Prescription, Assignment of Benefits & Letter of Medical Necessity Guide

by Service, Training and Support·February 19, 2026

InterferentialNeuromuscular (NMES)TENS

Prescription, Assignment of Benefits and Letter of Medical Necessity for DME

Ordering a rehabilitation device may involve several forms, but those documents do not serve the same purpose.

A prescription or Standard Written Order identifies what the practitioner ordered. The medical record supports why the item is needed. A letter of medical necessity can summarize the clinical rationale. An assignment of benefits may allow an insurer to pay the supplier directly. Proof of delivery documents show that the patient received the item. An Advance Beneficiary Notice addresses expected noncoverage by Original Medicare in specific circumstances.

Completing one document does not automatically satisfy the requirements of the others, and none of these forms guarantees insurance payment.

Documentation notice: This guide is educational and is not legal, billing, or payer-specific advice. Suppliers and healthcare providers should verify current requirements with the applicable payer, DME Medicare Administrative Contractor, accrediting body, compliance adviser, and legal counsel.

For help choosing between sensory-level TENS and contraction-based NMES, read our TENS vs. NMES device guide.

Standard written order requirements for durable medical equipment

DME documentation forms compared

DocumentPrimary purposeUsually completed or signed byWhat it does not prove
Prescription or Standard Written OrderIdentifies the item being orderedTreating practitionerThat coverage criteria are met
Medical recordDocuments the patient-specific condition, evaluation and treatment planTreating healthcare professionalsThat the supplier delivered the item
Letter of Medical NecessitySummarizes why a particular item is requestedTreating practitionerCoverage by itself
Assignment of BenefitsRequests direct insurer payment to the supplier when permittedPatient or authorized representativeEligibility, coverage or payment amount
Release of InformationPermits or acknowledges certain information disclosuresPatient or authorized representative when requiredAssignment of insurance benefits
Prior authorization requestRequests payer review before dispensing or billingSupplier and treating practitionerFinal payment after delivery
Advance Beneficiary NoticeNotifies an Original Medicare beneficiary of expected noncoverageSupplier/provider and beneficiaryCoverage by another insurance plan
Proof of DeliveryDocuments that the item was deliveredRecipient/designee or delivery carrier recordsMedical necessity
Claim formRequests payer adjudication and paymentSupplier or providerThat the claim will be approved

CMS requires a written order, supporting medical-record information, correct coding, and proof of delivery for Medicare DMEPOS claims. The exact additional requirements depend on the item and applicable policy. Centers for Medicare & Medicaid Services

1. Prescription or Standard Written Order

For Medicare DMEPOS claims, the prescription is generally called a Standard Written Order, or SWO.

Required Medicare SWO elements

Required elementExample
Beneficiary name or Medicare Beneficiary IdentifierJane Doe or the patient’s MBI
Description of the itemDual-channel neuromuscular electrical stimulator
Quantity, when applicableOne device; four electrodes
Order dateJuly 24, 2026
Treating a practitioner's name or NPIPractitioner name and NPI
Treating the practitioner's signatureValid handwritten or electronic signature

CMS requires the completed order to reach the supplier before the supplier submits a Medicare claim. Certain products appearing on the current face-to-face and written-order-prior-to-delivery list require the order before delivery rather than merely before claim submission. Centers for Medicare & Medicaid Services

Useful supplemental fields

Depending on the item and payer, the order may also contain:

Supplemental fieldWhy it may be useful
Diagnosis and ICD-10-CM codeHelps identify the condition associated with the order
Manufacturer and modelReduces ambiguity about the item
HCPCS codeSupports supplier processing when correctly selected
Accessories and suppliesIdentifies leads, electrodes or other ordered components
Frequency or scheduleMay be relevant to the treatment plan
Length of needMay be requested by a payer or supplier
Laterality or treatment regionClarifies the clinical application
Clinical goalDistinguishes pain modulation from muscle activation
Special settingsRelevant when the practitioner is specifying a particular program
Supporting records requestedHelps coordinate chart-note submission

These supplemental fields do not replace the practitioner’s underlying medical record.

Signature correction

The current form says “Prescriber Signature (handwritten).” Medicare permits an acceptable handwritten or electronic signature. Signature and date stamps are generally not accepted, subject to limited exceptions described by CMS.

Recommended wording:

Treating practitioner signature: Handwritten or compliant electronic signature. Signature and date stamps are generally not accepted for Medicare documentation.

