Foster faces additional felony charges of forcefully attempting to prevent a victim from reporting a crime and possession of an assault weapon, as well as a misdemeanor for possession of a large-capacity weapon magazine.
He'd face more than 11 years in prison if convicted.
"Our focus is on holding accountable those who hurt their intimate partners," said prosecutor Kevin Smith. "Our office handles between four and five thousand domestic violence cases each year. We only hope that this case illuminates the tragic regularity of the rest."
The woman flagged down a stranger's car on Feb. 11 in order to call 911. She informed police that Foster "dragged her by her hair, physically threw her out of the house, and punched her in the head eight to 10 times," according to the DA's office. She suffered a ruptured eardrum.
The 49ers released a statement via NFL Network's Ian Rapoport to indicate they are aware of the situation and it could affect Foster's status with the club:
The 49ers organization is aware of today's disturbing charges regarding Reuben Foster. We will continue to follow this serious matter. Reuben is aware his place in our organization is under great scrutiny and will depend on what is learned through the legal process.