What Is Prior Authorization in Health Insurance?

Healthcare Policy · By Web Admin · · Updated · 11 min read
What Is Prior Authorization in Health Insurance?

Your doctor recommends an MRI, a new medication, or a surgical procedure — and then tells you the insurance company needs to approve it first. That approval process is called prior authorization, and it is one of the most frustrating aspects of the American healthcare system for both patients and physicians. What is prior authorization? It is a requirement by your health insurer that your doctor obtain approval before a specific treatment, medication, or procedure is covered. The insurer reviews whether the service is medically necessary and appropriate before agreeing to pay for it. In the American Medical Association’s annual physician surveys, large majorities of doctors report that prior authorization delays patient care, and a substantial share say it has led to a serious adverse event for a patient — findings the AMA has documented consistently in recent years. Whether you are dealing with a prior auth now or want to understand the process before you need it, this guide covers how it works, why it exists, how to fight a denial, and what is changing in 2026 and 2027. This is general educational information, not legal or insurance advice. For more on healthcare costs and insurance, see our healthcare costs guide.

How Prior Authorization Works

Prior authorization — also called pre-authorization, pre-approval, or pre-certification — is a utilization-management tool used by health insurers. The basic process works like this. Your doctor determines you need a specific medication, procedure, test, or referral. Before providing or prescribing the service, your doctor’s office submits a prior authorization request to your insurer. The request includes clinical documentation supporting medical necessity — diagnosis codes, test results, treatment history, and sometimes references to clinical guidelines or literature.

The insurer’s utilization-review team — which may include nurses, pharmacists, and physician reviewers — evaluates the request against the plan’s clinical criteria. These criteria are often based on evidence-based guidelines from bodies such as the Agency for Healthcare Research and Quality (AHRQ) or specialty medical societies, though each insurer sets its own specific policies. The insurer then approves, denies, or requests additional information.

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If approved, the service can proceed and will be covered under the terms of your plan (subject to your deductible, copay, and coinsurance). If denied, your doctor can appeal, submit additional documentation, or suggest an alternative treatment the insurer will cover. The process can take anywhere from a day or so for urgent requests to a couple of weeks or more for non-urgent ones, and requesting more information can extend it further.

What Requires Prior Authorization?

Not every medical service needs prior authorization, but the list of services that do has expanded significantly over the past decade. Services that frequently require prior auth include advanced imaging (MRI, CT, PET), specialty medications (particularly biologics, cancer drugs, and high-cost injectables), non-emergency surgeries (joint replacements, spinal procedures, bariatric surgery), durable medical equipment (power wheelchairs, CPAP machines, prosthetics), inpatient hospital admissions, some outpatient procedures, physical therapy beyond a set number of visits, and certain mental health and substance-use treatments.

The specific services requiring prior auth vary by insurer and plan. Your plan’s summary of benefits or evidence of coverage lists the requirements, and many insurers maintain searchable databases where you can check whether a specific procedure code needs pre-approval. When in doubt, call the number on the back of your insurance card and ask before scheduling — getting care without a required prior auth can result in the claim being denied entirely, leaving you responsible for the full cost. This is closely related to how much you owe after approval; our explainer on 50% coinsurance after the deductible covers that side of the bill.

Why Insurers Require Prior Authorization

Insurers argue that prior authorization serves two purposes: controlling costs and ensuring clinical appropriateness. From the insurer’s perspective, it aims to prevent unnecessary procedures, encourage less expensive but equally effective alternatives (such as generic medications before brand-name drugs), and reduce waste. Industry groups such as America’s Health Insurance Plans (AHIP) have cited estimates that prior authorization saves the healthcare system money.

Critics — including the AMA, the American Hospital Association, and patient-advocacy groups — counter that prior authorization has grown far beyond its original intent. What began as a check on a small number of expensive or risky procedures now covers a great deal of routine care, creating an administrative burden. The AMA has reported that physicians and their staff spend many hours each week completing prior authorizations — on the order of a dozen or more hours per physician — and that requirements can push doctors toward second- or third-choice treatments because the first-line option is not approved without a lengthy appeal.

