Sierra Occupational Services Medical Clinic Occupational Medicine is their Medial specialty. Sierra Occupational Services Medical Clinic is located on 1429 W Fremont St A in Stockton. They can be reached by phone by calling (209) 546-7767 . They can be reached by calling (209) 546-7767 . They rank #1 on MojoPages for Medical Clinics. They have a total of 4 reviews, 1 positive review and 3 negative reviews.