2. Medical records and letters of medical necessity

The medical record should establish the clinical facts supporting the order. Depending on the item, that may include the following:

  • Diagnosis and relevant history
  • Objective examination findings
  • Functional limitations
  • Prior and current treatment
  • Why the requested item is appropriate
  • Why a less complex alternative is insufficient
  • Expected treatment goal
  • Patient ability or caregiver support for using the equipment
  • Continued need and continued use when applicable

A letter of medical necessity can provide a concise summary, particularly for a prior-authorization request or appeal. It should be individualized to the patient and should not consist solely of copied coverage-policy language.

Important Medicare limitation

A supplier-produced form or letter of medical necessity—even when signed by the ordering practitioner—is not considered a substitute for the practitioner’s medical record for Medicare payment purposes. The information must be supported by contemporaneous chart documentation.

CMS also discontinued its former Certificates of Medical Necessity and DME Information Forms for claims with dates of service on or after January 1, 2023. Medical necessity is now supported through the order, claim information, applicable policy requirements, and medical record rather than the discontinued CMN/DIF process.

Letter-of-medical-necessity outline

SectionInformation to include
Patient identificationName, date of birth and payer/member information
Treating practitionerName, credentials, NPI, and contact information
DiagnosisRelevant diagnosis and current clinical status
Functional limitationWhat the patient cannot do or does only with difficulty
Objective findingsStrength, atrophy, range, pain interference or other findings
Prior treatmentRelevant therapy, medication, surgery, exercise or other interventions
Requested itemExact device, model, modality and necessary accessories
Clinical rationaleWhy this item is appropriate for this patient
Alternative consideredWhy a simpler or different option is insufficient
Treatment planHow the item will be integrated into rehabilitation
Expected outcomeA measurable clinical or functional objective
Length of needEstimated duration when relevant
Supporting documentsNotes, evaluation, operative report or plan of care
CertificationPractitioner signature and date

Sample LMN narrative

Re: [Patient name and date of birth]
The patient has been evaluated for [diagnosis], which currently results in [specific impairment and functional limitation]. Objective findings include [patient-specific findings].
The requested [exact device and model] is medically appropriate because [explain the relationship between the device, impairment and rehabilitation goal]. The device will be used as part of the patient’s plan of care to support [measurable treatment objective].
Prior or alternative interventions have included [relevant interventions]. These have been insufficient because [patient-specific explanation].
The anticipated length of need is [duration]. Supporting medical-record documentation is attached.
Treating practitioner name, NPI, signature and date

Avoid generic statements such as “the device is medically necessary” without explaining the patient’s diagnosis, findings, functional limitation, and expected benefit.

3. Assignment of Benefits

An assignment of benefits, commonly abbreviated AOB, asks the insurer to direct covered payment to the supplier or provider when the plan and applicable law allow it.

For Medicare, accepting assignment generally means that the participating provider or supplier accepts the Medicare-allowed amount as payment in full, apart from applicable deductible and coinsurance obligations.

An AOB does not:

  • Confirm that the patient is eligible
  • Establish medical necessity
  • Guarantee prior authorization
  • Guarantee that the item is covered
  • Guarantee payment to the supplier
  • Override plan exclusions
  • Replace an ABN
  • Create proof of delivery
  • Permit charges prohibited by the payer contract or law

Recommended AOB concept

To the extent permitted by my health plan and applicable law, I request that benefits payable for covered items be paid directly to the supplier. I authorize the supplier to submit claims on my behalf. I understand that assignment of benefits does not guarantee coverage or payment and that I may remain responsible for applicable deductibles, coinsurance, copayments, and valid noncovered charges after any notice required by law or payer policy.

Avoid stating that the patient is responsible for “all balances not paid by insurance” without accounting for:

  • Contractual adjustments
  • Medicare assignment rules
  • Balance-billing restrictions
  • Valid ABN requirements
  • State law
  • Medicaid restrictions
  • Workers’ compensation or auto-insurance rules

4. Assignment of Benefits vs. release of information

An assignment of benefits concerns where payment is directed. A release or authorization concerns how information may be shared.

HIPAA generally permits covered entities to use or disclose protected health information for treatment, payment, and healthcare operations without obtaining a separate authorization for every routine transaction. Broader disclosures may require a valid authorization or another applicable legal basis.

For that reason, avoid presenting one broad paragraph as though it were simultaneously

  • A legally complete AOB
  • A HIPAA authorization
  • A notice-of-privacy-practices acknowledgment
  • A release of medical records
  • A financial-responsibility agreement

A safer form structure is

SectionSeparate acknowledgment
Assignment of benefitsDirect-payment request
Claim-processing disclosureInformation needed for eligibility, medical necessity and payment
Privacy noticeAcknowledgment that the notice was provided
Broader authorizationSeparate form when required
Financial responsibilityCost-sharing and valid noncovered-charge terms

The exact wording should reflect Balego’s role in the transaction, its HIPAA status, payer contracts, and state law.

