When Dr. Zachary Sussman went to Physicians Premier ER in Austin for a COVID-19 antibody test, he assumed he would get a freebie because he was a doctor for the chain. Instead, the free-standing emergency room charged his insurance company an astonishing $10,984 for the visit — and got paid every penny, with no pushback.

The bill left him so dismayed he quit his job. And now, after ProPublica's questions, the parent company of his insurer said the case is being investigated and could lead to repayment or a referral to law enforcement.

The case is the latest to show how providers have sometimes charged exorbitant prices for visits for simple and inexpensive COVID-19 tests. ProPublica recently reported how a $175 COVID-19 test resulted in charges of $2,479 at a different free-standing ER in Texas. In that situation, the health plan said the payment for the visit would be reduced and the facility said the family would not receive a bill. In Sussman's case, the insurer paid it all. But those dollars come from people who pay insurance premiums, and health experts say high prices are a major reason why Americans pay so much for health care.