DME billing services for suppliers and DME-owning practices

The DME codes we bill most

Modifiers that matter

Payer rules to know

Top denials in dme billing services for suppliers and dme-owning practices

Who pays DME claims, and which DME MAC gets yours?

Medicare pays DMEPOS (durable medical equipment, prosthetics, orthotics and supplies) claims through four DME MACs, one per jurisdiction. Noridian runs Jurisdictions A and D and CGS runs B and C, according to the contract pages on CMS.gov. Claims go on the CMS-1500 to the contractor for the patient's state.

Chapter 20 of the Medicare Claims Processing Manual says DMEPOS pays at the fee schedule amount for the state where the patient keeps a permanent residence.

What goes on a standard written order, and when must it exist?

Every DMEPOS claim needs a standard written order (SWO) from the treating practitioner. 42 CFR 410.38(d)(1) lists six required elements: the patient's name or MBI, a general description of the item, the quantity if it applies, the order date, the practitioner's name or NPI, and the practitioner's signature.

The DME MAC standard documentation article (A55426) says signature and date stamps are not allowed, and a claim for an item that does not meet the order rules must carry the EY modifier.

Timing depends on the item. Under 42 CFR 410.38(d)(1)(ii), the order must reach the supplier before claim submission for most items, but before delivery for power mobility devices and for items on the Required Face-to-Face Encounter and Written Order Prior to Delivery List (WOPD list).

For those listed items, the practitioner must also document an in-person or telehealth face-to-face encounter within the 6 months before the order date. The note must show the findings that led to the order.

CMS's order requirements page says the list reaches 105 items as of October 28, 2026. The PDF CMS posts includes oxygen codes E0424, E0431, E0434, E0439, E1390, E1391, E1392 and K0738. CPAP code E0601 is not on it.

• New order needed: initial purchases or rentals, any change in the order such as quantity, a replacement item, and a change of supplier when the new supplier cannot get the old order.
• Supplier is also the practitioner: no SWO is required, but the chart must still contain every SWO element.

What proof of delivery do Medicare auditors expect?

Proof of delivery is a signed record that the patient received the exact item you billed. 42 CFR 424.57(c)(12) makes the supplier responsible for delivery and for keeping this proof, and the DME MAC article says POD and claim records must be kept for 7 years from the date of service.

For delivery by the supplier, the signed and dated slip needs six things: patient name, delivery address, a description of the item, quantity, delivery date and the signature of the patient or a designee. The date of delivery is the date of service unless an LCD says otherwise.

For shipped items, the POD is the supplier's invoice linked to the carrier's tracking record by a package or invoice number. The supplier and anyone with a financial interest in the delivery cannot sign as the patient's designee. A claim with no acceptable POD is denied and an overpayment is requested.

How do capped rental, the 13-month rule and the 36-month oxygen rental work?

Capped rental items are paid by the month and then become the patient's property. Under 42 CFR 414.229(f), payment for these items runs for no longer than 13 months of continuous use, and the supplier must transfer title on the first day after the 13th paid month. The supplier that bills month one must keep supplying through month 13 unless the patient moves away or chooses another supplier.

Oxygen equipment is different. 42 CFR 414.226(a)(1) pays monthly rental for no more than 36 months of continuous use, and the supplier that furnishes the 36th month must keep furnishing equipment for the rest of its reasonable useful lifetime. The oxygen policy article (A52514) sets that lifetime at 5 years from the first date of service.

Break-in-need matters. The oxygen article says a new 36-month period starts only after at least 60 days without need plus the rest of the month, with new medical necessity documented. Chapter 20 uses the same 60-day test for capped rental.

Report the rental status with the RR modifier on rentals, NU on new purchased equipment and UE on used purchased equipment. Chapter 20 also lists KI and KJ for later rental months, so check what your DME MAC wants on a given code.

Which modifiers decide whether a DME claim pays: KX, GA, GY, GZ?

KX says the LCD requirements are met, and GA, GY and GZ say they are not. The PAP and oxygen policy articles state that a line billed without one of these modifiers is rejected as missing information, so the choice is never optional.

• KX: every coverage criterion in the LCD is met and documented in the supplier's file. Do not add it on a hunch.
• GA: payment is expected to be denied as not reasonable and necessary, and a properly executed ABN is on file.
• GZ: the same expected denial, but no valid ABN is on file, so the supplier carries the liability.
• GY: the item or service is statutorily excluded from the Medicare benefit.
• N1, N2, N3: for initial oxygen claims and new 36-month periods with dates of service on or after April 1, 2023, these replace KX and name the oxygen group the patient qualifies under. A KX on such a line is rejected as an invalid modifier.

