Buprenorphine Coverage in the Medicare Part D Program for 2007 to 2018

Buprenorphine Coverage in the Medicare Part D Program for 2007 to 2018 Buprenorphine is critical for expanding treatment availability to individuals with an opioid use disorder (OUD) because it can be prescribed by primary care clinicians.1 However, buprenorphine is underused, and a contributing factor may be insurance company cost-control measures, such as prior authorization or step therapy. These policies, which require prescribers to obtain insurance approval prior to dispensing, may delay or disrupt treatment for patients with OUD vulnerable to relapse. For the more than 300 000 Medicare beneficiaries with OUD in 2013 (approximately 14% of 2.1 million US individuals with OUD),1,2 access to buprenorphine is important because methadone maintenance has historically not been a covered benefit.3 We evaluated trends in buprenorphine coverage in the Medicare Part D program. Methods | We analyzed Medicare Part D prescription drug plan formulary files from January 2007, 2012, and 2018 to characterize changes in coverage of buprenorphine products for OUD. Formulary files contain coverage details, including prior authorization and step therapy requirements, for both standalone and Medicare Advantage Part D plans. Using plan enrollment as weights, we estimated coverage and restrictions for each buprenorphine product using Stata version 15.1 (StataCorp). We used the Cochrane-Armitage trend test to evaluate changes in weighted proportions over time with 2-tailed P < .05 indicating statistical significance. We excluded plans with fewer than 11 enrollees because their data are suppressed. In 2016, 98% of Medicare Part D buprenorphine use was brand-name buprenorphinenaloxone sublingual films (70%), generic buprenorphinenaloxone sublingual tablets (16%), or generic buprenorphine sublingual tablets (12%).4 Therefore, we focused on brandname and generic versions of these products. We also estimated the number of plans covering any buprenorphine