5. Proof of delivery

Proof of delivery, or POD, documents that the beneficiary actually received the ordered DMEPOS item.

CMS recognizes three general delivery methods:

  1. Direct delivery by the supplier
  2. Delivery through a shipping or mail-order service
  3. Delivery to a nursing facility on behalf of the beneficiary

The documentation requirements vary with the delivery method.

Direct supplier delivery

The delivery record should ordinarily identify:

  • Beneficiary
  • Delivery address
  • Item and quantity
  • Date delivered
  • Recipient or authorized designee
  • Recipient/designee signature
  • Serial number when relevant

Commercial shipping or mail order

Carrier and shipping records may be used to establish shipment or delivery according to Medicare’s applicable requirements. A patient should not be asked to sign a proof-of-delivery statement before the package has actually been delivered. Centers for Medicare & Medicaid Services

Retention

Medicare suppliers must retain proof-of-delivery documentation for seven years from the date of service. Centers for Medicare & Medicaid Services

Direct delivery: Recipient or authorized designee signs and dates after receiving the item. Commercial shipping: Retain the shipping-service documentation required by the applicable payer. Do not pre-sign proof of delivery.

The AOB may be signed before the item is supplied. The POD should document the later delivery event.

6. Advance Beneficiary Notice of Noncoverage

A generic financial-responsibility clause is not a substitute for the Medicare Advance Beneficiary Notice of Noncoverage, Form CMS-R-131.

Providers and suppliers use the official ABN for Original Medicare beneficiaries when Medicare payment is expected to be denied in situations where advance notice is required to shift potential financial liability to the beneficiary. Centers for Medicare & Medicaid Services

DocumentPurpose
Assignment of BenefitsRequests direct insurer payment
Financial-responsibility agreementExplains applicable patient charges
ABN CMS-R-131Gives advance notice of expected Original Medicare noncoverage
Explanation of BenefitsReports the payer’s claim decision after processing
When an Original Medicare ABN is required, use the current official CMS-R-131 form and instructions. Commercial plans, Medicare Advantage plans, Medicaid programs, workers’ compensation carriers, and auto insurers may use different notices.

CMS updated its ABN page and forms in July 2026, reinforcing the importance of linking users to the current official version rather than embedding a potentially outdated facsimile. Centers for Medicare & Medicaid Services

7. Face-to-face, prior authorization, and order-before-delivery rules

Not every DMEPOS item is subject to the same pre-delivery requirements.

All Medicare DMEPOS claims require a written order, but only products placed on the applicable required list need both a qualifying face-to-face encounter and a written order prior to delivery as a condition of payment. Other items generally require the order before claim submission. Centers for Medicare & Medicaid Services

As of April 13, 2026, CMS reports 83 items on its face-to-face encounter and written-order-prior-to-delivery list. The list changes over time and should be checked before dispensing an item. Centers for Medicare & Medicaid Services

Before supplying equipment, verify:

VerificationQuestion
Benefit eligibilityIs the patient currently enrolled?
Supplier statusMay the supplier bill this plan for the item?
Item coverageIs the device included in the benefit?
Diagnosis criteriaDoes the patient meet the current policy?
Face-to-face requirementIs a qualifying encounter required?
WOPD requirementMust the order be received before delivery?
Prior authorizationMust approval be obtained first?
Rental or purchaseHow does the plan classify the item?
Trial requirementIs a monitored trial required?
Network ruleMust a contracted supplier be used?
Cost sharingWhat deductible or coinsurance applies?
DocumentationWhich chart notes and tests are required?

A benefits inquiry or prior-authorization approval still may not guarantee final payment if claim, coding, eligibility, delivery, or documentation requirements are not met.

TENS and NMES coverage documentation

TENS and NMES may look similar, but their clinical purposes and coverage criteria differ. Our explanation of the device distinction is in the TENS vs. NMES guide.

