Here is how the transition is unfolding. All times Eastern.
Dec 14, 2020, 11:55 AM EST
Electoral College begins voting in first four states
The Electoral College kicked off voting in four states at 10 a.m. with Indiana, New Hampshire, Tennessee and Vermont being the first states slated to cast electors. While the Electoral College meets on the same day, each state determines when and where its electors meet.
Biden is expected to reach 270 votes -- the number need to win the presidency -- when California's electors vote at 5 p.m.
When will electors vote in the key battlegrounds?
*Arizona*: 12 p.m.
*Georgia:* 12 p.m.
*Michigan:* 2 p.m.
*Nevada:* 11:30 a.m.
*Pennsylvania:* 12 p.m.
*Wisconsin:* 1 p.m.
Based on the election results, Biden is anticipated to have 306 electoral votes by the end of the day, compared to Trump’s 232.
-ABC News' Kendall Karson
Dec 14, 2020, 9:45 AM EST
Overview: Biden slated to speak after Electoral College votes
Starting at 10 a.m. ET and rolling through the day, electors cast their votes on Monday for president and vice president in state capitols across the country -- another step towards enshrining Biden's victory and a step that will happen irrespective of Trump's last-ditch effort to overturn the result.
Biden is slated to deliver remarks on the Electoral College vote certification and "the strength and resilience of our democracy" from Wilmington, Delaware, around 8 p.m. Trump has an executive order signing on his schedule and has continued to air his grievances with the election on Twitter.
Monday's casting of electoral votes is traditionally little more than a formality with federal law requiring electors to meet the "Monday after the second Wednesday in December of presidential election years" -- but as Trump resists his defeat at every turn and wages long-shot legal battles with baseless claims of fraud, the meeting comes at a tense and fragile moment for the country's democratic institutions. Biden’s margin of victory in the Electoral College is expected to be 306 votes to Trump's 232, if there are no surprises.
Electors gather in each of their respective states and the nation's capital to cast separate paper ballots for president and vice president at places determined by the state legislature. Most of the meetings will be on cam via livestream and in the middle of a pandemic, but in Michigan, another threat interrupted the plan.
Officials announced late Sunday that the state legislature's office buildings will be closed due to "credible threats of violence" after Michigan’s 16 electors meeting were scheduled to cast their ballots at the state Capitol in Lansing. In Arizona, electors were given an undisclosed location to meet and cast their ballots in an effort to avoid any confrontation with protesters.
It's unclear how Trump's allies and supporters, particularly those in Congress who have fallen in line with his refusal to accept the loss -- despite Friday's final rejection at the Supreme Court -- will respond to Biden's victory once the Electoral College voting is complete.