The California Highway Patrol and a passing motorist reported seeing a person in the water near the western portion of the bridge at about 7:15 a.m., Lt. j.g. Jeremy Pichette said.
The Coast Guard dispatched a helicopter and 25-foot response boat to the area, and the man was pulled aboard the boat at about 8 a.m., Pichette said.
The man, who was conscious and breathing when he was pulled from the Bay, was given oxygen by paramedics and taken to a hospital in San Francisco for further treatment.
The CHP and the Foster City Fire Department also responded to the incident.