Disclosure: This site may earn affiliate commissions when you click provider links. This doesn't affect our recommendations. Learn more
A patient-friendly playbook for drafting a Letter of Medical Necessity for Wegovy or Zepbound, with a copy-ready template, ICD-10 codes, and 2026 timing rules.
A Letter of Medical Necessity, or LMN, is the document your prescribing clinician sends to your insurance company explaining why a specific medication is the right treatment for your specific situation. For Wegovy and Zepbound, an LMN is often the difference between a prior authorization that gets approved and one that gets denied for "insufficient clinical justification." The letter is signed by your clinician, but the patient who walks in with a draft already structured around the right diagnosis codes, BMI documentation, and FDA-approved indication wording almost always gets a stronger letter out the door. If you want a telehealth team to handle the paperwork for you, Found is one provider in our network that runs a free insurance check upfront and supports prior authorization for brand-name GLP-1s including Wegovy and Zepbound.
Last verified: 2026-05-29 by RxPickr Editorial Team. Pricing, FDA-approved indications, ICD-10 codes, and CMS prior authorization timing rules below were verified from primary sources on the date shown. Read our methodology for how we evaluate and re-verify provider data.
This guide gives you a copy-ready LMN template, the ICD-10 codes that belong on it, a document checklist to gather before your visit, and the federal timing rules that govern how quickly your insurer must respond in 2026. If you have not started the prior authorization yet, read our companion guide on getting prior authorization for Wegovy or Zepbound first. If you already have a denial in hand, jump to our appeals playbook instead.
A Letter of Medical Necessity is not a magic document. It is structured clinical advocacy. The insurer's reviewer compares the letter against the plan's coverage criteria for the requested drug, then either approves, denies, or asks for more information. A strong LMN does three things on a single page:
Insurers train their reviewers to look for those three elements. If any one is missing, the request gets bounced.
There is a federal rule worth knowing before you draft anything. Under the CMS Interoperability and Prior Authorization Final Rule (CMS-0057-F), which took effect January 1, 2026, impacted payers must send prior authorization decisions within 72 hours for expedited requests and within 7 calendar days for standard requests (CMS, 2024). Impacted payers include Medicare Advantage plans, Medicaid and CHIP fee-for-service and managed care, and Qualified Health Plan issuers on the Federally Facilitated Exchanges, per the same CMS rule. Those clocks start ticking once the insurer has a complete packet, which means a well-built LMN is also the fastest path to a decision.
Most LMNs fail because they reference clinical history that the prescriber never documented in the chart. Gather these records before you draft anything. If something is missing, you may need an office visit first to get it documented.
If you are working with a telehealth provider, ask the care team which of these they pull on your behalf. Ro (ro.co), PlushCare (plushcare.com), Found (joinfound.com), and Mochi Health (joinmochi.com) all have insurance coordination workflows, but the depth varies.
Every diagnosis on the LMN needs a corresponding ICD-10-CM code. The reviewer matches the codes against the plan's coverage policy. Use these official 2026 ICD-10-CM codes (ICD10Data, 2026 ICD-10-CM):
| Code | Description | When to use it |
|---|---|---|
| E66.01 | Morbid (severe) obesity due to excess calories | BMI 40 or higher, or BMI 35 to 39.9 with a documented comorbidity |
| E66.9 | Obesity, unspecified | BMI 30 to 34.9 without further specification |
| E66.3 | Overweight | BMI 25 to 29.9, used when requesting on the comorbidity pathway |
| Z68.41 | Body mass index 40.0 to 44.9, adult | Paired with E66.01 |
| Z68.42 | Body mass index 45.0 to 49.9, adult | Paired with E66.01 |
| Z68.43 | Body mass index 50.0 to 59.9, adult | Paired with E66.01 |
| Z68.44 | Body mass index 60.0 to 69.9, adult | Paired with E66.01 |
| Z68.45 | Body mass index 70 or greater, adult | Paired with E66.01 |
| E11.9 | Type 2 diabetes mellitus without complications | Comorbidity supporting medical necessity |
| I10 | Essential (primary) hypertension | Comorbidity supporting medical necessity |
| E78.5 | Hyperlipidemia, unspecified | Comorbidity supporting medical necessity |
| G47.33 | Obstructive sleep apnea (adult, pediatric) | Comorbidity supporting medical necessity |
ICD-10-CM coding guidelines require that an E66 obesity code be paired with the appropriate Z68 BMI code on the claim. The reviewer treats a missing Z68 code as missing BMI documentation, which is a common reason for denial.
