Most of President Biden's nominees to lead the United States' top health care agencies must be confirmed by the Senate—a process that could be delayed by an impeachment trial for former President Donald Trump. Here are the officials leading the country's federal health care agencies in the interim, as well as some officials who've assumed permanent roles.

Navigating Biden's first 100 days: What to expect from the outset of the new administration

HHS

Biden has nominated California Attorney General (AG) Xavier Becerra (D) to serve as HHS secretary, a position that must be confirmed by the Senate. Biden has tapped Norris Cochran to serve as acting HHS secretary until a permanent secretary is confirmed.

According to Inside Health Policy, Cochran has held the position of HHS' deputy assistant secretary of budget since 2012, and Cochran previously served as acting HHS secretary in January and February of 2017.

Biden also has nominated Andrea Palm to serve as HHS' deputy secretary, which requires the Senate's approval. Palm most recently held the position of secretary-designee of the Wisconsin Department of Health Services. She also had worked as a senior counselor to the HHS secretary and as HHS' chief of staff under former President Barack Obama's administration. In addition, Palm worked on the White House Domestic Policy Council during the time when the federal government began implementing the Affordable Care Act.

Biden also has appointed several civil servants at HHS to temporarily serve in leadership roles, including:

• Dan Barry to serve as acting HHS general counsel;
• Nikki Bratcher-Bowman to serve as HHS' acting assistant secretary;
• Felicia Collins to serve as HHS' acting assistant secretary for health. Biden has nominated Pennsylvania Health Secretary Rachel Levine as his permanent pick for the post;
• Robinsue Frohboese to serve as acting director of HHS' Office for Civil Rights; and
• Christi Grimm to temporarily serve as acting HHS inspector general.

In addition, Biden has appointed Sean McCluskie to serve as HHS' permanent chief of staff. McCluskie has long served as an aide to Becerra. McCluskie was Becerra's chief deputy attorney general in California and Becerra's chief of staff during Becerra's time in Congress.

Further, Biden has appointed Sarah Despres, who most recently held the position of Pew Charitable Trusts' director of government relations, as a counselor to the HHS secretary, STAT News reports.

Biden also appointed Micky Tripathi, who most recently held the position of chief alliance officer at the population health software company Arcadia, as HHS' national coordinator for health IT, which does not require the Senate's confirmation.

CMS

Biden hasn't yet announced a nominee for CMS administrator, a position that also requires Senate confirmation. However, Biden has appointed Liz Richter to serve as acting CMS administrator until a permanent administrator is confirmed. Richter's been the deputy director of CMS' Center for Medicare since 2007.

CDC

Biden appointed Rochelle Walensky, former chief of infectious diseases at Massachusetts General Hospital, to serve as the nation's CDC director. The position does not require Senate approval, so Walensky assumed the role on Wednesday.

FDA

Biden hasn't yet announced a nominee for FDA commissioner, another position that requires Senate confirmation. Until a permanent commissioner is confirmed, Janet Woodcock, the longtime director of FDA's Center for Drug Evaluation and Research, will serve as the agency's acting commissioner, Biden's administration announced this week.

While serving as acting commissioner, Woodcock also will continue serving in her role as the therapeutics lead for Operation Warp Speed, a federal initiative launched by the Trump administration to develop and distribute Covid-19 vaccines. As such, Woodcock will continue to recuse herself from making decisions on Covid-19 therapeutics at FDA, as well as from making decisions on matters relating to some specific companies involved in the Operation Warp Speed effort. "To help with the transition, I've been asked to continue some work with the therapeutics development effort. This work will involve government-sponsored research and clinical trials, and other matters that would be appropriate for an FDA employee. I will not be involved in contract discussions or similar matters with individual companies," Woodcock wrote in an email sent Wednesday to FDA staff.

Some observers have floated Woodcock, as well as former FDA Principal Deputy Commissioner Joshua Sharfstein and current FDA Principal Deputy Commissioner Amy Abernethy, as possible candidates to lead the agency permanently.

FDA's website also notes that Erika Anderson will temporarily replace Anna Abram as the agency's deputy commissioner for policy, Inside Health Policy reports. Anderson is the director of FDA's policy office and previously served as FDA's acting deputy associate commissioner for regulatory affairs in 2017.

The website also states that Mark Raza will temporarily serve as the agency's acting chief council, according to Inside Health Policy.

Other notable health care leaders

Other officials serving in notable health care roles in Biden's administration include:

• Beth Cameron, who will lead the federal Global Health Security and Biodefense group under the National Security Council;
• Bechara Choucair, who will coordinate the administration's Covid-19 vaccination efforts;
• Francis Collins, who will continue serving in his longtime roles as NIH director and does not require the Senate's approval;
• Anthony Fauci, who will continue serving in is his longtime role as director of the National Institute of Allergy and Infectious Diseases and will now also serve as the chief medical adviser for the Biden administration's Covid-19 response efforts. Fauci's positions do not require the Senate's approval;
• Elizabeth Fowler, who is temporarily serving as acting director for the Indian Health Service;
• David Kessler, a former FDA commissioner who will lead Operation Warp Speed and does not require the Senate's approval;
• Marcella Nunez-Smith, who will serve in a senior position focused on addressing health care disparities;
• Andy Slavitt, who will serve as a senior adviser for the administration's Covid-19 response; and
• Jeffrey Zients, who is serving as the Biden administration's pandemic response coordinator and does not require the Senate's approval.

Biden also has nominated Vivek Murthy, a former U.S. surgeon general under the Obama administration, to serve as surgeon general for the Biden administration. The position requires the Senate's confirmation (Knutson, Axios, 1/20; Lienhard, Inside Health Policy, 1/20/21 [subscription required]; Cohrs, STAT News, 1/21; Gooch, Becker's Hospital Review, 1/19; Stein/Ruoff, Bloomberg Law, 1/20; Florko/Facher, STAT News, 1/20; Brady/Cohen, Modern Healthcare, 1/20; Stobbe, Associated Press, 1/20; Kaplan, New York Times, 1/20; Muchmore, MedTech Dive, 1/20; Mezher, Regulatory Focus, 1/20).