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In May 2021, a nurse at UnitedHealthcare called a colleague to share some welcome news about a problem the two had been grappling with for weeks.

United provided the health insurance plan for students at Penn State University. It was a large and potentially lucrative account: lots of young, healthy students paying premiums in, not too many huge medical reimbursements going out.

But one student was costing United a lot of money. Christopher McNaughton suffered from a crippling case of ulcerative colitis — an ailment that caused him to develop severe arthritis, debilitating diarrhea, numbing fatigue and life-threatening blood clots. His medical bills were running nearly $2 million a year.