A “not medically necessary” or “experimental/investigational (E/I)” decision can be frustrating, especially when a provider believes an innovative medical device is appropriate for the patient. A medical insurance denial may reflect documentation, payer policy, coding, or a technology-level coverage classification.
This article explains what a medical necessity or E/I denial means, the common reasons behind these denials, what denial codes may show on an EOB, and how medical device manufacturers can respond more strategically.
What “not medically necessary” and “E/I” actually mean, and what they don’t
“Not medically necessary” is a payer’s determination that a service, procedure, or device does not meet its coverage criteria for the patient’s documented condition.
It does not necessarily mean the treatment does not work. It also does not automatically mean the physician’s clinical judgment was flawed. In many cases, the issue is whether the submission clearly demonstrates that the patient meets the payer’s specific criteria.
A medical necessity denial differs from an experimental/investigational determination. “Experimental/investigational” generally means the payer has classified the technology as unproven or lacking sufficient evidence, regardless of the individual patient’s clinical picture.
A technology can be FDA-cleared or FDA-approved and still receive an experimental/investigational coverage denial. FDA authorization and payer coverage are separate decisions. The FDA evaluates devices within its regulatory purview, while payers independently decide whether and under what circumstances to cover and reimburse a technology.fda+1
A policy decision, not a clinical one
Many medical necessity denials are policy decisions expressed in clinical terms.
A clinical decision considers the patient’s history, comorbidities, prior treatments, physician judgment, and relevant evidence. A payer policy decision applies predetermined coverage criteria to the documentation submitted with the request or claim.
When a claim is denied as not medically necessary, the reviewer may be determining whether the documentation matches a checklist or published coverage policy. The payer may not be independently reassessing the treating physician’s clinical judgment.
That distinction matters when planning a medical necessity appeal. If the problem is incomplete documentation, more patient-specific information may help. If the barrier is a broader payer policy, the response may also need to address the policy’s evidence base and relevance to the technology.
Why innovative medical devices are especially vulnerable to this denial type
Innovative medical devices can be vulnerable to this type of insurance denial for several reasons. Payer policies, coding systems, and coverage pathways may not move at the same speed as clinical evidence and technology adoption.
A newer device may not have a payer-specific policy, established coding pathway, or enough payer claims history for reviewers to apply familiar criteria. In those circumstances, a request may be evaluated under an analogous policy, generic investigational language, or reviewer discretion.
This does not mean the technology is ineffective. It can mean the payer’s policy infrastructure has not yet caught up to the device, indication, or evidence base.
Common medical necessity denial reasons
Medical necessity denial reasons vary by payer, plan, technology, and patient. Reviewing the denial notice, EOB, applicable payer policy, and supporting claim documentation is essential before responding.
No established payer coverage policy for the technology
Some payers do not have a dedicated coverage policy for a newer device or indication. Without one, the payer may apply a general policy, compare the technology to an unrelated procedure, or use broad investigational criteria.
In these cases, the response may need to explain the technology, intended use, relevant evidence, and how the individual patient fits a reasonable medical necessity framework.
Useful support can include peer-reviewed studies, specialty-society guidance, FDA labeling, and comparable coverage determinations. Medicare coverage policies may include National Coverage Determinations and Local Coverage Determinations, depending on the service and setting.med.noridianmedicare
Insufficient medical necessity documentation in the submission
A denial may occur when the submitted record does not clearly show that the patient meets the payer’s criteria. The documentation may be clinically accurate but fail to address the specific elements the payer expects to see.
Common documentation gaps include:
- Missing diagnosis details or supporting records
- Incomplete history of prior treatment
- Lack of a clear physician rationale
- Missing evidence of failed conservative treatment, when required
- Documentation that does not map directly to payer criteria
A medical necessity appeal should respond to the payer’s specific rationale, not simply resubmit the original information.
Technology classified as investigational or experimental
A payer may classify a device as investigational or experimental even when it has FDA clearance or approval. This classification is generally a coverage-policy determination, not an FDA regulatory determination.
FDA’s device clearance and approval resources describe separate regulatory pathways for devices. The FDA has also explained that coverage and payment decisions are made by payers and providers after a device is authorized for marketing.fda+1
When a technology is classified as investigational, the appeal may need to address the payer’s cited policy, the current evidence base, the technology’s intended use, and the patient-specific rationale.
What medical necessity and E/I denials mean for medical device manufacturers
For manufacturers, a medical necessity denial is not only an individual access issue. It can also identify a broader barrier involving payer policy, evidence communication, documentation expectations, or coding clarity.
A denied preauthorization or medical claim can affect provider confidence, patient access, reimbursement expectations, and future use of a technology. Tracking the reason for each denial helps manufacturers separate isolated issues from repeatable payer-level barriers.
Denials as data: turning case-level outcomes into policy strategy
Each denial contains information about how a payer evaluates a technology, including the language used, criteria applied, evidence requested, and arguments that succeed or fail.
Tracking patterns across cases can help organizations:
- Identify recurring payer denial reasons
- Strengthen prior authorization and claim documentation
- Refine appeal materials for specific payers
- Identify policy language that may not reflect current evidence
- Prepare for focused payer engagement where recurring barriers exist
Instead of treating every insurance denial for medical necessity as a separate event, manufacturers can use case-level findings to improve future submissions and inform a more durable access strategy.
How JDL Access helps fight medical necessity and E/I denials
JDL Access works with medical device manufacturers to address medical necessity and experimental/investigational denials as both immediate patient-access issues and longer-term payer-policy challenges.
We support evidence-based appeals, analyze denial patterns and payer responses, and help providers strengthen documentation and criteria mapping for authorizations and claims. This approach can help clarify whether the central issue is evidence, policy, coding, submission documentation, or a combination of factors.
For manufacturers navigating payer coverage barriers, case-level advocacy and data-informed policy strategy can help turn individual denials into a more sustainable path toward coverage.
If your organization needs help assessing a medical necessity denial or strengthening its
response strategy, explore JDL Access’s patient access support and contact our team to discuss available support options.
FAQs
Q1. What is a medical necessity denial?
A medical necessity denial occurs when a payer determines that a requested service, procedure, or device does not meet its coverage criteria for the patient’s documented condition. The denial may relate to the patient record, submitted documentation, diagnosis, payer policy, coding, or a technology-level coverage determination.
Q2. What are the most common medical necessity denial reasons?
Common reasons include incomplete documentation, a diagnosis that does not meet payer criteria, missing evidence of prior treatment, coding issues, lack of prior authorization, and a payer policy that does not cover the technology or indication. The denial notice and applicable policy should be reviewed to identify the specific issue.
Q3. How can I appeal a medical necessity denial effectively?
Start by reviewing the denial notice, EOB, payer policy, deadline, and any applicable denial or reason codes. Submit an appeal that directly addresses the payer’s stated rationale. Include the patient record, physician rationale, supporting evidence, and documentation that maps the request to relevant coverage criteria.
Q4. What documentation can support a medical necessity appeal?
Helpful documentation may include the patient’s diagnosis, treatment history, prior treatment outcomes, clinical notes, physician rationale, test results, peer-reviewed evidence, specialty-society guidance, FDA labeling, and relevant payer coverage policies. The strongest appeal connects this information directly to the payer’s stated denial reason.
Q5. What is a medical necessity denial code?
A medical necessity denial code is a claims-processing code that signals the payer denied or adjusted a claim because it determined the service was not covered as medically necessary. The code should be read with the EOB, remittance advice, written denial explanation, and applicable payer policy because code meanings vary by payer.
