Unfortunately, there’s even more people in that situation than before. The good news is the Bay Area has a variety of medical clinics available for people of limited means.
If you live in Berkeley, you might first look into the Berkeley Free Clinic. They provide general medical and dental services and some tests. If you don’t live in Berkeley, or if they don’t provide the specific services you need, the Berkeley Free Clinic website also includes a list of General Medical Primary Care Clinics available in the greater Bay Area. The list includes a brief synopsis of each clinic’s criteria and what services they provide.