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. According to a 2024 American Medical Association survey, 94% of physicians reported that prior authorization caused delays in patient care, and 33% said it had led to a serious adverse event for a patient. 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, and how to navigate it effectively. 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. Here is the basic process. 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 the medical necessity of the service — diagnosis codes, test results, treatment history, and sometimes peer-reviewed 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 organizations like 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.
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 the decision, submit additional documentation, or suggest an alternative treatment the insurer will cover. The entire process can take anywhere from 24 hours for urgent requests to 15 business days or more for non-urgent ones.
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. Common services that frequently require prior auth include advanced imaging (MRI, CT scan, PET scan), 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, outpatient procedures (colonoscopy, endoscopy in some plans), physical therapy beyond a set number of visits, and mental health and substance abuse treatment.
The specific services requiring prior auth vary by insurer and plan. Your plan’s summary of benefits or evidence of coverage document lists prior authorization requirements. Many insurers also maintain searchable databases on their websites where you can check whether a specific procedure code requires pre-approval. When in doubt, call the number on the back of your insurance card and ask before scheduling a service — getting care without required prior auth can result in the claim being denied entirely, leaving you responsible for the full cost.
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 prevents unnecessary procedures, encourages use of less expensive but equally effective alternatives (such as generic medications before brand-name drugs), and reduces waste in the healthcare system. The America’s Health Insurance Plans (AHIP), the insurance industry’s lobbying group, has cited studies suggesting prior authorization saves the healthcare system billions of dollars annually.
Critics — including the AMA, the American Hospital Association, and patient advocacy groups — counter that prior authorization has grown far beyond its original intent. What started as a check on a small number of expensive or risky procedures has expanded to cover routine care, creating an administrative burden that consumes an estimated 34 hours of physician time per week per practice, according to the AMA. Physicians report that prior auth requirements often seem to prioritize cost over clinical judgment, forcing doctors to prescribe second- or third-choice treatments because the insurer will not approve the first-line option without a lengthy appeals process.
The reality is 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 regulations set some boundaries on prior authorization timelines, but they vary. For Medicare Advantage plans, CMS requires decisions within 72 hours for urgent requests and 7 calendar days for standard requests (with a possible 14-day extension if more information is needed). Starting in 2026, new CMS rules will require Medicare Advantage and Medicaid managed care plans to process standard prior auth requests within 7 days and urgent requests within 72 hours, with electronic submission capabilities.
For commercial (employer-sponsored and individual) plans, state laws govern timelines. Most states require urgent prior auth decisions within 24 to 72 hours. Non-urgent decisions typically must be made within 5 to 15 business days, though some states allow up to 30 days. If the insurer does not respond within the required timeframe, some states have “deemed approved” provisions — the request is automatically approved if the insurer fails to meet the deadline.
In practice, many prior authorization requests take longer than these timelines suggest, particularly when the insurer requests additional information (which resets the clock in some cases). A 2024 AMA survey found that the average prior authorization takes approximately 12 days to resolve, and one in three are initially denied — though most denials are eventually overturned on appeal.
What to Do If Your Prior Authorization Is Denied
A denial is not the end of the road. According to CMS data on Medicare Advantage plans, roughly 75% of prior authorization denials that are appealed are eventually overturned — suggesting many initial denials are inappropriate. Here is how to respond.
First, understand the reason for the denial. The insurer is required to send you (and your doctor) a written explanation. Common denial reasons include: the service is 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 or insufficient. Knowing the specific reason guides your next step.
Your doctor’s office can submit a peer-to-peer review — a conversation between your doctor and the insurer’s medical director — to argue the clinical case directly. This is often the most effective first step for overturning a denial. If the peer-to-peer fails, you have the right to file a formal internal appeal. Under ACA regulations, insurers must complete internal appeals within 30 days for non-urgent 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 process required by federal law for all non-grandfathered plans.
Throughout this process, 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. Patient advocacy is not optional in the prior authorization process — it is essential.
Prior Authorization Reform Efforts
Growing bipartisan frustration with prior authorization has produced legislative action at both the federal and state levels. The CMS Interoperability and Prior Authorization Final Rule (CMS-0057-F), finalized in 2024, requires Medicare Advantage, Medicaid managed care, and marketplace plans to implement electronic prior authorization by 2026, respond to standard requests within 7 days (down from 14), and provide specific denial reasons tied to clinical criteria.
At the state level, more than 30 states have enacted or proposed prior authorization reform laws. Common provisions include gold carding — exempting physicians with high approval rates (typically 90%+) from prior auth requirements for specific services, requiring insurers to honor prior authorizations for a minimum period (often 90 days) when a patient switches plans, and mandating real-time electronic prior auth submission and response. The AMA has pushed for federal legislation requiring insurers to streamline prior auth, improve transparency, and protect continuity of care during appeals.
These reforms are meaningful but incomplete. The fundamental 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 number of services, including certain durable medical equipment and some outpatient procedures. Medicare Advantage plans, which are run by private insurers, frequently require prior authorization for a broader range of services — similar to commercial insurance. 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 is typically responsible for initiating and managing the prior authorization process. However, you share responsibility for ensuring it gets done. Before scheduling a procedure, confirm with your doctor’s office that they have submitted the prior auth and received approval. Do not assume it has been handled — a lapse can result in a claim denial that 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. Insurers cannot deny emergency claims solely because prior authorization was not obtained. However, once you are stabilized, subsequent non-emergency care (such as a planned surgery following an ER visit) may still require prior auth.
How long does a prior authorization approval last?
It varies by insurer and service. Most prior authorizations are valid for 60 to 90 days. Some are valid for a specific number of visits (such as 12 physical therapy sessions over 90 days). If your treatment is delayed beyond the approval window, you may need to request a new authorization. Check the approval letter for the specific expiration date.
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 appeal if warranted. The data shows 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.