DME billing doesn’t end when the equipment leaves the warehouse. A hospital bed or oxygen concentrator can generate a claim every month for more than a year, and each one has to carry the right rental modifier, match a valid order, and stay inside the payer’s coverage rules until the rental period caps out. DME credentialing has its own weight, since a supplier can’t bill Medicare at all without accreditation, a surety bond, and enrollment for every location.
Key Takeaways
- Capped rental items bill monthly with the KH, KI, and KJ modifiers for up to 13 months, after which the patient owns the equipment.
- Oxygen equipment pays for 36 months of rental, and the supplier stays responsible for it for up to five years.
- Medicare dropped Certificates of Medical Necessity in 2023, so the standard written order and the medical record now carry that weight.
- Items on Medicare’s required prior authorization list, like power wheelchairs, need approval before delivery.
- Medicare DMEPOS enrollment requires accreditation, a surety bond, and compliance with 30 supplier standards for each location.
How DME Billing Works
DME claims use HCPCS Level II codes, and Medicare processes them through four regional DME Medicare Administrative Contractors based on where the patient lives, not where the supplier is located. Each DME MAC publishes local coverage determinations and policy articles that set the documentation, diagnosis, and frequency rules for each product category, and the Pricing, Data Analysis, and Coding contractor confirms which HCPCS code a specific product falls under.
Rental and purchase modifiers
The payment category decides how an item bills. Inexpensive and routinely purchased items, like walkers and canes, can be bought outright with the NU modifier for new equipment or UE for used. Capped rental items, like hospital beds, standard wheelchairs, and CPAP devices, bill as monthly rentals with the RR modifier. The first month also carries KH, months two and three carry KI, and months four through thirteen carry KJ. After the 13th month, ownership transfers to the patient.
Oxygen works differently. Medicare pays for 36 months of oxygen equipment rental, and the supplier must keep providing the equipment and service for up to five years. Supplies like CPAP masks and diabetic testing strips follow their own replacement schedules, and refills can’t be shipped more than 10 days before the current supply runs out.
Modifiers that show coverage
The KX modifier tells the DME MAC that the policy’s coverage criteria are met and documented. When a supplier expects an item won’t be covered, it gets a signed Advance Beneficiary Notice and bills with GA. GZ means no notice was signed, and the supplier can’t bill the patient if the claim is denied.
Orders, Documentation, and Prior Authorization
Since 2023, Medicare no longer uses Certificates of Medical Necessity or DME Information Forms. Every DMEPOS claim needs a standard written order with the patient’s name, the order date, the item description, the quantity, and the prescriber’s name and signature. For items on CMS’s list, the order also has to be in hand before delivery, and some of those items need a documented face-to-face encounter with the prescriber within six months before the order.
The medical record still has to support coverage. The prescriber’s notes need to show the patient’s condition and why the item is needed, and suppliers can’t create that documentation themselves. When the notes don’t match the policy criteria, the claim fails on audit even if it paid at first.
Medicare also requires prior authorization for items on its required list, including power mobility devices, certain pressure-reducing support surfaces, some orthoses, and lower limb prostheses. Commercial and Medicaid plans keep their own lists, and many route DME through a benefit manager.
Proof of delivery
Every claim needs proof that the item reached the patient. For direct delivery, that means a delivery slip signed by the patient or caregiver, with the date, the item, and the quantity. For shipped items, it means carrier tracking tied to the order. The date of service on the claim is generally the delivery date, so a mismatch between the claim and the delivery record is one of the first things auditors check.
Equipment Tied to Other Specialties
Many DME claims depend on documentation from another provider. CPAP coverage past the first three months depends on a sleep study and a follow-up visit that shows the patient is using the device, which we cover on our sleep study labs page. Home oxygen depends on a qualifying blood gas or oximetry test from the treating physician. Connected devices used for remote patient monitoring are billed by the practice that monitors the data, not by the DME supplier, even when the supplier ships the device.
When the referring provider’s records are incomplete, the supplier’s claim is the one that fails. Suppliers that check those records before delivery, and go back to the prescriber for what’s missing, avoid most of these denials.
Where DME Claims Get Denied
Most DME denials come from a short list of causes. They include a written order missing a required element, an item delivered before the order or prior authorization was in place, proof of delivery that doesn’t match the claim date, the wrong rental month modifier, KX billed without documentation that meets the policy, refills shipped too early, and claims sent to the wrong DME MAC. Many of these get caught before the claim goes out by checking the order, the notes, and the delivery record against the policy for that product.
DME Credentialing and Enrollment
Medicare DMEPOS enrollment
DME suppliers enroll with Medicare through the National Supplier Clearinghouse using the CMS-855S, and each physical location enrolls separately. Before enrollment is approved, a supplier needs accreditation from a CMS-approved accrediting organization, a $50,000 surety bond for each location, state licensure where required, and a passed site visit. Suppliers have to meet all 30 Medicare supplier standards, which cover everything from posted hours and a physical location to complaint handling and liability insurance. DMEPOS suppliers revalidate every three years.
Medicaid and commercial plans
State Medicaid programs and commercial plans credential DME suppliers separately, and many require the same accreditation plus their own insurance and licensing documents. Some plans use exclusive or narrow DME networks, so a supplier may need a contract before it can bill a plan at all. Until each enrollment is approved, that plan’s patients can’t be billed, which is why you can’t bill what you can’t credential.
Payer Contracting for DME Suppliers
Commercial and Medicaid managed care rates for DME are often set as a percentage of the Medicare fee schedule, and rental terms vary more than many suppliers expect. Payer contracting reviews should check rates on the supplier’s highest-volume codes, how the contract handles rental caps and replacement, and whether the plan requires its own authorization process or benefit manager.
DME Billing and Credentialing FAQ
Does Medicare still require a Certificate of Medical Necessity?
No. Medicare stopped using CMNs and DME Information Forms for claims with dates of service on or after January 1, 2023. The standard written order and the prescriber’s medical record now support coverage.
How do capped rental modifiers work?
Capped rental items bill with the RR modifier plus KH for the first month, KI for months two and three, and KJ for months four through thirteen. After 13 months of rental, ownership transfers to the patient.
How long does Medicare pay for oxygen equipment?
Medicare pays for 36 months of oxygen equipment rental. The supplier stays responsible for providing the equipment and service for up to five years.
What does the KX modifier mean on a DME claim?
It tells the DME MAC that the coverage criteria in the policy are met and documented. Billing KX without that documentation is a common audit finding.
What does a DME supplier need to enroll with Medicare?
Accreditation from a CMS-approved organization, a $50,000 surety bond for each location, state licensure where required, a passed site visit, and compliance with all 30 supplier standards. Enrollment goes through the National Supplier Clearinghouse.
Does each DME location need its own enrollment?
Yes. Every location that furnishes DMEPOS needs its own 855S, accreditation, and surety bond, plus an NSC site visit before billing privileges start. Once accreditation is in place, Medwave’s supplier enrollments take around 85 days.
Before a supplier claim goes to the DME MAC, the codes have to match the order on file, which our DME CPT codes guide walks through.
Choosing Medwave as Your DME Billing Partner
Most DME denials trace back to something missing before delivery, like a written order, a prescriber note, or proof of delivery. Medwave checks those first, applies rental month modifiers, and tracks prior authorizations and refill timing. DME billing runs at a 98% clean claim rate with us.
Each supplier location needs its own Medicare DMEPOS enrollment, surety bond, and accreditation. Our credentialing team handles that along with Medicaid and commercial applications, averaging 85 days.
Talk to us below before you file your next 855S.