Last October, police said Maxwell showed signs of intoxication when he was arrested following allegations that he pointed a handgun at the head of a woman who had delivered food to his Scottsdale home.
Under the terms of the agreement, Maxwell will be required to complete a probation period as well as community service. Upon completion, the designated felony will be reduced to a misdemeanor.
He'll be sentenced on June 4 in Maricopa County Superior Court.
"Accepting responsibility is the first step in working to make amends for my lapse in judgement," Maxwell said in a statement. "I am truly sorry for the pain that my actions have caused, and while they are not representative of who I am, I understand that I have to earn back the trust and respect of those around me."
Maxwell, 27, has appeared in three games this season, batting .273 with two RBIs.
Maxwell was the only player in Major League Baseball to take a knee last season during the national anthem to protest social injustice.
The Associated Press contributed to this report.