Call your county's Medi-Cal office for questions about your Medi-Cal eligibility or if your address or phone number changes. You may also qualify for Medi-Cal through Social Security if you get Supplemental Security Income (SSI). If so, call the Social Security Administration (SSA) office. Mariposa County  Medi-Cal office: 209-966-2000 | Toll Free: 800-549-6741  SSA office: Call 209-966-2000 to schedule an appointment. Appointments are available on Wednesday and Thursday from 9 a.m. to noon.  San Benito County   Medi-Cal office: 831-636-4180  SSA office: Call 800-722-1213 to make an appointment at the office closest to you.