Common prior authorization mistakes cost practices time, money, and patient trust. Providers complete about 40 prior authorizations per week on average, and even a 5% error rate can mean hundreds of reworked requests each year for a small practice. This guide breaks down the seven most common prior authorization mistakes — from incomplete clinical notes to missed deadlines — and shares practical strategies to help you reduce denials, speed up approvals, and protect your patients' care.

On average, practices complete 40 prior authorizations per provider per week, according to a recent survey. For a small two-provider practice, that’s 86 prior authorizations weekly and a total of 4,472 annually. To put that in perspective, if a two-provider practice experienced:

Even in a small practice, hundreds of prior authorizations may require additional staff time each year if documentation, coding, or payer-specific requirements are missed. It’s important to identify common prior authorization mistakes and discover how accurate clinical notes, ICD-10 and Current Procedural Terminology (CPT) coding, and payer compliance can streamline approvals and protect patient care.

The most common prior authorization mistakes include submitting incomplete clinical documentation, failing to adequately demonstrate medical necessity, using incorrect or mismatched diagnosis and procedure codes, and omitting required supporting records such as imaging reports or prior treatment histories.

Practices also frequently submit requests using outdated payer forms, request authorization for the wrong service, overlook payer-specific requirements, or allow authorizations to expire before services are rendered. Common mistakes such as missing deadlines, entering inaccurate patient or insurance information, and failing to respond to payer requests for additional information can also result in denials or treatment delays. 

Even small common prior authorization mistakes can lead to unnecessary rework, delayed patient care, and lost reimbursement. Prior authorization errors often prevent payers from determining whether a service meets coverage requirements, resulting in requests for additional information, delayed decisions, or outright denials for various reasons.

Missing documentation, coding inaccuracies, incomplete clinical details, and failure to satisfy payer-specific requirements typically require practices to resubmit requests or file appeals, adding days or even weeks to the approval process. Delays due to prior authorization errors can postpone diagnostic tests, procedures, medications, and other medically necessary care, while increasing administrative workload and costs. 

For patients, the consequences of prior authorization mistakes may include:

Clinical notes that omit the patient’s symptoms, severity of illness, functional limitations, previous treatments, treatment response, or clinical rationale often prompt requests for additional documentation or force reviewers to deny the request due to insufficient evidence. In addition, generic or copied-and-pasted documentation can also make it difficult for payers to understand why a specific test, procedure, medication, or specialist referral is appropriate for the individual patient.

Here’s how this plays out in practice:

A primary care provider requests prior authorization for an MRI of the lumbar spine for a patient with chronic low back pain. The clinical note simply states, ‘Patient has back pain. MRI requested.’ It does not document the patient’s symptoms (e.g., radiating leg pain or numbness), severity, functional limitations, duration of symptoms, previous treatments such as physical therapy or anti-inflammatory medications, or why advanced imaging is now clinically necessary. Because the documentation lacks the information needed to demonstrate medical necessity, the payer requests additional records or denies the authorization until more detailed clinical documentation is submitted.

If the ICD-10 diagnosis code does not accurately reflect the patient’s condition, lacks the required level of specificity (e.g., laterality, disease stage, or encounter type), or does not align with the requested procedure or medication, the insurance company may be unable to verify medical necessity. Coding mismatches between the diagnosis, provider documentation, and CPT or HCPCS procedure codes can also trigger denials or requests for additional information. Even minor coding errors—such as using an unspecified diagnosis when a more specific code is supported by the clinical record—can delay approval and require staff to correct and resubmit the request.

For example:

An orthopedic surgeon requests an MRI for a patient with persistent right shoulder pain after six weeks of failed conservative treatment. The prior authorization is submitted with the ICD-10 code M25.519 (Pain in unspecified shoulder) instead of the more specific M25.511 (Pain in right shoulder) or a diagnosis that better reflects the suspected condition, such as a rotator cuff tear. Because the diagnosis code lacks specificity and doesn’t clearly support the medical necessity criteria for advanced imaging, the payer requests additional documentation or denies the authorization pending clarification, delaying the patient’s MRI.

