Congressional health committee leaders

Chair: Kevin Brady (R-Texas) Brady would be a leader in GOP efforts to revamp Medicare as a premium-support system. He has said, however, that he intends for the process to be gradual, with early Medicare reforms targeting post-acute care.

Ranking: Richard Neal (D-Mass.) Neal signaled he will pressure Republicans to work with Democrats to improve the ACA and called it “shortsighted to start anew” with repeal. He has supported bundled payments in Medicare and has used tax legislation to support rural healthcare providers.

Health subcommittee

Chair: Pat Tiberi (R-Ohio) Tiberi has resisted site-neutral Medicare payments and has promoted Medicare Advantage plans. He will be a key figure if the GOP pushes a premium-support model for Medicare.

Ranking: Sander Levin (D-Mich.) Levin helped pass the ACA in 2010 and will work aggressively to protect that law and resist GOP efforts to alter Medicare and Medicaid.

Chair: Greg Walden (R-Ore.) He is considered one of the leaders in the House's fight to unravel the ACA. As a congressman representing rural communities in Oregon, he has backed legislation aimed at improving mental health and substance abuse services.

Ranking: Frank Pallone (D-N.J.) He led Democrats' efforts to bolster National Institutes of Health funding in the 21st Century Cures Act and then was a chief backer of the sweeping legislation.

Health subcommittee

Chair: Michael Burgess (R-Texas) Burgess is a physician and strongly supported MACRA to replace Medicare's sustainable growth-rate formula for paying physicians. He's now pushing for more flexibility for physicians to comply with the new law.

Ranking: Gene Green (D-Texas) Green has described his job as fighting “on the front lines against the Trump Administration.”

Chair: Rodney Frelinghuysen (R-N.J.) He has called for keeping some popular aspects of the ACA, including requiring insurance companies to cover people with pre-existing conditions and allowing young adults to stay on their parents' insurance.

Ranking: Nita Lowey (D-N.Y.) She is expected to fight attempts to defund Planned Parenthood and work to protect insurance coverage of women's health services

Subcommittee on Labor, Health and Human Services, Education and Related Agencies

Chair: Tom Cole (R-Okla.) He says healthcare costs can be cut with tort reform and cracking down on waste, fraud and abuse, and he's wary of regulations that may encroach on personal health choices.

Ranking: Rosa DeLauro (D-Conn.) A cancer survivor, DeLauro has championed funding boosts for the NIH, FDA and CDC. She's an aggressive defender of the ACA.

Chair: Diane Black (R-Tenn.) Black, a registered nurse, has supported legislation aimed at improving chronic care management and expanding telehealth services.

Ranking: John Yarmuth (D-Ky.) He may be a key voice in protecting Medicaid coverage levels as he argues against new Kentucky Gov. Matt Bevin's attempts to reshape Kentucky's program with provisions such as a requirement that beneficiaries be employed or looking for work

Chair: Orrin Hatch (R-Utah) Hatch sponsored an ACA replacement with provisions that include allowing insurers to sell plans across state lines, Medicaid block grants and capping the tax exclusion on employer-based plans. He also has backed efforts to retool the Stark Law's restrictions against physician self-referral.

Ranking: Ron Wyden (D-Ore.) Wyden is behind an ACA provision that allows states to get waivers from many of the law's requirements if they can provide coverage that's at least as comprehensive and affordable. He may be an ally if Republicans pursue state flexibility as an alternative to full repeal.

Health subcommittee

Chair: Patrick Toomey (R-Pa.) Toomey is a staunch ACA critic and opponent of abortion rights.

Ranking: Debbie Stabenow (D-Mich.) Stabenow has fought for funding to address lead-contaminated water in the city of Flint, Mich., and has called for more mental health funding for community centers.

Chair: Lamar Alexander (R-Tenn.) He is one of a few GOP senators expressing doubts about moving too quickly to kill the ACA. His willingness to work across party lines could make him an important figure in the repeal effort.

Ranking: Patty Murray (D-Wash.) Democrats will count on Murray to argue forcefully against rolling back coverage for reproductive health and push legislation to improve mental health services.

Chair: Thad Cochran (R-Miss.) He has supported medical research funding and efforts to fight public health threats like Zika and Ebola.

Ranking: Barbara Mikulski (D-Md.) She has been a champion of Maryland's unique all-payer system that could be a model for state-based health reforms

Subcommittee on Labor, Health and Human Services, Education and Related Agencies

Chair: Roy Blunt (R-Mo.) Blunt has been a key figure in pushing mental health funding and reform and has advocated for community health centers.

Ranking: Patty Murray (D-Wash.) (See Senate HELP above)

Chair: Susan Collins (R-Maine) Considered one of the most moderate Republicans in Congress, she could be one of a handful of GOP senators who make it difficult for the chamber to repeal and replace the ACA and make dramatic changes to Medicare and Medicaid.

Ranking: Bob Casey (D-Pa.) He has emphasized protecting Medicare beneficiaries from higher premiums and deductibles and easing the enrollment process.