What Is Prior Authorization? Why Your Insurance Makes You Wait

Your doctor says you need an MRI. Great — you want to know what's going on with your knee. But instead of scheduling it this week, the office tells you they need to "get authorization from your insurance first." That could take a few days. Or a few weeks. Or it could get denied entirely.

Welcome to prior authorization — one of the most frustrating parts of having health insurance in America.

Prior authorization (also called "prior auth" or "preauthorization") is when your insurance company requires your doctor to get approval before providing a specific treatment, test, procedure, or medication. The insurer reviews the request and decides whether it's "medically necessary" before they'll agree to cover it.

In theory, it's supposed to prevent unnecessary procedures. In practice, it often delays care that patients and doctors both agree is needed — sometimes with serious consequences.

How Prior Authorization Works, Step by Step

Here's what actually happens behind the scenes when your doctor orders something that requires prior auth:

1. Your doctor determines you need a service — an MRI, a specialist referral, a specific medication, a surgery, etc.
2. The doctor's office checks your insurance plan to see if that service requires prior authorization. (Not all services do — more on that below.)
3. The office submits a prior auth request to your insurer, including clinical documentation explaining why the service is medically necessary. This might include your medical records, test results, and the doctor's notes.
4. The insurance company reviews the request. This is typically done by a nurse reviewer or, for complex cases, a physician employed by the insurer (called a "medical director").
5. The insurer issues a decision: approved, denied, or "pended" (meaning they need more information).
6. If approved, you get a reference number and the service can be scheduled.
7. If denied, your doctor can submit additional information or file a formal appeal.

Key takeaway: Prior authorization is not your responsibility to initiate — it's your doctor's office that handles the paperwork. But it is your responsibility to follow up and make sure it's actually happening.

What Services Typically Require Prior Authorization?

Every insurance plan is different, but prior auth is commonly required for:

• Advanced imaging — MRIs, CT scans, PET scans (an MRI can cost $400–$3,500+, so insurers want to gatekeep these)
• Specialty medications — Especially expensive biologics, cancer drugs, and newer brand-name medications that can cost $1,000–$15,000+ per month
• Elective surgeries — Joint replacements, bariatric surgery, spinal procedures
• Mental health services — Extended therapy sessions, residential treatment, some psychiatric medications (see our guide on therapy costs)
• Durable medical equipment — CPAP machines, wheelchairs, prosthetics
• Out-of-network care — Using a provider not in your plan's network almost always needs pre-approval (learn more about in-network vs. out-of-network care)
• Physical therapy — Often approved in blocks (e.g., 12 sessions at a time)
• Home health services — Skilled nursing, home infusion therapy

Emergency care does NOT require prior authorization. If you go to the ER for a genuine emergency, your insurer must cover it regardless. The No Surprises Act also provides protections for emergency services.

How Long Does Prior Authorization Take?

This is the part that drives people crazy. Here are the typical timelines:

• Standard (non-urgent) requests: Insurance companies generally have 5–15 business days to respond, depending on your state's regulations and whether it's a commercial plan or government plan.
• Urgent/expedited requests: If your doctor marks the request as urgent (meaning a delay could seriously harm your health), the insurer typically must respond within 24–72 hours.
• Medicare Advantage plans: Must decide standard requests within 7 days and urgent requests within 72 hours. New CMS rules taking effect in 2026 are tightening these timelines further.
• Medicaid: Varies by state, but most require decisions within 3–14 days.

In reality? A 2024 American Medical Association (AMA) survey found that the average prior auth takes about 12 days to process, and 35% of physicians reported that prior auth led to a serious adverse event for a patient due to delays.

Key takeaway: If your doctor says the request is urgent, make sure they actually mark it as urgent with the insurer. The word "urgent" triggers faster review timelines that are legally required.

What Happens If Your Prior Authorization Is Denied?

Getting a denial letter is stressful, but it's not the end of the road. Here's what you can do:

1. Understand Why It Was Denied

The denial letter must include a reason. Common reasons include:

• The insurer doesn't consider the service "medically necessary"
• There's a less expensive alternative available (called "step therapy" — they want you to try cheaper options first)
• The documentation submitted was incomplete
• The service isn't covered under your specific plan

2. Ask Your Doctor to Submit a Peer-to-Peer Review

Your doctor has the right to speak directly with the insurance company's medical director — doctor to doctor. These "peer-to-peer" calls can be surprisingly effective. When a practicing specialist explains face-to-face why a treatment is necessary, denial rates drop significantly.

3. File a Formal Appeal

You have the legal right to appeal any denial. There are typically two levels:

• Internal appeal: The insurance company reviews the denial again, usually by a different reviewer.
• External review: An independent third party reviews the case. If the external reviewer sides with you, the insurer must cover the service.

