Background/Purpose :  Biologic and non-biologic disease-modifying anti-rheumatic drugs (DMARDs) significantly reduce pain, disability and mortality in rheumatoid arthritis (RA).  We evaluated how well RA drugs are covered by Medicare Part D plans, and what copays are typically required.

Methods:   We conducted a cross-sectional analysis of all Medicare Part D stand-alone plans’ and Medicare Advantage plans’ formularies (n=2,737) in 50 states and Washington D.C. using the January 2013 Centers for Medicare and Medicaid Services (CMS) Prescription Drug Plan Formulary and Pharmacy Network Files.  Special Needs Plans (n=643) were excluded since they target subgroups of beneficiaries (e.g. institutionalized, chronic/disabling conditions, dually eligible for Medicaid) and may have specialized formularies. We used the default maintenance dose given by Epocrates©.  To calculate the national average of the percentage of plans covering a drug and account for the fact that plans cover varying geographic regions, we first calculated the percentage of plans covering a drug in each county, averaged these percentages across all counties in the state, and then averaged across all 50 states and Washington D.C.  We also examined prior authorization requirements and calculated the mean copays for each drug across all states.

Results:   All plans covered at least 1 biologic DMARD, but 91% of formularies required providers to first obtain prior authorization (PA) for covered drugs.  Across biologic DMARDs, coverage (with PA) ranged from 29% (anakinra) to 100% (adalimumab, etanercept, infliximab, rituximab; see Table).  In addition, the vast majority of plans (87%) charged a percentage co-insurance, requiring patients to pay on average 30% of drug costs.  Thus, mean copays for biological DMARDs ranged from $255 to $650 per month.  In contrast, for five non-biologic DMARDs (methotrexate, leflunomide, sulfasalazine, minocycline, hydroxychloroquine), nearly all plans provided coverage without requiring a PA.   For these non-biologic DMARDs, approximately 90% of plans charged a fixed dollar copayment (range $5 to $11 per month); see Table. 

Conclusion :  Although most health plans serving Medicare beneficiaries cover at least one biologic DMARD, nearly all require a PA and charge a percent coinsurance.  Medicare beneficiaries with RA who require biologic therapies can expect very high mean copays regardless of which Part D plan they choose, likely posing a significant financial barrier for many patients.