TopicTENSNMES
Principal responseSensory stimulationMuscle contraction
Common purposeTemporary pain modulationMuscle activation and neuromuscular rehabilitation
Medicare policy focusSelected acute postoperative or chronic intractable pain criteriaSelected disuse-atrophy and narrowly defined FES uses
Important documentationPain condition, duration, prior treatment and trial responseAtrophy, intact nerve supply, cause of disuse and rehabilitation plan
Coverage assumptionShould not be assumed from a prescription aloneShould not be assumed from a diagnosis of weakness alone

Medicare TENS considerations

The current Medicare TENS LCD describes coverage for the following:

  • Acute postoperative pain, generally limited to a 30-day rental period
  • Certain chronic intractable pain other than chronic low-back pain
  • A monitored trial period for qualifying chronic pain before purchase coverage

The same LCD excludes or limits various pain presentations and requires the ordering practitioner to be treating the condition supporting the request. Centers for Medicare & Medicaid Services

Medicare’s national chronic-low-back-pain policy restricted TENS coverage to approved clinical studies during a defined coverage-with-evidence-development period. Routine Medicare coverage for chronic low-back pain should therefore not be assumed. Centers for Medicare & Medicaid Services

Medicare NMES considerations

Medicare’s national NMES policy limits coverage for muscle atrophy to disuse atrophy, where the nerve supply to the muscle remains intact. Examples include selected cases involving casting or splinting, scar-related contracture, and recovery after hip replacement until orthotic training begins. Centers for Medicare & Medicaid Services

The current page’s supplemental questions are concerning:

  • Disuse atrophy
  • Intact nerve supply
  • Muscles and nerves being stimulated
  • Surgery
  • Rehabilitation plan

are therefore useful for a Medicare-focused NMES request. However, the questions should appear in a separate payer-specific NMES supplement, not as universal requirements for every prescription.

A clinician may use NMES for other medically appropriate purposes, but a valid clinical use does not automatically mean that a particular payer covers a home device.

For a more detailed explanation, link to our NMES billing and documentation guide.

Recommended TENS/NMES order fields

FieldTENS orderNMES order
Exact device descriptionYesYes
QuantityYesYes
DiagnosisYesYes
Treatment regionUsefulUseful
Pain duration and causeImportantUsually secondary
Prior pain-treatment trialOften importantPayer-dependent
Monitored TENS trial responseMay be requiredNot applicable
Muscle atrophy documentedNot applicableImportant for disuse-atrophy coverage
Cause of disuseNot applicableImportant
Nerve supply intactNot applicableImportant
Muscles targetedOptionalImportant
Rehabilitation planUsefulImportant
Length of needPayer-dependentPayer-dependent
Practitioner signature/dateRequiredRequired

Product type and documentation comparison

Balego optionPrimary modalityDocumentation consideration
Balego TENS Digital EditionOTC TENSOTC availability does not establish insurance coverage
Balego EMS Digital NMES StimulatorDedicated NMES/EMSCoverage requires a payer-supported indication and medical-record documentation
Twin Stim IVTENS and NMESVerify whether the payer covers the ordered modality and combination-device configuration
Chattanooga ContinuumPrescription TENS and NMESDocument why the prescription combination system is required
Primera TENS/NMESTENS and NMESMatch the professional or OTC model to the order and treatment plan
Balego TENS/NMES/FES ElectrodesReplacement electrodesSupply quantity and replacement frequency remain payer specific

The Balego TENS is a dedicated sensory-stimulation device, while the Balego NMES is designed for motor-level stimulation and timed muscle-contraction programs. Combination devices provide both modalities but should not be assumed to fit every payer’s equipment classification.

Recommended DME documentation workflow

1. Identify the payer

Determine whether the request involves:

  • Original Medicare
  • Medicare Advantage
  • Medicaid
  • Commercial insurance
  • Workers’ compensation
  • Auto insurance
  • Self-pay purchase

Do not apply Medicare documentation rules automatically to a commercial or workers’ compensation claim.

2. Confirm the device and treatment goal

Determine whether the request is for:

  • TENS pain modulation
  • NMES muscle stimulation
  • A combination device
  • Replacement electrodes or lead wires
  • Another rehabilitation item

3. Verify benefits and supplier eligibility

Confirm coverage, network status, prior authorization, rental or purchase rules, and documentation requirements.

4. Obtain the patient-specific medical record

Collect the evaluation, relevant progress notes, operative report, plan of care, or other documentation supporting the item.

5. Obtain a complete SWO

Verify all six standard elements before claim submission and before delivery when WOPD rules apply.

6. Request an LMN when useful

Use an individualized LMN for complex cases, prior authorization, reconsideration, or appeal. Do not rely on it as the only supporting record.

7. Complete separate patient acknowledgments

Use separate or clearly identified sections for:

  • Assignment of benefits
  • Privacy and claim-processing disclosures
  • Financial responsibility
  • Privacy-notice acknowledgment

8. Issue any required advance notice

Use the official CMS-R-131 ABN for Original Medicare when applicable. Follow the appropriate payer’s process for other plans.

