Challenges to proton therapy denials turn on challenging commercial insurers’ internally-developed clinical guidelines that are at odds with generally accepted standards of care. Over the last 10 years, insurers have shifted the bases for their proton therapy denials. At first, insurers relied on internal guidelines to deny treatment on the basis that proton therapy was considered “experimental” or “investigational.” More recently, however, denials are based on a determination that proton therapy is “not medically necessary.” These are two very distinct bases for denial with significant legal implications.

A denial on the basis that the requested therapy is “experimental” or “investigational” draws from exclusionary language under the plan. Such a denial places the burden of proof on the insurer to show that proton therapy is, in fact, “experimental” or “investigational” under the terms of the plan.


On the other hand, federal courts have held that plan language limiting coverage to treatment considered “medically necessary” is a term of coverage. Baxter v. MBA Grp. Ins. Tr. Health & Welfare Plan, 958 F. Supp. 2d 1223, 1228–30 (W.D. Wash. 2013). The burden of proof in an ERISA case to establish that proton therapy is “medically necessary” rests with the requesting insured. As such, it is now more common to see proton therapy denied on the basis of medical necessity. An insurer may define “medically necessary” with a series of bullet-pointed requirements including that the requested procedure be “not investigational.” Woodruff v. Blue Cross & Blue Shield of Alabama, No. 2:16-CV-00281-SGC, 2018 WL 571933, at *6 (N.D. Ala. Jan. 26, 2018). Nevertheless, the burden of proof remains on the insured to prove that proton therapy meets all terms of the definition. For example, the insured may have to prove that proton therapy is “appropriate and necessary for the diagnosis or treatment,” “in accordance with standards of good medical practices accepted by the organized medical community,” and “performed in the least costly setting, method or manner, or with the least costly supplies required by your medical condition.” Id. Often times, plan language will require an insurer to prove that proton therapy is superior to other traditional, less expensive forms of radiation like intensity modulated radiation therapy (IMRT), brachytherapy, or 3D conformal radiation therapy (CRT). These requirements prove a thick barrier to access.

Internal clinical guidelines allow the insurance company to load the file with self-serving citations to outdated and unreliable scientific literature. In addition, insurance companies often assert that there are no studies that definitively prove the superiority of the requested treatment (proton therapy) over the treatment the insurance company wants to pay for (traditional radiation modalities). The problem with this requirement is that it would be impossible and, perhaps, unethical to conduct such a randomized controlled study. Indeed, no study can purposefully treat a patient with both proton therapy and IMRT.

Rad Oncology Homepage