Certificate of Medical Necessity: what it is, what changed, and what your doctor uses now

Short answer

In Medicare durable medical equipment, the Certificate of Medical Necessity was a paper trail your doctor filled out to justify equipment coverage. CMS retired the process on January 1, 2023 through bulletin SE22002. Your doctor now provides a Standard Written Order plus clinic notes from a face-to-face visit — the same information the CMN captured, but drawn from documentation your doctor already keeps. CMNs still exist in other contexts (state Medicaid, workers’ compensation), but not in Medicare DME.

What a Certificate of Medical Necessity was (and where it still applies)

A Certificate of Medical Necessity, or CMN, is a form that a physician signs to attest that a specific medical service, item, or treatment is medically necessary for a patient. The idea is straightforward: coverage decisions often turn on medical necessity, so payers historically asked doctors to certify it in a standard format.

The phrase “Certificate of Medical Necessity” appears in three broad contexts:

In Medicare durable medical equipment (retired). Medicare used a family of CMN forms for years — one form per equipment category. That process ended January 1, 2023 and is not part of Medicare DME today. This article covers what happened and what replaced it.

In state Medicaid programs (still active). Most state Medicaid agencies use their own CMN forms for various covered items. Missouri, Virginia, Illinois, and many other states publish their own certificates. If you’re on Medicaid or dual-eligible, your state’s CMN may still apply for certain claims.

In workers’ compensation and some private insurance (still active). The U.S. Department of Labor uses form OWCP-CM-893 for federal workers’ compensation claims. Many private insurance plans still require CMN forms for equipment or treatments. These are unrelated to the Medicare retirement.

The rest of this article focuses on the Medicare DME retirement, because that’s the change most beneficiaries and their families run into.

The Medicare DME CMN forms retired in 2023

On August 17, 2022, CMS published a newsroom announcement stating that the Certificate of Medical Necessity and DME Information Form (DIF) process would end for claims with dates of service on or after January 1, 2023. The technical bulletin, MLN Matters SE22002, spelled out the specifics.

Eight forms were retired:

• CMS-484 — Oxygen
• CMS-846 — Pneumatic Compression Devices
• CMS-847 — Osteogenesis Stimulators
• CMS-848 — Transcutaneous Electrical Nerve Stimulators (TENS)
• CMS-849 — Seat Lift Mechanisms
• CMS-854 — Section C Continuation Form
• CMS-10125 — External Infusion Pumps
• CMS-10126 — Enteral and Parenteral Nutrition

Since January 1, 2023, Medicare has rejected claims submitted with these forms attached. The CMS instruction is direct: “Don’t submit CMN or DIF forms with the claims or we’ll reject your claims and return them to you.”

Why CMS retired the CMN process

CMS gave two reasons in its 2022 announcement.

Administrative burden. The information on a CMN — the diagnosis, the medical history, the reason the equipment is needed — was already documented in your doctor’s clinic notes and on the claim itself. Filling out a separate form duplicated the effort.

Equity concerns for small and rural providers. CMS heard from doctors and suppliers that CMN paperwork was “particularly difficult for small or rural providers without administrative staff and technical support.” Retiring the forms freed those practices to focus on patient care.

The change didn’t lower Medicare’s standard for medical necessity. It just moved the proof of necessity from a dedicated form to documentation your doctor already keeps.

What your doctor uses now: SWO + face-to-face + clinic notes

For Medicare DME claims in 2026, three pieces of documentation together do what the CMN used to do.

1. A Standard Written Order (SWO). This is a short, structured order that your doctor signs before the equipment supplier bills Medicare. Per CMS, an SWO must include six specific items:

• Your name or Medicare Beneficiary Identifier (MBI)
• A description of the item (with billing codes or brand/model)
• Quantity, if applicable
• Your doctor’s name or National Provider Identifier (NPI)
• The date of the order
• Your doctor’s signature (date stamps are not accepted)

The supplier must receive the complete SWO before submitting the claim.

2. A face-to-face encounter within six months before the order. For most equipment on Medicare’s “Required List” (which includes wheelchairs, oxygen equipment, hospital beds, and dozens of other items), you have to have seen your doctor within the past six months for a visit related to the condition the equipment is treating. Telehealth visits count if they meet Medicare’s regulatory requirements.

3. Contemporaneous clinic notes. Your doctor’s notes from the face-to-face visit must document your diagnosis, your functional limitations, and why the equipment is medically necessary for your specific condition. CMS is explicit that supplier-prepared statements or physician attestations alone are not enough — “the beneficiary’s medical record must document the diagnosis, functional limitations, clinical course, and other pertinent information supporting the necessity for items ordered.” Records must be retained for seven years.

Together these three pieces prove medical necessity the same way the CMN once did — with less paperwork on your doctor’s side.

Where CMN forms are still used (not Medicare DME)

The 2023 retirement applies only to Medicare DME. Elsewhere, CMN forms remain in active use.

