Army and Air Guard commands from nearly 30 states have so far pledged to help swear-in the 59th president of the United States later this month.
More than 4,000 troops are expected to be on hand when Mr Biden becomes president at noon on 20 January on the steps of the US Capitol.
“Every four years this is the biggest event that the National Guard works,” Air Force senior master sergeant Craig Clapper, spokesman for the DC National Guard, told military.com.
“Right now, we have commitments from multiple states for over 4,000 people, but that could easily go up to 7,000, or it could even decrease just depending on what the inauguration will look like.
“At this very moment, we don’t know exactly what it’s going to look like.”
Around 7,800 National Guard troops helped support Donald Trump’s inauguration, but Covid restrictions means that Mr Biden’s will be a scaled-down event.
Guard members will assist law enforcement and DC Park Police with crowd management, traffic control, communication support and emergency response services.
“We do street blockings, entry control points for certain areas, a lot of it is just crowd control,” added Mr Clapper.
“Normally for inaugurations, we are there a handful of days before. We have actually already had some personnel come in.”
Earlier this year more than 5,200 Guard members were in Washington DC to support police during George Floyd demonstrations in the city.
And although Guard officials say they do not expect protests on inauguration day, they insist they will be prepared.
“We always have the security aspect; if something were to happen in terms of an event that would require law enforcement, we are kind of there in a support role,” said Mr Clapper.
“In no inaugurations past have we had to go into any kind of law enforcement role.
“With this inauguration, we don’t anticipate that either, but we still plan for increased numbers of personnel in the area as a just-in-case scenario.”