President Barack Obama has begun to reshape his Cabinet at the start of his second term, elevating four of his long-time advisers to key positions.
More changes are still to come, as officials step down after long tenures through stressful periods at top jobs.
Obama has faced criticism for his choices, in part because of past policy decisions and statements some have made, but also because he has so far named four white men to a Cabinet once lauded for its diversity.
Following is a list of nominations thus far - all of which require Senate confirmation - along with some Cabinet members who the White House has confirmed are staying on, and some important positions that are vacant or may soon become vacant.
* State - John Kerry, the unsuccessful 2004 Democratic presidential nominee and chairman of the powerful Senate Foreign Relations Committee, has been nominated to replace Hillary Clinton.
* Treasury - Jack Lew, Obama's chief of staff and a two-time White House budget director, would take the top economic job at a time when the White House faces another round of tough negotiations on deficit issues with Congress. He would replace Timothy Geithner.
* Defense - Chuck Hagel is a former Republican senator and a decorated war veteran who fought in Vietnam. Hagel faces a tough confirmation battle because of past controversial comments about Israel and gays. Defense Secretary Leon Panetta is retiring.
* CIA director - John Brennan was Obama's counterterrorism adviser, and has worked for the CIA as officer, analyst and administrator. He would replace David Petraeus, who resigned in November over an extramarital affair.
STAYING PUT, FOR NOW
* Justice - Attorney General Eric Holder, who is part of an Obama task force looking at how to reduce gun violence, will stay on. There had been widespread speculation he would not serve more than four years, a rare long term for an attorney general.
* Homeland Security - Secretary Janet Napolitano had been expected to take over the Justice file if Holder left. Now that the White House has said Holder will stay, Napolitano is expected to remain in her current job.
* Agriculture - Secretary Tom Vilsack, who has spearheaded talks with Congress about cuts to farm subsidies, will stay on for Obama's second term.
* Health and Human Services - Secretary Kathleen Sebelius will remain in her job.
* Veterans Affairs - Secretary Eric Shinseki, a former U.S. Army chief of staff, will stay on.
* Education - Secretary Arne Duncan will stay in his job.
COMMERCE - VACANT
Secretary John Bryson resigned in June for health reasons. Rebecca Blank, an economist, has been acting secretary since then.
- Steve Case - co-founder of America Online, is part of Obama's Council on Jobs and Competitiveness, an advisory group of corporate executives, labor leaders and academics.
- Daniel Doctoroff - chief executive of the financial news service Bloomberg and a former deputy mayor of New York City under Mayor Michael Bloomberg, founder of the eponymous company.
- Ronald Kirk - the U.S. trade representative. He has made clear he wants to return to his hometown of Dallas after four years of traveling the globe. But he might be tempted to stay, if Obama were to offer him the Commerce Department post and four more years in the Cabinet.
- Jeff Zients - acting director of Obama's budget office and a former management consultant who could play a role should the president seek to reorganize the Commerce Department and the Office of the U.S. Trade Representative into a consolidated business-oriented government agency.
LABOR - VACANT
Secretary Hilda Solis, the first Latina to head a major U.S. federal agency, announced plans to resign. It is not clear who is in the running to replace her.
ENERGY - COULD SOON BE VACANT
Speculation is rampant that Steven Chu will soon resign after a tumultuous time at the helm of the Energy Department. Chu, a Nobel Prize-winning physicist, took the fall for the administration over a failed loan to solar-panel maker Solyndra, which Republicans trumpeted as a symbol of government waste and mismanagement.
- Christine Gregoire - a former Washington state governor, Gregoire has been mentioned as a potential candidate for three energy-related positions in Obama's Cabinet: the Environmental Protection Agency, Interior and Energy.
- Byron Dorgan - former North Dakota senator who was a member of the Senate Energy Committee and focuses on energy issues at the Bipartisan Policy Center, a Washington think tank.
- Bill Ritter - former Colorado governor who helped reform regulations on oil and gas in his state, and now advocates for responsible oil and gas drilling from a post at Colorado State University.
WHITE HOUSE CHIEF OF STAFF - VACANT
When Lew departs for the Treasury Department, Obama will need to name a new chief of staff. Possible replacements:
- Denis McDonough - Obama's deputy national security adviser, is thought to be the leading candidate.
- Ron Klain - former chief of staff to both Vice President Joe Biden and the previous Democratic vice president, Al Gore. He left the administration in 2011 to work for former AOL chairman Steve Case.
- Valerie Jarrett - a longtime Obama confidante, is a senior adviser to the president. She has known Obama since she hired his then-fiancee, Michelle Robinson, for an opening in the office of Chicago Mayor Richard Daley in 1991.
ENVIRONMENTAL PROTECTION AGENCY - VACANT
Lisa Jackson, a chemical engineer and the first black administrator of the agency, announced last month she planned to leave. Jackson battled Republican lawmakers and industry groups who accused the agency of overreaching as it cracked down on carbon emissions and mercury pollution.
- Christine Gregoire - (See Energy section above)
- Bob Perciasepe - Jackson's deputy and the EPA's acting administrator has already been through the Senate confirmation process, which could be difficult for any new candidate because of Republican anger over EPA rules.
- Gina McCarthy - the assistant administrator of EPA's Office of Air and Radiation is well-known on Capitol Hill, and once worked for 2012 Republican presidential candidate Mitt Romney when he was Massachusetts governor.
- Mary Nichols - chairman of the California Air Resources Board, who is overseeing a state-run cap-and-trade system for climate-changing greenhouse gases.
- Kathleen McGinty - protege of Gore and former secretary of the Pennsylvania Department of Environmental Protection.
OFFICE OF MANAGEMENT AND BUDGET - VACANT
The top job at the OMB has been vacant for a year since Jack Lew moved into the chief of staff role. It has been run by Jeff Zients, deputy budget director since 2009, who is considered a strong candidate to officially take the top job.
Other possible candidates:
- Douglas Elmendorf - an economist who has been director of the Congressional Budget Office since 2009. Elmendorf has worked at the Federal Reserve, the Council of Economic Advisers, and the Treasury Department.
- Gene Sperling - Obama's National Economic Council director, a position he also held under President Bill Clinton. Before taking up his latest post, Sperling was a Treasury counselor under Geithner, providing policy advice on fiscal issues, job creation and other domestic policies.
- Jason Furman - deputy director of the National Economic Council. A veteran number-cruncher in many budget battles, he was an economist at the White House Council of Economic Advisers and on the National Economic Council in the Clinton administration.
UNITED STATES TRADE REPRESENTATIVE - COULD SOON BE VACANT
USTR Ronald Kirk has said he plans to leave. He could be offered another Cabinet-level post such as Commerce secretary, but there is speculation that he will opt for a private-sector job or seek state-wide office in his home state of Texas.
- Michael Froman - now chief White House international economic affairs adviser, who attended Harvard Law School with Obama and has long been considered a likely successor to Kirk.
- Demetrios Marantis - deputy U.S. trade representative for Asia and Africa and former chief international trade counsel for Senate Finance Committee Chairman Max Baucus.
- Michael Punke - U.S. ambassador to the World Trade Organization, who worked for Baucus from 1991 to 1992 as international trade counsel before joining the Clinton White House as director for international economic affairs.
- Lael Brainard - Treasury undersecretary for international affairs. She has been heavily involved in trade and currency talks with China and broader economic discussions with the Group of 20 leading developed and developing countries.