Michelina Moen lost her job and health insurance in April. Only weeks earlier she had begun to feel ill and not her usual energetic self — in what she describes as a textbook case of “really bad timing.” The Orlando, Florida, resident sought treatment in May. After a series of tests, doctors told Moen she had a rare kidney condition that would require months of treatment. “Losing the coverage ended up being worse than losing the job,” said Moen, 36, a dancer who had worked for both Walt Disney World and Universal Studios. “It was very stressful.” Moen rushed to find replacement coverage. With help from a social service agency, she enrolled in a plan through healthcare.gov, the federal Affordable Care Act insurance marketplace. Because she and her husband, Brett, were not working — he had been laid off by Disney, too — they qualified for federal subsidies, so the coverage cost her just $35 a month. Most of her medical expenses, which involve traveling frequently to Jacksonville for s...