Davis tweeted Monday morning that he has filed his letter requesting reinstatement to the NFL and the team.
The onus now falls on the NFL to allow Davis' reinstatement and the 49ers to clear a spot on their 90-man roster should they want to retain his rights. Davis is currently on the reserve/retired list.
Davis took what was expected to be a temporary break from the NFL last June, an announcement that came on the heels of a 2014 season in which he started just seven games and dealt with knee, hamstring and head injuries.
Monday's declaration that he's aiming to return is no surprise, however, as he had indicated a return was possible if not probable when he walked away.
"After a few years of thought, I've decided it will be best for me to take a year or so away from the NFL," Davis said in a statement last year. "This will be a time for me to allow my brain and body a chance to heal. I know many won't understand my decision, that's OK.
"I'm simply doing what's best for my body as well as my mental health at this time in my life."
Davis, 26, started 71 games in five seasons for the 49ers before he walked away.
While San Francisco has needed help at right tackle since Davis' departure, it's unclear whether the team plans to keep him upon reinstatement, what kind of physical condition he's in or what his role would be upon returning.