The reality sits somewhere in the middle. Some prior authorization requirements genuinely protect patients by ensuring appropriate care; others create harmful delays. The challenge is distinguishing between the two — and reforming the process so it serves patients rather than just the insurer’s bottom line.

Timelines: How Long Does Prior Authorization Take?

Federal and state rules set some boundaries on prior authorization timelines, but they vary by plan type. A significant change took effect for many government-related plans in 2026. Under the CMS Interoperability and Prior Authorization Final Rule (CMS-0057-F), finalized in 2024, affected payers — Medicare Advantage, most Medicaid and CHIP programs, and qualified health plans on the federal Marketplace — must, as of 2026, send prior authorization decisions within 72 hours for expedited (urgent) requests and seven calendar days for standard requests. That standard-request window is a tightening from the prior 14-day standard for Medicare Advantage. (These timeframe requirements apply to medical services; the rule does not cover prescription-drug prior authorizations handled under Part D.)

For fully commercial (employer-sponsored and individual) plans not covered by that federal rule, state laws govern timelines. Many states require urgent decisions within roughly 24 to 72 hours and non-urgent decisions within about 5 to 15 business days, though some allow longer. A number of states also have “deemed approved” provisions, under which a request is automatically approved if the insurer misses the deadline. Because these rules differ by state and plan, confirm the specifics that apply to your coverage.

In practice, requests can take longer than the headline timelines suggest, particularly when the insurer asks for more information, which can pause the clock. AMA survey data have found that prior authorizations often take days to resolve and that a meaningful share are initially denied — though most denials are overturned on appeal, which is why persistence matters.

What to Do If Your Prior Authorization Is Denied

A denial is not the end of the road. CMS data on Medicare Advantage plans have shown that a large majority of appealed prior-authorization denials are eventually overturned — suggesting many initial denials are inappropriate or simply reflect missing documentation. Here is how to respond.

First, understand the reason for the denial. The insurer must send you (and your doctor) a written explanation, and the CMS rule now requires affected plans to give specific reasons tied to clinical criteria. Common reasons include: the service was not considered medically necessary, the plan requires you to try a less expensive alternative first (step therapy), the requested provider is out of network, or documentation was incomplete. The specific reason guides your next step.

Request a peer-to-peer review. Your doctor’s office can request a peer-to-peer — a direct conversation between your doctor and the insurer’s medical director — to argue the clinical case. This is often the most effective first step for overturning a denial.

File a formal appeal. If the peer-to-peer fails, you have the right to a formal internal appeal. Under Affordable Care Act rules for non-grandfathered plans, insurers generally must complete internal appeals within 30 days for non-urgent (pre-service) cases and 72 hours for urgent cases. If the internal appeal is denied, you can request an external review by an independent third party — a right guaranteed by federal law for non-grandfathered plans (employer plans governed by ERISA have parallel appeal protections). Medicare and Medicaid have their own multi-level appeal processes.

Document everything. Keep copies of all correspondence, note the names and titles of people you speak with, and record dates and times of calls. If your doctor’s office is handling the appeal, stay in contact and ask for status updates. In prior authorization, patient advocacy is not optional — it is often what gets care approved.

Prior Authorization Reform: What Is Changing in 2026 and Beyond

Growing bipartisan frustration with prior authorization has produced action at the federal and state levels, and several changes are phasing in around 2026 and 2027.

The CMS final rule (CMS-0057-F). Finalized in 2024, this rule applies to Medicare Advantage, most Medicaid and CHIP plans, and Marketplace qualified health plans. Its operational provisions — the faster decision timelines described above, a requirement to provide specific denial reasons, and public reporting of prior-authorization metrics — generally took effect in 2026. Its technology provisions require affected payers to build electronic prior-authorization capabilities, including a Prior Authorization API (built on the FHIR data standard) and related Provider Access and Payer-to-Payer APIs, by January 1, 2027. The goal is to move prior auth out of fax machines and phone calls and into automated, electronic exchange — which supporters expect to speed decisions and reduce paperwork, though the real-world impact will depend on implementation. Timelines and details can shift, so treat specific dates as current guidance rather than a guarantee.

