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Case study

From Denial to Approval

A request for continued CGM coverage was denied on a plan criterion the patient did not meet. Here is how the care team responded, and why it worked.

Developed and reviewed by the ADCES Diabetes Technology Committee. Last reviewed October 2026

About this case: One case, shared for education. Payer criteria, appeal rights and timelines vary by plan. Patient details are de-identified.

The patientDe-identified
46-year-old womanwith type 2 diabetes mellitus
Diagnosis

E11.29Type 2 diabetes with other diabetic kidney complication

Medication Tirzepatide
10.0 mg12.5 mg

Weekly, in active dose escalation

Not taking

Insulin, sulfonylurea or meglitinide

CGM history

Established user with documented benefit

6.5%GMI
20.4%Coefficient of variation
NoneHypoglycemia
≥90%Sensor wear time, consistently
Request

Continued coverage of CGM sensors

ResultDenied
After appealApproved within 72 hours
!
Where it started

The denial

The payer’s denial letter stated that the plan covers CGM sensors only for members taking insulin, a sulfonylurea or a meglitinide. This was not a documentation problem. The submission was complete. The patient simply did not meet a written plan criterion, and no amount of additional chart material would change that fact.

Plan criterion for CGM coverage
  • Insulin Not taking
  • Sulfonylurea Not taking
  • Meglitinide Not taking
Criterion not met
1
Step 1 applied

Classify the denial before responding

The care team read the denial letter closely and correctly classified the denial type. This is the fork in the road that determines everything downstream. A documentation-gap denial is fixed by supplying the missing element. A criteria-based denial cannot be fixed that way, because the criterion is not in dispute and the patient genuinely does not meet it.

Recognizing this early prevented a common wasted step in appeals work: resubmitting the same clinical narrative with more attachments and expecting a different result.

The fork in the road
Documentation gapSupply the missing element
This caseCriterion not metMore chart material will not change the result
2
Step 2 applied

Confirm the criterion and what it is measuring

The DCES confirmed the plan’s published criterion and recognized that the requirement for insulin, sulfonylurea or meglitinide use appeared to function as a proxy for hypoglycemia risk.

Once that was named, the strategic question became clear. This patient’s medical necessity for CGM does not arise from hypoglycemia risk at all, so the appeal would need to request a medical necessity exception to the criterion rather than argue compliance with it.

The team also confirmed the filing window of 180 days from the denial date. That established both how much time was available and how quickly the strongest clinical arguments would lose force, since an active medication titration is a time-limited fact.

Reading the criterion
Insulin, sulfonylurea or meglitinide useThe plan’s written criterion
appeared to function as a proxy for
Hypoglycemia riskNot where this patient’s need for CGM comes from
so the appeal would
Request a medical necessity exceptionRather than argue compliance with the criterion
180day filing window from the denial date
3
Step 3 applied

Build the case on grounds the criterion does not capture

Rather than restate the original request, the team built the appeal on three independent clinical grounds, each supported by data already in the chart.

1Active titration of a potent glucose-lowering agent

Tirzepatide dose escalation was underway at the time of the appeal. In this case, continuous glucose data provided clinically useful information about glycemic response during active medication titration that intermittent sampling could not provide.

2Diabetic kidney disease requires verified glycemic control

Diabetic kidney disease (E11.29, type 2 diabetes with other diabetic kidney complication) increased the importance of maintaining individualized glycemic goals. CGM provided additional information about glucose patterns across the day and night to support ongoing treatment decisions and glycemic management.

3Current standards of care

Recommendation 9.25 of the ADA Standards of Care in Diabetes—2026 recommends CGM at diabetes onset and anytime thereafter for adults with diabetes who are on insulin therapy, on noninsulin therapies that can cause hypoglycemia or on any diabetes treatment where CGM aids in management. In this case, CGM was already providing clinically actionable information that informed nutrition and treatment decisions during active tirzepatide titration. The plan’s coverage criterion was more restrictive than current ADA clinical guidance, and the appeal stated this directly.

Citation: American Diabetes Association Professional Practice Committee for Diabetes. 9. Pharmacologic Approaches to Glycemic Treatment: Standards of Care in Diabetes—2026. Diabetes Care 1 January 2026; 49 (Supplement_1): S183–S215. https://doi.org/10.2337/dc26-S009

Documenting benefit already demonstrated

The team then documented benefits already demonstrated rather than benefits predicted. CGM-guided nutrition intervention had produced a GMI of 6.5% with a coefficient of variation of 20.4% and no hypoglycemia. CGM had identified specific actionable patterns, including postprandial excursions and evening and weekend elevations, that intermittent fingerstick testing had not surfaced in this case and that directly shaped the current treatment plan. Wear time above 90% established engagement. Since the coverage lapse, the patient had self-initiated four fingerstick checks daily, which the letter used as evidence of both her engagement and the insufficiency of fingersticks for the patterns in question.

