By Jack Hoadley, Georgetown University Health Policy Institute

The first ten years of Medicare Part D offers valuable insight into the future of the Affordable Care Act.

In July 2013, a team of Georgetown researchers, in a report funded by the Robert Wood Johnson Foundation, looked at Medicare Part D for some key lessons that the program offered to those implementing the Affordable Care Act. Part D started life during its implementation in 2005 and 2006 with low favorability ratings from the public, concerns about whether plans would choose to participate, questions about the government’s readiness to launch the program, challenges in outreach and education, and questions about whether costs would be high. Like the insurance exchanges and Medicaid expansions that are central to increased insurance coverage under the Affordable Care Act, the Part D program was essential to improved drug coverage for Medicare beneficiaries. In a new article in Health Affairs and a related report, I teamed up with Juliette Cubanski and Tricia Neuman of the Kaiser Family Foundation to review the Part D drug benefit as it reaches the end of its tenth year.

Despite the challenges the program faced at its start, Part D has grown from providing drug coverage to 22.5 million people in 2006 to 39.3 million in 2015. Today, about 88 percent of all Medicare beneficiaries have drug coverage – short of universal coverage but well above the 75 percent that preceded the arrival of Part D. Furthermore, the program’s popularity is high, and the political battles that accompanied its creation have faded. Our article on the program’s first ten years note some ongoing challenges – including how to reach those who remain without coverage and how to address the costs associated with expensive new drugs entering the market.

But Medicare Part D offers a lesson to those wondering whether broader insurance coverage under the Affordable Care Act can be sustained over a decade. It also shows that a program born in political controversy can gain bipartisan and popular support.

Editor’s Note: This is a lightly edited version of a post originally published on the Georgetown University Center for Children and Families’ Say Ahhh! Blog.