They were given a pardon.
As a candidate, Carter himself had said he advocated "pardon" -- a term he preferred over "amnesty." He said, "Amnesty means that what you did was right. Pardon means that what you did, whether it's right or wrong, you are forgiven for it. And I do advocate a pardon for draft evaders. ... Now is the time to heal our country after the Vietnam war. ... I hope to bring about an end to the divisiveness that has occurred in our country as a result of the Vietnam war."
On his second day in office, President Carter in fact did pardon draft dodgers. This applied only to civilians who evaded the draft. It did not apply to active duty military personnel who went absent without leave (AWOL) or deserted their units during the war.