Reasons for Prior Authorization Denials & How To Reduce Denial Rates

The prior authorization (PA) process has become an essential yet challenging aspect of patient care. It’s a task that requires meticulous attention to detail. It takes a deep understanding of insurance policies, and the ability to navigate a maze of documentation requirements. For many medical practices, the PA process can be a real-time suck. According to a 2024 American Medical Association (AMA) survey, 92% of physicians reported that the number of prior authorization requirements had increased in the past five years. The significant drain on time and resources leads to inefficiencies, impact on revenue, and, in some cases, patient care delays. Optimizing your prior authorization process for where denials happen the most can ensure timely approvals and allow healthcare providers to focus on their primary mission—caring for patients. 
This article will discuss prior authorization denials and why a prior authorization may be denied. It will also provide some logical improvements or considerations for medical practices to level up their prior authorization workflow.

Reason for Prior Authorization Denials

Insurance companies require prior authorization to approve certain medical procedures, tests, or medications before they are administered to patients. This step ensures that the proposed treatment is medically necessary and covered under the patient’s insurance plan. While the concept sounds straightforward, the reality is often far more complex and frustrating.
The reasons for prior authorization denials are varied, ranging from incomplete or incorrect information to non-compliance with payer policies. Want a deeper dive into prior authorizations? Here is more about how prior authorizations work.  According to general consensus, some of the most common prior authorization denial reasons include:

• Incomplete or Incorrect Information
• Lack of Prior Authorization Request
• Administrative Errors
• Duplicate Requests
• Out-of-Network Provider
• Plan Coverage Limits
• Non-Formulary Medications
• Lack of Medical Necessity
• Non-Compliance with Payer Policies
• Pre-existing Condition Exclusion

Sound familiar? Let’s take it a step further.

DataMatrix has analyzed thousands of authorizations performed in the first half of 2024. We have identified the following as the top reasons for prior authorization denials among its 300+ medical practices:

List of the five reasons from the DataMatrix Medical research 👇🏼

1. Lack of Medical Necessity
2. Incomplete or Incorrect Information
3. Lack of Prior Authorization Request
4. Duplicate Requests
5. Non-Formulary Medications

Are any of these surprising as reasons why a prior authorization would be denied?
Let’s talk more about these five reasons for prior authorization denials.

Medical Necessity Documentation

Based on the research, the lack of medical necessity was the top reason for a denial. Insurance companies require thorough documentation to justify the necessity of a proposed treatment. This typically includes a comprehensive packet of medical records from the past six months.  Requirements should also include the most recent clinical notes. Plus the diagnostic tests, and evidence of conservative treatments attempted before recommending more invasive procedures such as surgery or advanced imaging.
Medical practices often struggle to gather and submit all the required documentation, leading to delays or outright denials.

Consider the following to reduce prior authorization denials by improving medical necessity documentation:

• Standardize Documentation Procedures: Implement standardized templates and checklists to ensure all necessary patient information is consistently recorded, reducing the risk of denials due to incomplete documentation.
• Educate and Train Staff Regularly: Provide ongoing training on payer guidelines and documentation best practices to ensure staff accurately and thoroughly document medical necessity.
• Conduct Internal Audits: Regularly audit documentation to identify and correct gaps, ensuring all necessary details are included before submission.
• Leverage Technology for Documentation Management: Use EHR systems to streamline and automate documentation, helping to ensure completeness and accuracy in submissions. You could also consider a all encompassing prior authorization services to increase efficiencies. 

Real-Life Example: Orthopedic Practice Reduces Denials by Standardizing Documentation

In early 2025, an orthopedic group in Florida faced repeated prior authorization denials for MRI requests. The insurer cited “insufficient proof of medical necessity,” despite the provider believing documentation was complete.

After review, DataMatrix Medical discovered that the clinical notes often omitted details on prior conservative treatments, physical therapy attempts, and medication trials that insurers required before approving advanced imaging. Additionally, diagnostic tests from outside facilities weren’t consistently included in the submission packet.

To resolve this, DataMatrix implemented a standardized documentation checklist across all providers in the group. Each request packet now automatically includes:

• The last six months of clinical notes

• Conservative treatment evidence (e.g., PT logs, medication history)

• Diagnostic imaging reports and test results

• A summary of patient progression

Within 60 days, the practice saw a 72% reduction in MRI-related denials and cut average turnaround time from 10 days to 3.