When addressing common prior authorization mistakes, keep in mind that a service that is approved by one payer may require different supporting documentation, additional clinical evidence, or step therapy under another. Practices may inadvertently use the wrong authorization form, omit required test results or treatment histories, request approval through the wrong portal, or overlook payer-specific timeframes and renewal requirements.

Consider this scenario:

A neurologist requests prior authorization for a migraine preventive medication. The payer’s policy requires patients to first try and fail two preferred lower-cost medications before covering the requested drug. Because the authorization request does not document the patient’s previous medication trials and treatment outcomes, the payer denies the request based on its step therapy policy, even though the medication may be clinically appropriate.

Depending on the service, missing supporting documentation may include progress notes, laboratory results, imaging reports, pathology findings, operative reports, specialist consultations, medication histories, or documentation of failed conservative treatments. When these records are omitted or incomplete, payers typically cannot verify that the requested service meets their coverage criteria and may request additional information or deny the authorization outright.

Here’s a common version of this mistake:

A rheumatologist requests prior authorization for a biologic medication to treat severe rheumatoid arthritis. The payer requires documentation of disease activity, laboratory results, and evidence that the patient previously tried and failed conventional disease-modifying antirheumatic drugs. Because the prior authorization request does not include the patient’s treatment history or recent laboratory reports, the payer places the request on hold until the missing records are submitted.

Simply documenting a diagnosis is often insufficient. Payers typically expect evidence that the patient’s symptoms, severity of illness, functional limitations, clinical findings, previous treatments, and treatment response support the requested test, procedure, medication, or referral.

For instance:

A pain management provider requests prior authorization for a lumbar epidural steroid injection for a patient with chronic low back pain. The clinical note documents the diagnosis but does not describe the patient’s worsening symptoms, functional limitations, imaging findings, or failure to improve after physical therapy and anti-inflammatory medications. Because the request does not clearly establish why the injection is medically necessary at this stage of treatment, the payer denies the authorization pending additional clinical documentation.

Many payers require authorization before a medication is dispensed, a procedure is performed, or advanced imaging is obtained, and some impose strict deadlines for submitting requests or renewing existing authorizations. Delays often occur when practices wait until just before the scheduled service, fail to recognize that prior authorization is required, or do not allow enough time to gather the necessary clinical documentation. In some cases, an authorization may expire before the patient receives care, requiring the practice to repeat the approval process.

Here’s how this can unfold:

A gastroenterology practice schedules a patient for a screening colonoscopy the following week but does not submit the prior authorization request until two days before the procedure. Because the payer’s review process typically takes five business days and requires additional clinical documentation, the authorization is not approved in time. The procedure must be postponed, creating scheduling challenges for the practice and delaying the patient’s care.

Common prior authorization mistakes include missing attachments, incorrect patient or insurance information, mismatched diagnosis and procedure codes, incomplete clinical notes, or unanswered fields on the authorization form.

A quick example:

A cardiology practice submits a prior authorization request for a cardiac CT scan. The provider’s documentation supports the request, but the authorization packet is missing the patient’s recent stress test results and includes an outdated insurance member ID. The payer cannot process the request until the missing information is corrected and resubmitted, delaying approval and forcing the patient’s appointment to be rescheduled.

Prior authorization will likely remain a routine part of healthcare delivery, but practices can reduce delays, administrative burden, and avoidable denials by standardizing workflows and improving communication. These five strategies to address common prior authorization mistakes can help simplify the process while improving efficiency for both staff and patients.

Reducing common prior authorization mistakes starts with consistent processes, accurate documentation, and proactive communication. Use this checklist to help improve first-pass approval rates and minimize avoidable delays and denials.

For a broader look at reducing manual bottlenecks, see these tips on improving your medical billing workflow.