HCPCS code A9999 – Unlisted DME supply or accessory

Key takeaways

HCPCS code A9999 covers DME supplies and accessories with no specific HCPCS code, so it is a last resort rather than a catch-all.

Medicare has no fixed fee for A9999, and the DME MAC prices each claim individually, usually from the supplier’s invoice.

Billing A9999 when a specific code exists gets the claim denied, so search the current HCPCS file and quarterly updates first.

Use GA, GY or GZ where the ABN or expected-denial situation applies, and KX only where an LCD requires it.

Claims software such as Pabau pre-fills claims from the patient record, checks required fields before Send, and submits US claims through Claim.MD.

HCPCS code A9999 is the last stop for unlisted DME supplies

HCPCS code A9999 is the Level II code for a miscellaneous DME supply or accessory, not otherwise specified. It applies only when no other HCPCS code describes the durable medical equipment (DME) supply or accessory you provided. CMS maintains the code set, and the “not otherwise specified” (NOS) label tells the payer the item has no identifier of its own.

Payers read that label as a request for individual review. So every A9999 line needs paperwork that a coded item never would. If you’re still learning how medical billing works, treat A9999 as a manual claim from start to finish.

The code is active, and CMS reviews it in each annual HCPCS update. There is no fixed Medicare payment rate attached to it, because every item billed under it is different.

What A9999 covers, and where it never belongs

A9999 covers DME supplies and accessories that have no specific HCPCS Level II code. The key words are “not otherwise specified.” If CMS has created a dedicated code for an item, that code must be used, even when A9999 feels quicker.

Nebulizer accessories, standard wheelchair cushions and crutch accessories all have codes of their own. So check the current CMS HCPCS annual code file before you reach for A9999.

• May fit A9999: new accessories CMS hasn’t coded yet, DME components made to an individual specification, and low-volume supplies awaiting a future HCPCS update.
• Never fits A9999: any item with a code in this year’s CMS file. The same goes for items an LCD assigns to another code, and supplies billed under named A-, E- or K-series codes.

Neighboring codes decide whether A9999 is right at all

Three codes cause most of the confusion around A9999: A9900, A9270, and the named E-series accessory codes. Each one answers a different billing question.

The A9270 split matters most at audit. A9270 tells the payer you already know the item is not a benefit. A9999 says the item may be covered but lacks a code, so it goes to individual review rather than an automatic denial. Mixing the two up leads to wrong payment decisions and compliance exposure.

Run the four checks below in order, and the first “yes” settles which code goes on the claim.

Medicare prices each A9999 claim by hand

Medicare pays no fixed rate for HCPCS code A9999. Instead, the claim is priced by the DME MAC through individual consideration, usually with reference to the supplier’s invoice. That makes these claims far heavier on paperwork than coded DME.

Good claims software for suppliers won’t pick the code for you. It does keep the required claim fields complete before the claim is sent.

Under Part B, the DME MAC asks three questions. Is the item medically necessary? Does it fall within a benefit category? And is there a valid reason no specific code applies? Expect a request for additional documentation on most A9999 claims.

Here’s how a well-built A9999 claim moves from order to payment:

1. Confirm no specific code exists. Search the current HCPCS Level II file, the quarterly updates and your DME MAC’s LCDs.
2. Get the written order. It identifies the supply or accessory and its medical purpose, and it anchors the claim.
3. Attach the cost invoice. The DME MAC uses it to price the item, so a missing invoice leaves it no basis for payment.
4. Add the medical necessity statement. The treating clinician explains why the item is needed and why a coded item won’t do.
5. Apply a modifier where one applies. GA, GY or GZ tells the DME MAC what you expect on coverage.
6. Submit, then answer the review. Expect a documentation request before the claim is priced or denied.

The documentation file a DME MAC expects to see

A9999 claims carry a heavier documentation load, because there is no LCD coverage checklist to validate them against. Sound medical billing compliance means these records sit in the patient file before the claim goes out.

• Written order: names the item, the quantity and the order date, with the treating practitioner’s name, NPI and signature.
• Itemized description: a plain-English narrative in Item 19 of the CMS-1500, or the matching field on the 837P. A generic label like “DME supply” gets the claim returned.
• Cost invoice from the manufacturer or distributor: required so the DME MAC can price the item.
• Medical necessity statement: written by the treating clinician, explaining why this patient needs the item and why no coded item is a fit.
• Proof of your code search: a dated record of the HCPCS file search, which protects you if the claim is audited.

Modifiers on A9999 follow the ABN and the coverage facts

Use GA, GY or GZ where the ABN or expected-denial situation applies, and KX only where an LCD requires it. A9999 has no coverage policy of its own, so KX rarely fits.

Whichever modifier you choose has to sit on the claim line, not only in the notes. That is one reason a clean claim review before each batch pays off.

Only append GY when you are certain the item is statutorily excluded. GY marks the item as statutorily non-covered, so Medicare will deny it and the patient may be billed. GA works differently, because it flags a possibly covered item with a signed ABN on file. When coverage is in doubt, issue an ABN and use GA.

There is no A9999 fee schedule amount to look up

HCPCS code A9999 does not appear in the DMEPOS fee schedule with a set payment rate. The items billed under it differ too much for one price. When payment happens, the DME MAC sets it case by case from the supplier’s invoice.