Combining staff retraining, audit checks, and EHR-integrated templates, the group turned one of its most costly administrative pain points into a reliable, efficient process.

Incomplete or Incorrect Information

Another primary reason for a prior authorization denial is incomplete or incorrect information. This can be any of the following:

1. Missing Patient Information: A prior authorization request is denied because the patient’s demographic details, such as date of birth or insurance ID number, were not included or were entered incorrectly.
2. Incorrect CPT/ICD Codes: The request is denied because the procedure code (CPT) or diagnosis code (ICD-10) provided does not match the authorized treatment or diagnosis, leading the insurer to reject the submission.
3. Incomplete Medical History: A denial occurs because the documentation needs a complete medical history or recent clinical notes demonstrating the medical necessity of the requested treatment.
4. Inaccurate Provider Information: The request is denied because the provider’s National Provider Identifier (NPI) or tax identification number (TIN) was entered incorrectly, preventing the insurance company from validating the provider.

Consider the following to reduce prior authorization denials by improving incomplete or incorrect information:

• Implement a Double-Check System: Establish a process whereby a second team member reviews all prior authorization requests before submission, ensuring all required information is complete and accurate.
• Use Technology for Validation: Leverage EHR systems or specialized software that can automatically validate essential information, such as CPT/ICD-10 codes and patient demographics, reducing the likelihood of errors.
• Maintain Up-to-Date Templates: Regularly update and utilize standardized templates that include all necessary fields and reminders for critical information, helping to prevent omissions or incorrect entries during the PA process.

Lack of Prior Authorization Requests/Duplicate Requests

Let’s combine these two reasons because the problems they create are similar. Lack of prior authorization requests/duplicate requests creates denials because it creates confusion and disrupts the authorization process. Insurance companies may (more often than not) only cover the procedure or medication with prior authorization. Similarly, duplicate requests can cause delays as insurers may need to verify whether the request is new or a repeat of an already approved or denied request, often resulting in unnecessary denials or additional administrative work to resolve the issue.

Consider the following to reduce prior authorization denials by improving the lack of prior authorization requests/duplicate requests:

• Create a Centralized Tracking System: Implement a centralized system to track all prior authorization requests, ensuring that each request is logged, monitored, and updated in real-time to avoid missed or duplicate submissions.
• Set Clear Workflow Protocols: Establish clear protocols for when and how prior authorization requests should be initiated, including who is responsible, to ensure that all requests are noticed and correctly duplicated.
• Regularly Train Staff on PA Procedures: Conduct regular training sessions to ensure all team members understand the importance of obtaining prior authorizations and know the processes to avoid duplicate submissions.

Non-Formulary Medications

Of our top five list, we see that non-formulary medications lead to many prior authorization denials. Often, medications are not included in the insurance company’s approved list of covered drugs. When a prescribed medication is non-formulary, the insurer may deny the request.  Insurers may also require additional justification or an alternative medication to be considered. There is so much more reated to pain medicine prior autorizations. 

Consider the following to reduce prior authorization denials by improving based on non-formulary medications:

• Check Formulary Lists Before Prescribing: Always review the patient’s insurance formulary list before prescribing medications to ensure the chosen drug is covered, reducing the likelihood of denials.
• Provide Clear Justification: If a non-formulary medication is necessary, submit a detailed explanation of why it’s required over formulary alternatives, including relevant clinical evidence, to strengthen the prior authorization request.
• Have a Backup Plan: Identify and discuss formulary alternatives with the patient and provider in advance so a backup prescription can be quickly submitted if the non-formulary request is denied.

Conclusion

The prior authorization in medical billing is a necessary but often cumbersome aspect of modern healthcare. It takes a lot of time and causes financial challenges in many medical practices. The Healthcare Financial Management Association (HFMA) reported that denial rates for prior authorizations averaged around 12%, with an estimated revenue loss of up to $5 billion annually across the healthcare industry. This is why optimizing your processes to reduce denials is more important than ever.

The complexities of gathering documentation, adhering to insurance policies, and navigating the submission process can be overwhelming. It’s about taking it on in small steps. Implement or improve at least one of the top reasons for denials each month or quarter, you are sure to see improvement.