The Merced County Sheriff's Office says the 59-year-old victim was found inside a home on Dunn Road just after 9:30 pm on Tuesday.
The victim told deputies his 61-year-old housemate was the one who stabbed him.
He was taken to a local hospital with non-life-threatening injuries.
Detectives have not yet determined a motive for the stabbing.
Anyone with information is asked to call the Merced County Sheriff's Office.