What is prior authorization?
Prior authorization (also called pre-authorization or pre-approval) is a requirement from your Medicare plan that you get approval before receiving certain services, procedures, or medications. The plan reviews whether the service is medically necessary before agreeing to cover it.
Prior authorization is mainly an issue for Medicare Advantage plans and Part D prescription drug plans. Original Medicare (Parts A and B) rarely requires prior authorization, though some services like non-emergency ambulance transportation do need advance approval.
What typically requires prior authorization?
- Non-emergency surgeries — Joint replacements, spinal procedures, bariatric surgery
- Advanced imaging — MRI, CT scans, PET scans
- Specialty medications — High-cost drugs, biologics, cancer treatments
- Durable medical equipment — Power wheelchairs, home oxygen, CPAP machines
- Home health care — Extended home health visits beyond initial assessment
- Inpatient rehabilitation — Stays at rehabilitation facilities
- Out-of-network care — Any non-emergency care outside your plan's network (MA plans)
- Certain outpatient procedures — Some plans require prior auth for outpatient surgical procedures
Emergency care never requires prior authorization. If you have a medical emergency, go to the nearest emergency room. Your plan must cover emergency services regardless of prior authorization requirements or network status.
How the process works
In most cases, your doctor handles the prior authorization process. Here's what typically happens:
- Your doctor determines you need a specific service or medication
- Your doctor's office submits a prior authorization request to your plan
- The plan reviews the request based on medical necessity criteria
- The plan issues a decision — approval, denial, or request for more information
- If approved, you can proceed with the service
| Request type | Decision deadline |
|---|---|
| Standard (non-urgent) | 14 calendar days |
| Expedited (urgent) | 72 hours |
| Part D medications (standard) | 72 hours |
| Part D medications (expedited) | 24 hours |
If your request is denied
If your prior authorization is denied, you have the right to appeal. The appeals process has five levels:
- Plan reconsideration — Ask your plan to review the decision. They must respond within 30 days (standard) or 72 hours (expedited).
- Independent Review Entity (IRE) — If the plan upholds the denial, it's automatically sent to an independent reviewer.
- Office of Medicare Hearings and Appeals (OMHA) — A hearing before an administrative law judge (if the amount in dispute meets the minimum threshold).
- Medicare Appeals Council — Review by the Departmental Appeals Board.
- Federal court — Judicial review in U.S. District Court.
Don't skip the appeal. Studies show that a significant percentage of Medicare prior authorization denials are overturned on appeal. If you believe a service is medically necessary, exercise your right to appeal.
Colorado-specific considerations
- State oversight — The Colorado Division of Insurance oversees insurance practices in the state and can help with complaints about prior authorization delays or denials from Medicare Advantage plans.
- SHIP assistance — Colorado SHIP counselors can help you understand the appeals process and assist with filing appeals at no cost. Call 1-888-696-7213.
- CMS reforms — Recent federal rules have shortened prior authorization timelines and required plans to provide more specific reasons for denials. These protections apply to all Colorado beneficiaries.
Tips for Colorado beneficiaries
- Ask your doctor upfront whether a recommended service requires prior authorization from your plan.
- Check your plan's formulary before asking your doctor to prescribe a new medication — some drugs require prior auth, step therapy, or quantity limits.
- Keep records of all prior authorization requests, approvals, and denials.
- Don't receive the service before approval — unless it's an emergency. You could be responsible for the full cost.
- Consider Original Medicare if prior authorization requirements are a major concern. Original Medicare has significantly fewer prior auth requirements than most Medicare Advantage plans.