Health providers may bill however they choose — including in ways that could leave patients with unexpected bills for “free” care. Routine preventive care saddled an Illinois couple with his-and-her bills for “surgical trays.”

Sky-high bills from air-ambulance providers have sparked complaints and federal action in recent years. But a rural Tennessee resident fell through the cracks of billing protections — and a single helicopter ride could cost much of her estate's value.

There are legal safeguards to protect patients from big bills like out-of-network air-ambulance rides. But insurers may not pay if they decide the ride wasn’t medically necessary.

Agreeing to an out-of-network doctor’s own financial policy — which generally protects their ability to get paid and may be littered with confusing insurance and legal jargon — can create a binding contract that leaves a patient owing.

A man from Michigan was evacuated from a cruise ship after having seizures. First, he drained his bank account to pay his medical bills.

Suffering stomach pain, a Dallas man visited his local urgent care clinic — or so he thought, until he got a bill 10 times what he’d expected.

Even when patients double-check that their care is covered by insurance, health providers often send them bills as they haggle with insurers over reimbursement, which can last for months. It’s stressful and annoying — but legal.

A collection agency sought court authority to garnish a patient’s wages to pay a disputed surgery bill. But after the patient showed up in court to argue the bill was bogus, the judge declined to let the bill collector seize her money.

An Alabama teen was told he needed surgery for debilitating hip pain. But his family’s insurer denied coverage for the procedure, which lacked a medical billing code. Expected to pay more than $7,000, his father charged it to credit cards.

For snakebite victims, antivenom is critical — and costly. It took more than $200,000 worth of antivenom to save one toddler’s life after he was bitten by a rattlesnake.

A mom in Peoria, Illinois, took her 3-year-old to the ER one evening last December. While they were waiting to be seen, the toddler seemed better, so they left without seeing a doctor. Then the bill came.

A man in Chicago with a troubling symptom underwent a common procedure. Then he wanted to know why the hospital charged nearly three times its own cost estimate.