State reforms. Many states have enacted or proposed prior-authorization reform laws. Common provisions include gold carding — exempting physicians with consistently high approval rates from prior-auth requirements for specific services — requiring insurers to honor an existing prior authorization for a minimum period (often around 90 days) when a patient switches plans, reforming step therapy so patients can seek exceptions more easily, and mandating faster or real-time electronic submission and response. Because these laws are state-specific and evolving, check what applies where you live.

Voluntary industry commitments. Under pressure from regulators, clinicians, and patients, major insurers announced voluntary commitments in 2025 to streamline prior authorization — including reducing the volume of services subject to it, standardizing electronic submissions, honoring existing authorizations during plan transitions, and expanding real-time decisions. These are pledges rather than binding rules, so their impact will become clear only as they are carried out, and patients should not assume any particular service is exempt without confirming.

These reforms are meaningful but incomplete. The underlying tension between insurer cost control and clinical autonomy is unlikely to be fully resolved by regulation alone. As a patient, understanding the process and being willing to advocate for yourself remains the most reliable strategy.

Frequently Asked Questions

Does Medicare require prior authorization?

Original Medicare (Parts A and B) requires prior authorization for a limited set of services, including certain durable medical equipment and some outpatient procedures. Medicare Advantage plans, run by private insurers, frequently require prior authorization for a broader range of services — similar to commercial insurance — though the 2026 CMS timelines now apply to them. Part D prescription-drug plans also use prior auth for some medications.

Who is responsible for getting prior authorization — me or my doctor?

Your doctor’s office typically initiates and manages the prior authorization, but you share responsibility for making sure it gets done. Before scheduling a procedure, confirm with the office that the prior auth was submitted and approved. Do not assume it has been handled — a lapse can lead to a denied claim you are stuck paying.

Can I get emergency care without prior authorization?

Yes. Federal law (the Emergency Medical Treatment and Labor Act, or EMTALA) requires emergency rooms to stabilize and treat you regardless of insurance or prior-authorization status, and insurers cannot deny emergency claims solely because prior auth was not obtained. Once you are stabilized, however, subsequent non-emergency care (such as a planned follow-up surgery) may still require prior auth.

How long does a prior authorization approval last?

It varies by insurer and service. Many prior authorizations are valid for a defined window (often around 60 to 90 days) or for a specific number of visits (such as a set number of physical-therapy sessions). If your treatment is delayed beyond the approval window, you may need a new authorization. Check the approval letter for the specific expiration date.

What is step therapy, and can I get around it?

Step therapy (“fail first”) requires you to try one or more preferred, usually less expensive, treatments before the plan covers the one your doctor originally recommended. If a required step is inappropriate for you — for example, you have already tried it or have a contraindication — your doctor can usually request a step-therapy exception with supporting documentation, and many states have laws making exceptions easier to obtain.

What to Do Next

Prior authorization is not going away, but understanding the process gives you power within it. Before any non-emergency procedure, test, or new medication, ask your doctor’s office: “Does this require prior authorization, and has it been submitted?” Follow up with your insurer to confirm approval before the service date. If a request is denied, do not accept the denial at face value — ask for the specific reason, request a peer-to-peer review, and file an internal and, if needed, external appeal. The data show that persistence pays off, with most appealed denials eventually overturned. Stay organized, stay informed, and do not let an administrative process stand between you and the care your doctor recommends.

TL;DR

Prior authorization is your insurer’s requirement that certain services, medications, or procedures be approved before they are covered. It is meant to control cost and check appropriateness, but it has expanded to routine care and is a leading cause of care delays. If you are denied, understand the reason, request a peer-to-peer review, and use your internal and external appeal rights — most appealed denials are overturned. Under the 2024 CMS final rule, affected plans face faster decision timelines starting in 2026 (72 hours urgent, 7 days standard) and must build electronic prior-auth APIs by 2027; state gold-carding and step-therapy reforms plus 2025 voluntary industry pledges are also in motion. Always confirm the specifics with your own plan.

This article is general educational information, not legal, medical, or insurance advice. Coverage rules and reform timelines vary by plan and can change; verify details with your insurer and your state’s regulator.

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