Medicaid rates vary by state plan. Some states copy Medicare’s invoice-based approach, while others cap miscellaneous DME at a maximum allowable. Commercial payers follow their own contracts, so check the contract and any prior authorization rule before you assume a rate.

The AAPC HCPCS code lookup and PGM Billing’s HCPCS lookup tool confirm the code’s current status. Neither returns a Medicare allowable for A9999, because none is published.

Why A9999 claims get denied, and how to appeal

A9999 denials cluster around a predictable handful of causes. Strong denial management catches most of them before submission, rather than at redetermination.

• A specific code existed: the DME MAC finds a current HCPCS code that describes the item billed under A9999.
• A thin item description: generic wording in Item 19 triggers a return. Name the item, its function and why the patient needs it.
• No cost invoice: without one, the DME MAC has no basis to price the item and denies it pending documentation.
• No ABN when coverage was uncertain: without an ABN and the GA modifier, the supplier usually carries the loss if Medicare denies.
• Medical necessity not documented: no clinician statement links the item to a diagnosis and a functional need.
• GY on a possibly covered item: GY marks the item as statutorily non-covered, so Medicare will deny it and the patient may be billed.

How to appeal an A9999 denial

A9999 appeals follow the standard five-level Medicare pathway. The difference is the packet, which needs more supporting material at every level than a typical appeal.

1. Redetermination (Level 1): file with the DME MAC within 120 days of the initial denial. Attach the invoice, the order, the Item 19 narrative and the necessity statement. Explain why no specific code applies, citing the date of your HCPCS file search.
2. Reconsideration (Level 2): file with the Qualified Independent Contractor (QIC) within 180 days if the DME MAC upholds the denial. The QIC reviews the claim fresh, so send the full file again plus any new clinical evidence.
3. ALJ hearing (Level 3): available when the amount in controversy meets the annual threshold CMS sets. File within 60 days of the QIC decision.
4. Medicare Appeals Council (Level 4): file within 60 days of the ALJ decision. The Council reviews the record and rarely holds hearings for DME denials.
5. Federal District Court (Level 5): available when the amount in controversy meets the judicial review threshold. Miscellaneous DME supply claims rarely get this far.

Two medical billing denial codes come up often on A9999 remittances. CO-4 means the procedure code is inconsistent with the modifier used, or a required modifier is missing. CO-50 means the payer judged the item not medically necessary.

CO-4 requires correcting or adding the modifier and resubmitting. CO-50 requires stronger medical necessity documentation.

Each payer handles A9999 its own way

A9999 coverage varies widely by payer. If you assume Medicare’s invoice-based approach applies everywhere, commercial claims get processed wrongly and Medicaid claims start coming back denied.

Commercial and Medicare Advantage plans often require prior authorization for NOS HCPCS codes. Many also route any miscellaneous-code claim to manual review. The CGS Medicare coding verification guidance gives DME suppliers direction for the CGS jurisdiction. Suppliers elsewhere should check with their own DME MAC.

Before you submit an A9999 claim, run this checklist

A missing piece on an A9999 claim usually means a return or a denial. So tick off each of these before the claim leaves your desk:

• You searched the current HCPCS file and quarterly updates, and recorded the search date.
• A9900, A9270 and the named A-, E- and K-series codes have been ruled out.
• The written order names the item, the quantity and the treating practitioner.
• The manufacturer or distributor invoice is attached to the claim.
• Item 19 names the item, its manufacturer, its model and what it does.
• The medical necessity statement explains why no coded item will do.
• GA, GY or GZ is on the claim line where the ABN or coverage situation calls for it.
• Prior authorization is on file wherever the payer requires it.

How Pabau keeps A9999 claims complete before they go out

An A9999 claim depends on details spread across the order, the invoice and the patient file. Often a biller copies them into the claim form by hand, then checks every field a second time.

Pabau, the practice management platform we build, pre-fills the claim from the patient record instead. Its CPT and HCPCS code lookup libraries sit on the claim screen, and the Send button stays locked until required claim fields are complete.

In the US, claims go out through Claim.MD, with eligibility checks, remittance posting and claim tracking in the same workflow. Pabau won’t choose the code or the modifier for you. It keeps the claim complete, so your team spends less time chasing returns.

Catch missing claim fields before you send

Pabau pre-fills claims from the patient record, offers CPT and HCPCS code lookup, and checks required fields before Send. US claims go through Claim.MD with eligibility checks, remittance posting and claim tracking.

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Conclusion

Treat A9999 as a last resort you have to prove. Once you can show the code search, the order, the invoice and the necessity statement, an individual review has little left to question.

The trade-off is time. Each A9999 claim takes longer to build than a coded one, and a code released mid-year can undo that work. So recheck the HCPCS file before every A9999 claim, especially in the weeks after a quarterly update.

Book a demo to see how Pabau pre-fills claims and checks required fields before your next DME claim goes out.

Continue your research

Need to understand how DME denials escalate? Denial management in healthcare covers the full redetermination pathway and strategies for reducing write-off rates.

Wondering how the HCPCS modifier rules affect your bottom line? Clean claim submission breaks down the modifier and documentation requirements that determine first-pass acceptance rates.

Looking for the billing compliance framework behind NOS codes? Medical billing compliance outlines the audit risk areas that apply when miscellaneous codes are used frequently.

Weighing A9999 against its sister code? HCPCS code A9900 explains when a supply counts as a component of another billed item.

Frequently asked questions