The Mammoth Lakes branch is at the Mono County Building, 1290 Tavern Road, Tioga Room. It is listed Tuesday/Thursday 9–noon and 1–4 p.m., or by appointment, and may close unexpectedly because of building or weather issues. Call before travelling.
Telephone representatives are listed Monday–Friday, 7 a.m.–5 p.m.; automated case information is available 24/7. The office page separately lists visiting hours of 8 a.m.–5 p.m.
The Yreka office is now at 520 South Main Street. The Alturas office is at 120 North Main Street with entry from the alley; each branch has its own hours.
The main office closes on the third Tuesday of each month, 8–11 a.m., for a staff meeting. Courthouse walk-in help has separate limited days and hours; it is unavailable Tuesday and Friday.
Customer-service window hours end at 4:30 p.m.; cashiers and telephone assistance have later hours. Check any selected-Saturday appointment separately.
Beginning October 7, 2026 the staffed call center is temporarily closed Wednesdays. It remains listed Monday, Tuesday, Thursday and Friday, 9 a.m.–4 p.m.; office caseworkers may still assist throughout the week. A January 2027 return to five days is an expectation, not a confirmed change.
Visit the Riverside office at 2081 Iowa Avenue. The separate agency mailing address is 2041 Iowa Avenue. Interviews and telephone assistance are 8 a.m.–5 p.m.; local cash payments start at 7:30 a.m. on listed weekdays.
Genetic testing has its own branch schedule: Ontario lists Wednesdays and Victorville Tuesdays, 8 a.m.–4:30 p.m. These are separate from regular office hours.
The dated county announcement identifies 277 South Street, Suite R as the new office beginning June 15, 2026. The general contact page still lists 1200 Monterey Street; use the dated move notice and confirm visiting hours with the agency.
The lobby is listed Monday–Thursday, 9 a.m.–4 p.m. Fridays the lobby is closed while the call center remains open 8 a.m.–4:45 p.m., closing noon–1 p.m.
Caseworkers are available 9 a.m.–4 p.m.; the lobby self-service kiosk and drop-box have separate 8 a.m.–5 p.m. hours. Do not treat self-service hours as staffed caseworker availability.
The virtual walk-in lobby is a pilot listed Wednesday–Friday, 8:30 a.m.–4 p.m. This differs from the physical office’s Monday–Friday business hours. Confirm pilot availability before connecting.