Patterns CGM identified
  • Postprandial excursions
  • Evening elevations
  • Weekend elevations
4fingerstick checks a day, self-initiated after coverage lapsed

Coverage note: Four daily fingerstick checks were specific to this case, not a CGM coverage requirement. Medicare eliminated its four-times-daily fingerstick prerequisite in 2021. Coverage criteria vary by payer.

Handling facts that cut against you

Two facts required honest handling rather than omission.

The factHow the letter handled it
No hypoglycemiaA clinical win, but it worked against the payer’s stated coverage criterion in this case.

The letter did not hide it. It presented the absence of hypoglycemia in the context of CGM-guided management, rather than as evidence that monitoring was unnecessary.

Not on insulin, a sulfonylurea or a meglitinide

The letter conceded this plainly. Arguing otherwise would have cost credibility with the reviewer for no gain.

4
Step 4 applied

Escalate on two tracks at once

The team did not wait for a second denial before requesting a clinical conversation.

Track 1Written appeal, marked urgentThe appeal was submitted marked urgent, with a request for expedited review, on the basis that the coverage lapse had removed monitoring during an active medication titration and that the patient was paying out of pocket for an over-the-counter biosensor to bridge the gap.
Track 2Peer-to-peer as a fallbackWithin the same letter, the team requested a peer-to-peer discussion with a clinical reviewer as a fallback if the written appeal could not be approved, with the prescriber’s availability stated up front.

The payer accepted the expedited review request and issued a decision within 72 hours, rather than the 15–30 days allowed for standard review under this plan.

Objective evidence was attached as labeled exhibits with interpretive captions, so the reviewer did not have to interpret raw reports. Submission went by fax to preserve a same-day transmission confirmation as proof of timely filing, and the complete packet was retained in the chart in case a second-level appeal or external review became necessary.

Alongside the appeal

Bridging care during the appeal

At the visit where the denial was discussed, the DCES provided a 30-day supply of an over-the-counter biosensor in office, along with education on application, wear period and app setup. This kept clinical decision-making data-informed during titration and kept the patient engaged rather than idle while the appeal moved.

Outcome

Approved

Approved on written expedited review

Within the 72-hour expedited window

The patient received notification from her pharmacy that the CGM sensors were approved, within the 72-hour expedited window. The requested peer-to-peer was never needed.

Compared with the standard written appeal cycle, expedited handling compressed the monitoring gap from weeks to days, during the exact period the tirzepatide dose was being escalated.

Practice noteA pharmacy notification to the patient is the earliest signal, not the formal determination. Obtain the payer’s written approval letter and file it alongside the fax transmission confirmation, so the outcome is documented if coverage is questioned again.
What to take from it

Teaching points

  1. Diagnose the denial before you answer it.

    The instinct with a denial is to send more. The higher-yield move is to determine whether the denial is about missing documentation or about a criterion the patient does not meet, because those two denials call for opposite responses. When the criterion is the barrier, the appeal is not a resubmission. It is an argument that the criterion, which may stand in for one kind of risk, does not capture the actual clinical necessity in front of you.

  2. Ask for expedited review when the facts support it.

    Expedited review may be available when the circumstances meet the payer’s criteria for urgent handling. In this case, the team documented active medication titration, the loss of CGM coverage during that titration and the patient’s out-of-pocket cost for an over-the-counter biosensor as the basis for the request. The payer accepted the expedited request and issued a decision within its 72-hour expedited review window. When requesting expedited review, clearly state the clinical circumstances and other relevant factors supporting the request. If the clinical facts support expedited handling, ask for it explicitly and state the basis.

  3. Demonstrated benefit can outweigh predicted benefit to strengthen the case.

    For an established device user, the strongest evidence is already in the chart. Glycemic metrics, wear time and the specific clinical decisions the data produced are more persuasive than a general statement of what CGM can do.

Use it next time

Quick reference: applying this to your next denial

  • Read the denial letter and name the denial type before drafting anything.
  • Pull the payer’s current clinical policy or applicable coverage criteria and identify what the criterion requires and, when relevant, what clinical issue it may be intended to address.
  • If the patient cannot meet the criterion, request a medical necessity exception rather than arguing compliance.
  • Build the case on independent clinical grounds, each supported by dated chart data.
  • Address facts that cut against you directly instead of omitting them.
  • Attach evidence as labeled exhibits with captions that carry the key numbers in text.
  • When the payer’s expedited review criteria may be met, request expedited review and clearly document the basis for the request.
  • Request peer-to-peer within the same letter as a fallback, with prescriber availability stated.
  • Fax for a same-day transmission confirmation and retain the complete packet in the chart.
  • Consider a clinically appropriate bridge option so monitoring can continue while the appeal is pending. In this case, the DCES provided a 30-day supply of an over-the-counter biosensor. Depending on availability, manufacturer-provided CGM samples may also be used as a bridge. Providing the device along with education on application, wear period and app setup can support continued glucose monitoring during active medication titration while the appeal is under review.
Respond to a DenialPrior Authorization overview

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