Lori Lomas, an insurance agent with Feather Financial in Quincy, Calif., has noticed that her clients in San Francisco have many more health carrier options than her mountain neighbors. Pauline Bartolone for KXJZ hide caption

itoggle caption Pauline Bartolone for KXJZ

Insurance companies negotiate with hospitals and doctors the price of every treatment, procedure and medical service. That price differs from hospital to hospital — even health plan to health plan. Vincent Wartner/Science Source hide caption

itoggle caption Vincent Wartner/Science Source

Maritza Martinez worked with an insurance agent at a kiosk in a Miami mall to find the right health insurance plan for 2014. Joe Raedle/Getty Images hide caption

itoggle caption Joe Raedle/Getty Images