After being without health insurance for two years, Miranda Childe of Hallandale Beach, Fla., found a plan she could afford with financial aid from the government using the Affordable Care Act's exchange. Childe, 60, bought an HMO plan from Humana, one of the nation's largest health insurance companies, and received a membership card in time for her coverage to kick in on May 1. But instead of being able to pick a primary care physician to coordinate her health care, Childe says she repeatedly ran into closed doors from South Florida doctors who are listed in her plan's provider network but refused to see patients who bought their coverage on the ACA exchange.