When Lisa Melody French needed back surgery after a car accident, she went to a hospital near her home outside Denver, which reviewed her insurance information and told her she would be personally responsible for paying about $1,337.

But after the surgery, the hospital claimed that it had “misread” her insurance card and that she was, in fact, an out-of-network patient, court papers said. As a result, Centura Health, which operated the hospital, billed her $229,112.13. When she didn’t pay, Centura sued her.

“I was scared about it,” said Ms. French, 60, a clerk at a trucking company, who eventually filed for bankruptcy. “I didn’t understand because I kind of relied on the hospital and my insurance company to work out what I needed to pay.”

This week, after a yearslong legal battle, the Colorado Supreme Court ruled that Ms. French did not have to pay nearly $230,000 for the spinal fusion surgery she underwent at St. Anthony North Hospital in Westminster, Colo., in 2014.

It said she would have to pay only $766.74, apparently reflecting the remainder of her balance, as previously determined by a jury.

“I was very happy,” Ms. French said on Friday. “I was glad not just for me, but for other people. I think most people don’t get, like I didn’t get, how insurance and hospitals work.”

Centura Health did not immediately respond to requests for comment.

The unanimous ruling capped what Ms. French described as a stressful ordeal that began when her doctor ref