What is prior authorization?

Before your insurer will cover certain treatments, they require your doctor to submit a prior authorization request — documentation explaining why you need the treatment, why alternatives won't work, and why it's medically necessary for your specific situation. The insurer then approves or denies coverage before treatment begins.

Prior authorization was designed to prevent unnecessary or duplicative care. In practice, for rare disease patients it frequently delays appropriate treatment, requires patients to try and fail treatments that are known to be ineffective for their condition, and creates an administrative burden that falls almost entirely on the patient and their care team.

The American Medical Association reports that 94% of physicians say prior authorization has delayed necessary patient care, and 80% say it sometimes leads to patients abandoning treatment entirely.

Prior authorization protocols are built around common conditions and standard treatment pathways. Rare disease patients fall outside those pathways almost by definition. The clinical criteria insurers use to evaluate prior auth requests were often written without rare disease presentations in mind, the treatments rare disease patients need are frequently newer or off-label, and the evidence base for rare disease treatments is often thinner — not because the treatments don't work, but because small patient populations make large clinical trials difficult.

This means a prior authorization denial for a rare disease patient is often not a clinical judgment — it's a protocol mismatch. The treatment works, but the insurer's criteria weren't written to recognize it. Organizations like NORD (National Organization for Rare Disorders) have documented this disparity extensively.

Step therapy — also called fail-first — is a specific type of prior authorization requirement. It requires patients to try and fail a series of less expensive treatments before the insurer will approve the treatment their doctor actually recommended.

For rare disease patients, step therapy creates a specific problem: you may be required to try treatments that are known to be ineffective or actively harmful for your condition, the "steps" may take months or years, and the harm caused by delaying appropriate treatment may be irreversible.

Many states have enacted step therapy exception laws. The steptherapy.com state law tracker is the most comprehensive resource for finding your state's specific protections.

A denial letter from your insurer will include a specific denial reason — usually "not medically necessary," "experimental or investigational," or "step therapy not completed." The letter must also include information about your right to appeal.

You have two formal options: an internal appeal (reviewed by your insurer) and, if that fails, an external review by an independent organization. Under the Affordable Care Act, you have the right to both. The external reviewer's decision is binding on your insurer — meaning if they side with you, the insurer must cover the treatment.

For detailed step-by-step guidance on the appeal process, see our guide: How to appeal an insurance denial for rare disease.

Separate from the formal appeal process, your doctor can request a peer-to-peer review — a direct phone call between your treating physician and the insurer's medical director. This conversation can sometimes resolve a prior authorization denial faster than a written appeal, particularly if the denial resulted from incomplete clinical information rather than a policy disagreement.

Ask your doctor's office specifically about requesting a peer-to-peer review. Not all physicians are aware this option exists, and insurers are not required to proactively offer it. The window for requesting peer-to-peer review is usually short — often 3 to 5 business days after the denial.

The patients who win prior authorization appeals are the ones who have documentation ready before they start the appeal process. Keep records of: every prior treatment you've tried and when, every adverse reaction or documented failure, every specialist you've seen and what they recommended, and any clinical guidelines from your condition's foundation or specialist society that support your treatment.

A consistent treatment history documented in writing — not just in your chart — significantly strengthens any prior authorization appeal. Start this documentation now, not after you receive a denial.