Importance: The closure of the Medicare Part D coverage gap from 2010 to 2019 was intended to help decrease out-of-pocket costs for beneficiaries, especially those taking high-cost drugs. However, yearly increases in list prices and the introduction of newer and more expensive drugs may have limited savings for beneficiaries.
Objective: To assess the association of closure in the Medicare Part D coverage gap with projected annual out-of-pocket costs from 2010 through 2019 for rheumatoid arthritis (RA) biologics.
Design, setting, and participants: This cross-sectional analysis used data from the Medicare Formulary and Pricing Files for the first quarter (January 1 to March 31) in each calendar year from 2010 to 2019 for 17 RA biologic drug and strength combinations.
Exposures: Medicare Part D plan design and drug price by year.
Main outcomes and measures: Expected annual out-of-pocket costs for 1 year of treatment.
Results: Among the 17 drug and strength combinations assessed, list prices increased each year for every product, with a mean increase of 160% for the 6 drugs available during the entire study period. For the 6 products available during the entire study period, projected mean (SD) annual out-of-pocket costs were 34% (2%) lower in 2011 than in 2010 ($6108 in 2010 to $4026 in 2011) but only 21% (8%) lower in 2019 ($4801) because of yearly increases in list price. All 4 products with higher out-of-pocket costs in 2019 than in the first year available entered the market between 2011 and 2015. For all products studied, the percentage of money spent in the catastrophic phase increased each year and was a mean (SD) of 22% (14%) higher in 2019 than in 2010 or the year first available.
Conclusions and relevance: Although beneficiaries experienced large reductions in out-of-pocket spending from 2010 to 2011, more than half of those savings were lost by 2019 because of annual increases in list prices, even as the coverage gap continued to close in subsequent years.