9. Deliver the item

Provide instructions, warranty information, safety information, contact details, and any applicable return or service policies.

10. Create proof of delivery

Document the actual delivery using the method required for direct delivery, shipping, or facility delivery.

11. Submit the claim

Use the correct item description, HCPCS code, modifiers, diagnosis information, supplier data, and ordering-practitioner information.

12. Retain and update records

Maintain the required documentation and obtain new orders or continued-need documentation when the applicable policy requires it.

Recommended printable form structure

Instead of one long form, provide four clearly labeled downloads or print sections.

Form 1: Standard Written Order

Field
Beneficiary name
MBI or payer member ID
Date of birth
Item description
Manufacturer/model
Quantity
Accessories/supplies
Diagnosis
Clinical goal
Length of need when applicable
Order date
Treating practitioner name
NPI
Telephone/fax
Practitioner signature
Signature date

Form 2: Letter of Medical Necessity worksheet

Field
Diagnosis and date of onset
Functional limitation
Objective findings
Relevant treatment history
Requested item
Why the item is needed
Why alternatives are inadequate
Rehabilitation plan
Expected measurable benefit
Anticipated duration
Supporting records attached
Practitioner certification

Form 3: Patient authorization and Assignment of Benefits

Separate section
Patient and insurer identification
Assignment-of-benefits acknowledgment
Claim-submission acknowledgment
Financial-responsibility terms
Privacy-notice acknowledgment
Patient or representative signature
Representative authority and relationship
Date

Form 4: Proof of Delivery

Field
Beneficiary
Delivery address
Item description
Quantity
Serial number if applicable
Delivery method
Date delivered or shipped
Recipient/designee name
Recipient/designee signature for direct delivery
Relationship to beneficiary
Carrier
Tracking number
Supplier representative

Frequently asked questions

Is a prescription the same as a letter of medical necessity?

No. A prescription identifies the item ordered. An LMN explains the patient-specific clinical rationale. Some cases need both, but an LMN does not replace a complete order.

Does an assignment of benefits guarantee insurance payment?

No. It may allow direct payment to the supplier, but the claim must still meet eligibility, coverage, coding, documentation, supplier, and delivery requirements.

Can a letter of medical necessity replace the medical record?

Not for Medicare. Supplier-generated records and letters of medical necessity must match the treating practitioner’s medical record.

Does Medicare still require a Certificate of Medical Necessity?

CMS discontinued CMNs and DIFs for claims with dates of service on or after January 1, 2023. Current orders and medical-record requirements still apply.

Must the practitioner sign by hand?

No. A valid electronic signature may be acceptable. Signature and date stamps are generally not accepted for Medicare documentation.

Is “99 months” always the correct length of need?

No. Do not present “99” as a universal rule. Length-of-need fields and coding conventions depend on the payer, item, claim system, and clinical circumstances.

Is the patient’s Social Security number required?

Avoid collecting an SSN on a general public form unless the specific payer or law demonstrably requires it. Use an MBI, member ID, or claim number whenever appropriate.

Is a patient signature always required for shipped home deliveries?

Not necessarily. Direct delivery and delivery through a commercial shipping service have different proof-of-delivery requirements. Shipping and tracking documentation may support mailed delivery.

Can the patient sign proof of delivery before the item ships?

No. Proof of delivery is intended to document that delivery has occurred.

Is an AOB the same as a HIPAA authorization?

No. An AOB concerns payment direction. A HIPAA authorization concerns the use or disclosure of health information when an authorization is required.

Does the patient-responsibility clause replace a Medicare ABN?

No. When a valid ABN is required, the supplier must use the current official CMS-R-131 process.

Is a prescribed device automatically covered?

No. A valid prescription establishes the practitioner’s order but does not establish payer coverage.

Is an over-the-counter device ineligible for reimbursement?

OTC availability alone does not determine benefit coverage. The actual payer policy, item classification, diagnosis, supplier status, and supporting records for claim adjudication.

Will Medicare cover any NMES unit prescribed for weakness?

No. Medicare’s national muscle-atrophy coverage is limited to disuse atrophy with intact nerve supply, subject to the complete applicable requirements.

Will Medicare cover TENS for chronic low-back pain?

Routine coverage should not be assumed. Medicare’s national policy restricted that indication to qualifying approved research studies during a defined period.

Can Balego guarantee insurance reimbursement?

No supplier can guarantee a payer’s final adjudication. We can provide product specifications, manuals, invoices, and product-selection support through the Balego contact page.

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