The upgrade rule in Chapter 20 is easy to miss. When a patient chooses a more expensive item than the one that is medically necessary, bill two lines on one claim in order. Line 1 is the upgraded item with GA (ABN signed) or GZ (no ABN). Line 2 is the covered item with GK. List the upgrade features in item 19 of the CMS-1500 or the electronic equivalent.

What does the CPAP adherence rule require, and what happens at month four?

LCD L33718 defines adherence as use of at least 4 hours per night on 70 percent of nights during a consecutive 30-day period within the first 3 months, and it requires an in-person re-evaluation by the treating practitioner between the 31st and 91st day that documents improved symptoms.

For months one to three, add KX to E0601 or E0470 and the accessories only when the initial coverage criteria are met. From month four, KX needs both the initial and the continued coverage criteria. Without that information the supplier may submit with GA or GZ, or hold the claim.

If the re-evaluation happens after day 91 but still shows benefit and adherence, coverage resumes from the date of that visit. A patient who fails the 12-week trial must have a new in-person evaluation and a repeat facility-based sleep test to re-qualify.

The LCD also says an E0471 is not reasonable and necessary when the primary diagnosis is obstructive sleep apnea. The sleep study side is on our sleep medicine billing page.

Which DME items need prior authorization, and how long does CMS take?

Power mobility devices and other items on the Required Prior Authorization List need a provisional affirmation from the DME MAC before delivery, or the claim is denied. 42 CFR 414.234 makes this a condition of payment, and the request must include the written order, relevant medical record information and the supplier's own documentation.

CMS says that since January 1, 2025 standard requests get a decision within 7 calendar days, and expedited requests within 2 business days. An expedited request must show that waiting could seriously jeopardize life, health or ability to regain function.

The list CMS updated on July 29, 2026 includes power wheelchair code K0813, air fluidized bed E0194, manual wheelchair K0005, pneumatic compression devices E0651 and E0652, lower limb prostheses and many orthoses. The bed, the manual chair and four orthosis codes begin nationwide on October 28, 2026.

A supplier that reaches a 90 percent payable-claim rate can be exempt, a process CMS began on June 1, 2026 under rule CMS-1828-F. CMS also lists a probationary process for newly enrolled suppliers from October 15, 2026.

Where does competitive bidding stand now?

The next competitive bidding round has not started, according to CMS's fact sheet last updated December 8, 2025. It lists target dates only: bidding in late summer or early fall 2026, contracts announced in late summer or early fall 2027, and contracts in effect no later than January 1, 2028.

The seven categories are class II continuous glucose monitors and insulin pumps, urological and ostomy supplies, hydrophilic urinary catheters, and off-the-shelf back, knee and upper extremity braces, all in a nationwide remote item delivery program.

CGM billing itself is on our endocrinology billing page. The CMS pages do not confirm whether the bid window has opened, so check CMS before relying on the dates.

What supplier standards and accreditation does a DME supplier need?

A DME supplier must meet the standards in 42 CFR 424.57(c) to hold Medicare billing privileges. The standards include keeping proof of delivery, answering patient complaints, and repairing or replacing rented items at no charge, along with accreditation and a surety bond.

Do CMN and DIF forms still exist?

No. Chapter 20 of the Medicare Claims Processing Manual says suppliers no longer need to submit certificate of medical necessity (CMN) or DME information form (DIF) documents for dates of service on or after January 1, 2023. Claims that arrive with the forms attached are rejected and returned.

How do appeals and filing limits work for DME?

A DME claim must be filed within 1 calendar year after the date of service under 42 CFR 424.44(a)(1). A redetermination request is due within 120 calendar days of receiving the initial determination under 42 CFR 405.942(a), and receipt is presumed 5 days after the notice date.

Related items live on sibling pages: therapeutic shoes and inserts are covered on podiatry billing, the clinical side of home oxygen on pulmonology billing, and equipment ordered during a home health episode on home health billing.

How we handle DME billing

We follow each rental from order to last paid month. Before a claim goes out we check the SWO elements, the face-to-face date against the order date, the POD and the LCD criteria for the product, then choose KX, GA, GY, GZ or N1 to N3 to match what the chart shows.

To have us review your DME denials, book a call.