The only current Republican in the Cabinet, Transportation Secretary Ray LaHood, has not indicated whether he will leave the administration.
Obama said Solis was a "tireless champion for working families" and had been a key member of his economic team during a first term marked by efforts to rebound from the recession. She won praise from labor unions for an aggressive enforcement of wage and hour laws and job safety regulations but business groups criticized her as not taking a more cooperative approach.
Solis is expected to return home to California to run for a seat on the Los Angeles County Board of Supervisors.
Sebelius, a former Kansas governor and insurance commissioner, had been widely expected to stay on to shepherd Obama's health care overhaul to its fulfillment. The big push to cover some 30 million uninsured Americans starts next year.
Holder, who served in the Justice Department during the Clinton administration, has faced a rocky tenure as attorney general, dealing with civil rights and terrorism cases along with a botched gun smuggling probe along the Southwest border.
He ordered a review of CIA interrogations during the Bush era amid disclosures that agency interrogators once threatened to kill a Sept. 11 suspect's children and suggested another would be forced to watch his mother be sexually assaulted. The outcome of the exhaustive inquiry — it lasted three years and resulted in no criminal charges — prompted more criticism, this time from human rights groups.
Shinseki has sought to manage a large agency closely watched by returning troops as the war in Iraq ends and another one winds down in Afghanistan. He has dealt with problems ranging from homeless veterans, rising troop suicides and veteran unemployment and growing mental health care needs.
Associated Press writers Matthew Daly, Ricardo Alonso-Zaldivar and Pete Yost contributed to this report.