One of the Medicare and Medicaid programs’ most vocal champions, Rep. Henry A. Waxman, a California Democrat, recently announced plans to retire from the U.S. House of Representatives at the end of this year – his 40th on Capitol Hill.

Waxman has been a relentless leader in nearly all areas of health policy, including the Food and Drug Administration, Medicare and Medicaid, tobacco regulations and HIV/AIDS.

Despite being a liberal Democrat, he has been able to work collaboratively with Republicans and pass major pieces of legislation throughout his career on the hill. Four decades of health care expertise and Congressional institutional knowledge also departs when he retires

Waxman has left his mark on some of the most important pieces of health legislation of the past few decades.

As the former chairman of the Energy and Commerce Committee chairman he helped to craft the 2010 Affordable Care Act. He co-authored the Hatch-Waxman Act, which made it easier for generic drugs to enter the market and compete with brand-name pharmaceuticals. Waxman wrote the Orphan Drug Act, which gave market and tax incentives to drug companies to develop drugs for small patient populations. He also worked to create the Children’s Health Insurance Program and to expand Medicaid.

Waxman was instrumental in crafting laws to improve the nation’s air and water supply, reduce greenhouse gas emissions and remove lead in paint, drinking water and children's toys. He brought tobacco company executives to testify before Congress in the 1990s. He pushed for and won tougher health warnings on cigarette packages. He also led the 2005 hearings into steroid use in major league baseball.

At age 74, Waxman says he is not leaving out of frustration with Congress; instead, he says he wants to explore other avenues for public service and feels that it is time for someone younger to leave their mark on the nation.