With More Subsidy Upfront, Part D Average Bid Will Rise 180% in 2025

Following an unprecedented year-over-year increase in 2024 stemming from provisions in the Inflation Reduction Act (IRA), the Medicare Part D national average monthly bid amount (NAMBA) is projected to increase by $115, or nearly 180%, to $179.45 in 2025. That number reflects big changes to the Part D benefit, such as the government passing more risk to Prescription Drug Plan (PDP) and Medicare Advantage Prescription Drug (MA-PD) sponsors, but it doesn’t mean the full bump in estimated costs will be passed onto consumers. At the same time, the federal government on July 29 unveiled a new demonstration opportunity for PDPs intended to provide additional premium stability across the Part D market.

The NAMBA — an enrollment-weighted average of the estimated cost to Part D plan sponsors of providing the basic benefit package — was always expected to increase because of benefit changes taking effect next year; it was just a question of how much higher it would be.