When Paul Moser considers getting a coronavirus vaccine, he also thinks about his outstanding medical debt: $1,200 from a few urology visits that he has been unable to pay off.

Mr. Moser, a 52-year-old gas station cashier in New York State, has friends who were surprised by bills for coronavirus tests, and worries the same could happen with the vaccine. For now, he’s holding off on getting his shot.

“We were told by the legislators that all the testing was supposed to be free, and then surprise, it’s $150,” he said. “I agree it’s important to get vaccinated, but I don’t have a sense of urgency around it.”