Quote the FDA-approved indication directly in your LMN. Reviewers are trained to look for it.
Wegovy (semaglutide 2.4 mg) is FDA-approved to reduce excess body weight and maintain weight reduction long term in adults and pediatric patients aged 12 years and older with obesity, or in adults with overweight in the presence of at least one weight-related comorbid condition (DailyMed, Wegovy prescribing information). This article scopes to the adult use case. In standard clinical practice, "obesity" is defined as a BMI of 30 or greater and "overweight" as a BMI of 27 or greater; those numeric thresholds are clinical definitions, not direct label quotations.
Zepbound (tirzepatide) is FDA-approved to reduce excess body weight and maintain weight reduction long term in adults with obesity, or adults with overweight in the presence of at least one weight-related comorbid condition (DailyMed, Zepbound prescribing information). The Zepbound pivotal trial (Study 1) enrolled participants with weight-related comorbidities including dyslipidemia, hypertension, obstructive sleep apnea, and cardiovascular disease; these are clinically recognized weight-related comorbidities, but the label's indication paragraph uses the general phrase "at least one weight-related comorbid condition" rather than enumerating a defined list.
Use the indication wording for whichever drug you are requesting. Do not mix them.
Copy this template into a document, fill in every bracket, and bring it to your prescribing clinician's visit. The letter must go out on the clinician's letterhead, signed by them, with their NPI and DEA where applicable. Anything you cannot fill in is a sign that you need to either get the underlying record documented at your next visit or remove that line entirely.
[Clinician Letterhead]
[Date]
[Insurance Company Name]
Attention: Prior Authorization / Medical Review
[Insurance Company Address]
Re: Letter of Medical Necessity
Patient: [PATIENT FULL NAME]
Date of Birth: [DOB]
Member ID: [MEMBER ID]
Group Number: [GROUP NUMBER]
Medication Requested: [Wegovy 2.4 mg subcutaneous injection weekly | Zepbound (DOSE) mg subcutaneous injection weekly]
ICD-10 Diagnoses: [E66.01 - Morbid (severe) obesity due to excess calories]; [Z68.41 - BMI 40.0-44.9, adult]; [add comorbidity codes as applicable]
To Whom It May Concern:
I am writing to request prior authorization for [Wegovy / Zepbound] for the above-named patient. I have evaluated this patient and determined that [Wegovy / Zepbound] is medically necessary for the long-term management of obesity.
Clinical history: [PATIENT NAME] is a [AGE]-year-old [sex] with a [DURATION]-year history of obesity. Current vital signs documented at the [DATE] office visit show height [HEIGHT], weight [WEIGHT], and BMI [BMI]. Historical BMI on [PRIOR DATE] was [PRIOR BMI], confirming chronic obesity rather than a transient elevation.
Comorbid conditions: The patient has the following documented weight-related comorbidities:
- [Type 2 diabetes mellitus (E11.9), most recent A1c [VALUE]% on [DATE]]
- [Essential hypertension (I10), most recent BP [VALUE] mmHg on [DATE], currently on [MEDICATIONS]]
- [Hyperlipidemia (E78.5), most recent LDL [VALUE] mg/dL on [DATE]]
- [Obstructive sleep apnea (G47.33), confirmed by polysomnography on [DATE]]
Prior weight-loss attempts: The patient has previously attempted weight reduction through the following evidence-based interventions, each documented in the chart:
- [Medically supervised diet and exercise program, [DATES], resulting in [OUTCOME]]
- [Trial of [phentermine / naltrexone-bupropion / orlistat], [DATES], discontinued due to [REASON / inadequate response]]
- [Behavioral / nutritional counseling, [DATES]]
Each of these interventions produced either no clinically meaningful weight loss or weight regain to baseline, establishing that conservative therapy alone is insufficient.
