Los Angeles' Skid Row contains one of the largest concentrations of homeless people in the United States. Robyn Beck /AFP/Getty Images hide caption

itoggle caption Robyn Beck /AFP/Getty Images

Martha Castro lives on the streets in Los Angeles' Skid Row neighborhood. She's still resistant to the idea that she can now get health coverage because of California's expansion of Medicaid. Anna Gorman/Kaiser Health News hide caption

itoggle caption Anna Gorman/Kaiser Health News