflunomide and sphingosine 1-phosphate inhibitors. Proportion of B cell depleting DMT (ocrelizumab, ofatumumab, rituximab) use was 5%-6% higher in the VA, which also utilized more rituximab than Medicare. When available, generic DMT are nearly exclusively used in the VA. In contrast, in 2021 utilization of generic glatiramer (available in 2015) was 51% and generic dimethyl fumarate (available in 2020) was 47% among Medicare beneficiaries. 

While overall DMT utilization trends in both systems were generally similar, VA is distinct in its uniform use of generic DMTs. VA utilization management strategies may also influence use of high-efficacy B cell depleting therapies.