Proton beam coverage suit against UnitedHealthcare moves forward Modern Healthcare Illustration / Getty Images A federal judge refused to toss a proposed class-action suit against UnitedHealthcare, with plaintiffs alleging the Minnetonka, Minn.-based insurer improperly denied benefits and did not live up to its fiduciary duty to cover a type of cancer treatment known as proton beam therapy. U.S. District Judge Allison Burroughs denied UnitedHealthcare's motion to dismiss on Monday. In March 2020, a court dismissed an individual claim on behalf of Kate Weismann, who paid $95,000 out-of-pocket for proton beam therapy to treat her cervical cancer. The court said that she would have to sue under a different provision of the Employee Retirement Income Security Act, or ERISA. While Weismann accused UnitedHealthcare of breaching its fiduciary duty, the judge said she should have sued the insurer for denial of benefits. Weismann amended her complaint and the court eventually consolidated her case with two others accusing UnitedHealthcare of wrongfully denying proton beam therapy for cancer treatment.