Cost sharing under Medicare Part D protects Medicare beneficiaries with multiple chronic conditions above the catastrophic threshold ($5000 out-of-pocket) by distributing total drug costs between Medicare (80%), prescription drug plans (15%) and beneficiaries (5%).

Current out-of-pocket copays make high-cost specialty drugs inaccessible to many beneficiaries, so the Medicare Payment Advisory Commission (MedPAC) recommends eliminating beneficiary copay and redistributing catastrophic cost sharing between prescription drug plans (80%) and Medicare (20%).

Several cost-sharing programs between federal agencies and private entities provide precedent for altering catastrophic cost sharing to reduce beneficiary burden, preserve Part D accessibility and lower drug prices.