State Medicaid. Most states have their own certificate. Missouri’s is Form 2575-016; Virginia publishes an DME-supplies CMN; other states publish variants. If you’re enrolled in Medicaid or you’re dual-eligible with Medicare and Medicaid, some Medicaid claims may still require a state CMN even though the Medicare side doesn’t.

Workers’ compensation. The federal workers’ compensation program uses form OWCP-CM-893, “Certificate of Medical Necessity.” State workers’ comp programs often use their own versions.

Private insurance. Many private and Medicare Advantage plans still ask for a CMN for equipment coverage. Because Medicare Advantage plans have to cover what Original Medicare covers but can add their own paperwork on top, some MA plans continue to use CMN-style forms for their own utilization review.

Certain non-DME Medicare items. A small number of Medicare-covered items outside the DME category (some supplies, some services) may still involve certification paperwork, but they don’t use the retired CMN forms.

If you see a form titled “Certificate of Medical Necessity” today, check who is asking for it. If it’s an ambulance company, a state Medicaid office, a workers’ comp adjuster, or a private insurance plan, the form is likely still valid. If it’s a Medicare DME supplier and the claim will go to Original Medicare, something has gone wrong.

If a Medicare DME supplier asks you for a CMN in 2026

CMS retired the process almost three years ago, but the words “Certificate of Medical Necessity” still show up in older supplier documents, marketing materials, and even on some legacy paper forms. Here’s what to do if a Medicare DME supplier hands you one:

• Confirm the supplier is billing Medicare, not Medicaid or a Medicare Advantage plan. If it’s straight Original Medicare, no CMN is needed.
• Ask the supplier to work directly with your doctor on the Standard Written Order. That’s the required paperwork now. Your doctor already has the diagnosis, the visit note, and the clinical reasoning.
• If the supplier insists on a CMN for Medicare DME, ask for the reason in writing. This is a red flag that the supplier is out of date or is processing your claim incorrectly.
• Do not fill out or sign a CMN yourself. The historical CMN was signed by the doctor, not the beneficiary. Modern SWOs are signed by the doctor too.
• If the equipment has been denied, you can appeal — Medicare uses the same five-level appeals process as for any Part B claim. The medical-necessity argument now rests on your doctor’s clinic notes and SWO, not on a CMN.

How Baba helps

• Explains the CMN retirement in plain language so you know why old paperwork you may have kept doesn’t apply anymore.
• Coordinates with your doctor on the Standard Written Order and face-to-face visit documentation your DME supplier actually needs.
• Reads the paperwork before you sign. If a supplier hands you a form labeled “Certificate of Medical Necessity” for a Medicare DME claim, we can tell you whether it belongs in the record.
• Handles claim denials. If Medicare denies your DME coverage on medical-necessity grounds, we work with your doctor on the clinic-notes package that supports an appeal — the same information the CMN once carried.
• Distinguishes Medicare from Medicaid and workers’ comp if you’re dual-eligible or have overlapping coverage. Different programs still require different paperwork.
• Escalates through the five levels of Medicare appeals if needed — from Level 1 redetermination through federal court in the rare case that’s warranted (2026 amount-in-controversy: $200 at ALJ, $1,960 at federal court).

Call (855) 765-9011 or schedule a call to have a Baba advocate review a DME coverage question or a piece of paperwork you were asked to sign.

Frequently asked questions

Do I still need a Certificate of Medical Necessity for oxygen from Medicare?

No. The CMS-484 (Oxygen CMN) was retired January 1, 2023. Your doctor now provides a Standard Written Order and clinic notes from a face-to-face visit that establishes the oxygen-coverage criteria (arterial blood gas or oxygen saturation values).

What replaced the CMN for a wheelchair?

For wheelchairs and other equipment on Medicare’s Required List, your doctor provides a Standard Written Order after a face-to-face encounter within the past six months. The clinic note has to document your mobility limitations and why the wheelchair is medically necessary.

Can my doctor still submit a CMN if they want to?

No — for Medicare DME claims, Medicare will reject the claim if a CMN is attached. The old forms are inactive in the Medicare DME context.

I have an old CMN from before 2023 in my records — is it still valid?

For a claim with a date of service before January 1, 2023, the CMN was the correct paperwork. For dates of service after that, only the SWO plus clinic notes apply. You don’t need to do anything with old CMNs in your personal records; keep them for your own reference.

My Medicare Advantage plan asked me for a CMN — is that legal?

Medicare Advantage plans can add their own utilization-review paperwork on top of what Original Medicare requires. If your MA plan uses a CMN-style form for its own approval process, that’s the plan’s rule, not Medicare’s. Ask the plan for its written medical policy so you know what documentation it wants.

Where can I download the retired Medicare DME CMN forms?

The forms are archived on cms.gov but should not be used for current Medicare DME claims. If you find yourself needing one for a non-Medicare purpose (a state Medicaid claim, workers’ comp, or private insurance), check with that program directly for the correct current form.

This information is for educational purposes and should not substitute for professional guidance. Healthcare coverage details vary by individual plan. Consult with Baba’s support team or your insurance provider for information specific to your situation.