Unlike previous presidential transitions, which normally take place during the roughly 10-week period between the election in the first week of November and the inauguration on January 20, Biden's presidential transition was shortened somewhat because the General Services Administration under the outgoing first Trump administration did not recognize Biden as the "apparent winner" until November 23.

Trump continued to falsely insist that he had won, alleging without evidence that Biden's increasing lead was due to widespread fraud, corruption, and other misconduct.

The declaration marked the official start of the transition, and withholding it from the Biden team had denied them $6.3 million, office space, government website status, and access to agencies.

[16][17] For this reason, many pundits and editorial writers would insist that Biden would need to win by a landslide to prevent Trump from challenging the result.

Murphy's withholding of the letter also blocked President-elect Biden's transition team from accessing several million dollars in federal transition funds for salaries and other costs, establishing government email addresses, and working with the Office of Government Ethics on required financial disclosure and conflict-of-interest forms for incoming nominees.

"[38][39] The letter was signed by several experts in presidential transitions: Joshua Bolten, President George W. Bush's former chief of staff; Mike Leavitt, former governor of Utah and Bush's Secretary of Health and Human Services; Mack McLarty, Bill Clinton's former chief of staff; and Penny Pritzker, Barack Obama's Secretary of Commerce.

[39] Andrew Card, the first White House chief of staff under George W. Bush, expressed concern about the delay, noting that "the 9/11 Commission had said if there had been a longer transition [in 2000] and there had been cooperation, there might have been a better response, or maybe not even any attack".

[40] Four former Secretaries of Homeland Security, Tom Ridge, Michael Chertoff, Janet Napolitano, and Jeh Johnson, called upon Murphy to initiate the transition, writing in a joint statement: "Our country is in the middle of twin crises: a global pandemic and a severe economic downturn.

[45] Breaking with recent precedent, the letter did not call Biden "president-elect", instead fulfilling her requirements under the Act without implying that he won the election.

[47] Meetings between the transition team and the administration began with the formation of two councils in May 2020,[48][49] around the time the former vice president had clinched the Democratic nomination.

[57][58] Key responsibilities of a presidential transition include the identification and vetting of candidates for approximately 4,000 non-civil service positions in the U.S. government who serve at the pleasure of the president; arranging the occupancy of executive residences including the White House, One Observatory Circle, and Camp David; liaising with the United States Strategic Command for receipt of the Gold Codes; and briefing senior personnel about a new administration's policy priorities.

Before naming any White House staff or cabinet appointments, Biden announced that he will appoint a COVID-19 task force, co-chaired by former Surgeon General Vivek Murthy, former Food and Drug Administration Commissioner David Kessler and Yale University epidemiologist Professor Marcella Nunez-Smith, to replace the previous White House Coronavirus Task Force.

[69][70] Biden pledged a larger federal government response to the pandemic than Donald Trump, akin to President Franklin D. Roosevelt's New Deal following the Great Depression.

This would include increased testing for the COVID virus, a steady supply of personal protective equipment, distributing a vaccine and securing money from Congress for schools and hospitals under the aegis of a national "supply chain commander" who would coordinate the logistics of manufacturing and distributing protective gear and test kits.

Biden also pledged to invoke the Defense Production Act more aggressively than Trump in order to build up supplies, as well as the mobilization of up to 100,000 Americans for a "public health jobs corps" of contact tracers to help track and prevent outbreaks.

[71] "Other members are Dr. Luciana Borio, Rick Bright, Dr. Ezekiel Emanuel, Dr. Atul Gawande, Dr. Celine Gounder, Dr. Julie Morita, Michael Osterholm, Loyce Pace, Dr. Robert Rodriguez and Dr. Eric Goosby.

[77] On November 22, 2020, Bloomberg News and the New York Times reported that Biden had selected Tony Blinken as his nominee for secretary of state.

[118] President-elect Biden also stated he would urge all Americans to wear a mask for the first 100 days of his presidency in an effort to curb the COVID-19 pandemic.