The two-alarm fire was reported at 8:51 a.m. at 1405 Phelps Ave., near San Tomas Expressway, San Jose fire Capt. Cleo Doss said.
Crews arrived at 8:58 a.m. and found one unit engulfed in flames, Doss said. All residents got out of their apartments safely.
The fire was extinguished at 9:13 a.m., Doss said.
The American Red Cross has been called to assist the two residents who lived in the damaged unit.
No other units were affected by the blaze and no injuries were reported, Doss said.
The cause of the fire is under investigation.