For a detailed walkthrough, see our guide on how to appeal an insurance denial.

Key takeaway: About 50–60% of prior authorization denials are overturned on appeal. Don't give up after the first "no."

Why Do Insurance Companies Require Prior Authorization?

The insurance industry's answer: to ensure patients receive appropriate, evidence-based care and to control healthcare costs.

The more cynical (but not entirely unfair) answer: to create friction that discourages expensive treatments, even when they're necessary.

The truth is somewhere in between. Prior auth does catch some genuinely unnecessary procedures — there are cases where a simpler, cheaper test would give the same answer as a $3,000 MRI. But the system is widely regarded as overly burdensome:

• A 2024 AMA survey found that 94% of physicians said prior auth caused care delays.
• The average physician's practice spends nearly two full business days per week on prior authorization paperwork.
• 1 in 3 doctors reported that prior auth led to a patient's hospitalization.
• Some insurance companies have auto-denial algorithms that reject requests before a human even reviews them.

The Prior Authorization Reform Movement

There's growing bipartisan support for prior auth reform. Here's what's changing:

• CMS Interoperability Rule (2026): Requires Medicare Advantage, Medicaid, and marketplace plans to implement electronic prior auth systems, respond to standard requests within 7 days, and provide specific reasons for denials.
• State-level reforms: Over 30 states have passed laws limiting prior auth, including "gold card" programs that exempt doctors with high approval rates from prior auth requirements.
• The Improving Seniors' Timely Access to Care Act: Aims to streamline prior auth for Medicare Advantage plans with electronic processing and real-time decisions for routine services.

How to Speed Up Prior Authorization: Practical Tips

Before the Request

• Ask your doctor's office if prior auth is needed BEFORE your appointment. Don't find out after you've already been scheduled for a procedure.
• Call your insurance company directly and ask: "Does procedure code [X] require prior authorization under my plan?" Get the representative's name and reference number.
• Choose in-network providers. Out-of-network services almost always need prior auth and are more likely to be denied. Use Taven's provider comparison tool to find in-network options near you.

During the Process

• Follow up every 2–3 days. Don't assume the process is moving along. Call the insurance company and your doctor's office to check the status.
• Ask if your doctor marked it as urgent. If your condition could worsen with delays, your doctor should submit an expedited request.
• Keep records of everything. Note the date of every call, who you spoke with, and what they said. If it ever goes to appeal, this documentation is gold.

If It's Taking Too Long

• File a complaint with your state's insurance commissioner. Insurers are regulated at the state level, and regulators take consumer complaints seriously. You can usually file online in minutes.
• Ask your doctor to escalate. A peer-to-peer review request can sometimes shake things loose when a request has been sitting in limbo.
• Contact your employer's HR department (for employer-sponsored plans). HR has a direct relationship with the insurer and can sometimes expedite reviews.

Prior Authorization vs. Predetermination vs. Referral

These terms get confused constantly. Here's the difference:

• Prior authorization: Required approval BEFORE a service. If you skip it, the insurer can refuse to pay.
• Predetermination (pre-estimate): An optional request to find out how much the insurer will pay. It's informational — not a guarantee and not required. Think of it like getting a cost estimate before a car repair.
• Referral: An order from your primary care doctor to see a specialist. Some HMO plans require referrals; PPOs usually don't. A referral is NOT the same as prior auth — you might need both.

What Happens If You Skip Prior Authorization?

This is the scary part. If a service requires prior auth and you (or your doctor) don't get it:

• Your insurance may refuse to pay entirely. You'd be responsible for the full cost.
• Some plans reduce coverage instead of eliminating it — for example, paying 50% instead of 80%.
• Retroactive (after-the-fact) authorization is sometimes possible, but it's harder to get and not guaranteed.

Key takeaway: Always confirm prior auth status before proceeding with any non-emergency service. A 5-minute phone call can save you thousands of dollars.

The Bottom Line

Prior authorization is a gatekeeper system that — love it or hate it — you need to navigate. Here's your cheat sheet:

• ✅ Prior auth = insurance pre-approval before a service is provided
• ✅ Your doctor's office handles it, but you should follow up
• ✅ Timelines range from 24 hours to 15+ days — ask if urgent processing is appropriate
• ✅ Denials aren't final — appeal, and your odds are good
• ✅ Never skip prior auth for non-emergency services — you could get stuck with the full bill
• ✅ Keep records of every call, every date, every name

The system is slowly improving, with new rules requiring faster electronic processing and more transparency. But until then, being your own advocate — or having someone in your corner — is the best way to avoid delays and denials.

Need help understanding your costs before committing to a procedure? Compare care costs on Taven to see what you should expect to pay in your area.