A day before a long-scheduled surgery, Aminatou Sow got an unexpected phone call: Her hospital wanted her to pay her share of medical bill before the operation took place.

Sow has a $4,000 deductible, and the hospital representative asked for that entire amount upfront. The representative suggested that she provide a credit card number that could be charged.

Sow, who hosts the Call Your Girlfriend podcast, recounted the experience on Twitter:

Money really is at the heart of everything that is fucked up with our healthcare. Case in point: I’m scheduled for surgery tomorrow morning. It’s been on the books for weeks. I’ve gone through extensive pre-testing and have followed up with the hospital every step of the way — Aminatou Sow (@aminatou) January 22, 2018

Typically you get a call the day before surgery to confirm what time you’re supposed to show up. NBD. Talked to the surgical coordinator. Got my checkin time. I asked if all my paperwork was in order. Before that I was in touch with my insurance. Yup all good. — Aminatou Sow (@aminatou) January 22, 2018

Then I get a call from someone in the finance department of the hospital. Along the lines of “oh your deductible is high and you haven’t met any of it yet” yes no shit Jennifer from finance. It’s the 22nd day of January. Nobody has hit their deductible. — Aminatou Sow (@aminatou) January 22, 2018

Surgery is in ~18 hours and this woman is telling me that I have to pay my entire deductible before surgery. “Please use a credit card” How polite. I am stunned. There is a long silence and she says “you at least have to pay half to get this surgery” — Aminatou Sow (@aminatou) January 22, 2018

Every step of the way I have asked the hospital and the insurance company if everything is in order because I’m a black woman and I don’t trust nobody to save me. Nobody said a peep about paying the deductible upfront. Also this is so mercenary. Pay or no care for you — Aminatou Sow (@aminatou) January 22, 2018

I calmly ask her to walk me through the regulations that stipulate this. I understand why hospitals want to be paid upfront but it is disgusting to do it this way and withhold care from people who need it — Aminatou Sow (@aminatou) January 22, 2018

I’m fine. I can pay this dumb deductible. It’s $4000 which thankfully is also my out of pocket max. I’d budgeted for this and it’s not lost on me how incredibly privileged I am to be able to just swipe my chase sapphire and make this problem go away. — Aminatou Sow (@aminatou) January 22, 2018

but it really makes me sick to my stomach to think of people who can’t afford this + how incredibly fucked up this is. The game is so dirty. You go through all these hoops even get insurance and then they still treat you like dirt.

Anyway cancer isn’t free. Support single payer! — Aminatou Sow (@aminatou) January 22, 2018

The hospital representative she spoke with warned her she might not be able to get the surgery if she didn’t pay upfront, Sow told me over email.

Sow had expected to pay her deductible this year. She knew the surgery was expensive. She just didn’t think it would happen like this, with a call 18 hours before surgery requesting payment with little warning — and tethering that upfront payment to her ability to get medical care.

Her experience is, frustratingly, a relatively common one in the American health care system. Doctors are increasingly asking patients to prepay their medical costs. This even happened to me recently: In January, I received a bill for a small medical procedure that won’t happen until June — six months away.

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As NPR reported two years ago, some doctor offices are even exploring keeping their patients’ credit cards on file — something akin to a bar tab, except instead of drinks, people are buying medical care.

This can, as Sow points out, leave low-income patients in a bind if they don’t have the cash on hand for an upfront payment, especially when they only learn of the costs hours before a scheduled surgery.

And with deductibles on the rise, the costs that patients are expected to pay are on the rise too. The average deductible for Americans who receive insurance at work is now $1,478 — 63 percent higher than it was in 2011, according to the Kaiser Family Foundation.

Deductibles in the individual market are typically much higher, more in the range of Sow’s $4,000 deductible. And that plan is still expensive: Sow told me she pays a monthly premium of $668 for her coverage.

These high deductibles are, in part, what’s driving hospitals to increasingly ask patients to pay their bills in advance. They’re worried about providing services and never getting paid, now that patients — rather than insurance companies — are responsible for a good chunk of their payment.

Patients could try to protest the upfront payment, but they have little leverage. Those who have coverage through federal government programs like Medicare can refuse upfront payment. The rules for private health insurance that covers most working-age Americans aren’t nearly as clear-cut. And the situation often leaves patients with little leverage, if any, when needed medical care is on the line.

Have you had a recent trip to the emergency room? Vox is running a year-long medical billing series about emergency bills. Learn more and share yours at erbills.vox.com.