But, funny thing: She also says insurance fights are easy. For her. She's been helping people win them for 30 years.
For Fox, it started when an insurance provider wanted to cancel lifesaving cancer surgery for her mom.
Fox, then a young associate at a big firm, called the company right away and said, "I am out the door to sue you over this."
The company caved. And because Fox had left her office door open, her assistant heard the whole thing. Soon, Fox had a line of support staff from the law firm who needed help with their insurance problems. She enjoyed helping them and found it easy. Her legal work involved crafting complex financial instruments like mortgage-backed securities, and she looked at health insurance policies as just another contract.
Then she went back to school and studied legal history, especially the "enclosure" movement that started in medieval England. In theory, English peasants had a legal recourse to be compensated if the lord of the manor wanted their homes or farms. But in practice, they had no way to pursue it.
"And as I was studying it," she said, "I was like, 'This looks like health insurance. This looks exactly like health insurance.'"
Fox's conclusion: "Process without meaningful access to process is no process at all."
She opened a solo legal practice to help people get that access, to get what their insurance policies said they were entitled to.
After a while, she got interested in policy — solving more than one person's problem at a time — and for the last 16 years, she's been a law professor at the University of South Carolina.
But her phone still rings. Last year, Fox talked someone through an appeal while she was in the grocery store. It worked, too.
"I know what contracts look like, without even thinking about it," she said. "I've been doing this for 30 years, so it's not like a brag. It's like, duh. It's like a plumber knowing what a pipe looks like."
Fox has a lot to teach us. And class is in session.
"An Arm and a Leg" is a co-production of KHN and Public Road Productions.
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This article was reprinted from khn.org with permission from the Henry J. Kaiser Family Foundation. Kaiser Health News, an editorially independent news service, is a program of the Kaiser Family Foundation, a nonpartisan health care policy research organization unaffiliated with Kaiser Permanente.