FDA-approved indication: [Wegovy is FDA-approved to reduce excess body weight and maintain weight reduction long term in adults with obesity, or adults with overweight in the presence of at least one weight-related comorbid condition, per the prescribing information (DailyMed setid ee06186f-2aa3-4990-a760-757579d8f77b).] [Zepbound is FDA-approved for the same indication per its prescribing information (DailyMed setid 487cd7e7-434c-4925-99fa-aa80b1cc776b).] In standard clinical practice, obesity is defined as a BMI of 30 kg/m² or greater and overweight as a BMI of 27 kg/m² or greater. This patient meets the FDA-approved indication based on [BMI of [VALUE] / BMI of [VALUE] in the presence of [COMORBIDITY]].
Requested treatment plan: I am requesting approval for [Wegovy 2.4 mg weekly subcutaneous injection, with standard dose escalation from 0.25 mg per the FDA-approved titration schedule | Zepbound subcutaneous injection starting at 2.5 mg weekly with titration to maintenance per the FDA-approved schedule] for an initial 6-month course, with continuation contingent on documented weight reduction of at least 5% from baseline.
The patient will be monitored at minimum every 3 months for tolerability, weight response, and any adverse effects. I will discontinue treatment if no clinically meaningful weight reduction occurs by 12 weeks at the maintenance dose.
Based on the documented clinical history, comorbidity burden, and prior treatment failures, [Wegovy / Zepbound] is medically necessary for this patient. I appreciate your timely review under the prior authorization timing requirements established by CMS-0057-F. If you require additional clinical documentation, please contact my office at [PHONE].
Sincerely,
[Clinician name, credentials]
NPI: [NPI NUMBER]
[Practice name]
[Address]
[Phone] | [Fax]
The strongest LMNs are short, specific, and quote the FDA-approved indication verbatim. Letters that exceed two pages tend to get skimmed, and reviewers cannot find what they are looking for. Keep it tight.
Answer 10 questions and get a personalized recommendation.
Take the free quiz →Once you have a draft and your records, the workflow is straightforward.
1. Bring the draft to your prescribing visit. If you are seeing a telehealth clinician, message it through their portal before the appointment. If you are seeing an in-person clinician, print two copies. Ask them to review it for clinical accuracy, edit any details, and produce it on their letterhead.
2. Confirm the clinician's office will submit the LMN with the PA request. Most prescribers submit the LMN as supporting documentation alongside the prior authorization form their staff completes. The LMN does not replace the PA form, it accompanies it.
3. Get a confirmation number from your insurer. When the PA is submitted, ask for a reference number and the name of the reviewer or department handling it. Put that in your records.
4. Follow up within the CMS-required window. Under CMS-0057-F, expedited decisions are due in 72 hours and standard decisions in 7 calendar days for impacted payers (CMS, 2024). If you have not heard back by day 8 for a standard request, call the insurer and reference your confirmation number. Late decisions are themselves a basis for escalation.
5. Read the response carefully. An approval will state the approved dose and the authorization period (often 6 or 12 months). A denial must state a specific reason under the 2026 CMS rule, which tells you exactly what to fix on appeal.
Pros
Cons
A denial is not the end of the process. Under the federal appeal framework, you have multiple levels of review available, and each step has its own clock.
For employer-sponsored ERISA plans, you have at least 180 days from the date of denial to file an internal appeal. Marketplace and individual plans follow the same minimum under the Affordable Care Act. After exhausting internal appeals, you have four months from the final internal denial to request an external review by an Independent Review Organization, whose decision is binding on the plan (HealthCare.gov, External Review).
The most productive thing to do with a rejected LMN is to read the denial letter line by line, identify the specific clinical gap the reviewer cited, then revise the LMN to address that exact gap with documented evidence. A revised LMN that closes the cited gap is the single highest-yield appeal document.
Our companion guide walks through every step of the appeals process: How to Appeal a Wegovy or Zepbound Insurance Denial. It covers peer-to-peer review, internal appeals, external review, and the cash-pay fallbacks if the appeal fails.
Found
$149/mo medication + $99–$149/mo CORE membership = $248–$298/mo total (May 2026)
Free insurance check upfront. Found's care team runs insurance coordination and supports prior authorization for brand-name Wegovy and Zepbound.
A few things that move LMNs from "okay" to "approved":
The LMN is not a guarantee of approval, but it is the single piece of the prior authorization packet that you, as the patient, can most directly influence. Walking in with a draft, the records to back it up, and the FDA indication quoted verbatim is the highest-leverage thing you can do before your clinician picks up a pen. Always consult a licensed healthcare provider before starting, changing, or stopping any medication.