HCPCS Code A4931: Oral thermometer, reusable, any type, each

Key Takeaways

HCPCS Code A4931 describes a reusable oral thermometer, any type, billed per each unit, and CMS classifies it under Dialysis Equipment and Supplies within the A4653-A4932 ESRD range.

A4931 carries a Medicare pricing indicator of “00” (not separately priced) and sits on the CMS ESRD PPS Consolidated Billing list, so it is bundled into the ESRD facility’s composite/PPS payment rather than paid on a stand-alone MAC fee schedule.

A4931 sits on the CMS ESRD PPS Consolidated Billing list under the sub-heading for supplies “not payable to DME suppliers.” That’s a longer, separate list from the roughly nine ESRD-bundled codes where modifier AY restores separate DME-supplier payment, and A4931 isn’t one of them, so a DME supplier or home health agency has no AY-modifier route to separate payment for it.

Pabau’s claims management software helps billing teams flag ESRD-bundled codes like A4931 before submission, reducing the risk of a claim rejected because it should have gone through the ESRD facility instead of the MAC.

HCPCS Code A4931 describes an oral thermometer, reusable, of any type, billed per each unit. According to the Centers for Medicare and Medicaid Services (CMS) HCPCS Level II coding system, CMS places the code within the “Dialysis Equipment and Supplies” section of the HCPCS Level II A-code range (A4653-A4932), not the general open-market DME supply category.

“Any type” in the descriptor means the code applies regardless of thermometer technology, covering digital oral, electronic oral, and similar reusable designs.

That ESRD classification carries a specific billing consequence covered in detail later in this guide: A4931 carries a Medicare pricing indicator of “00” (not separately priced) and sits on the CMS ESRD PPS Consolidated Billing list. It does not behave like a typical stand-alone DMEPOS fee-schedule code with its own MAC-locality allowed amount.

The code is billed on a per-unit (“each”) basis. When a patient receives one reusable oral thermometer, one unit of A4931 is reported. For a patient on maintenance dialysis, the ESRD facility is the primary party Medicare looks to for payment, since the item is bundled into the facility’s ESRD PPS composite rate.

Non-facility DME suppliers and home health agencies may furnish the item, but cannot submit a stand-alone Medicare Part B claim for it. A4931 sits on the ESRD PPS Consolidated Billing list under the sub-heading for supplies not payable to DME suppliers, so no modifier, including AY, opens a separate-payment route for this biller type.

Physicians and outpatient hospitals do not typically bill A4931 independently at all. Understanding the billing context matters: practice management workflows that handle DME claims need to capture the correct product category, billed unit, and supplier eligibility before submission.

A4931 code details and attributes

The table below summarizes the key attributes for A4931 as maintained in the CMS HCPCS Level II file. These details determine how the code is positioned on a claim form and which payer rules apply.

Effective dates are published annually in the CMS HCPCS Level II release. Before submitting claims for any supply code, confirm the code remains active for the date of service using the AAPC HCPCS code search. Retired or revised codes submitted on claims return a denial without payment, and resubmission windows are limited.

Billing teams that manage multiple supply codes benefit from claims management software that flags code status changes at the point of claim creation, rather than discovering the issue after a denial.

Medicare fee schedule for A4931

A4931 does not have its own locality-based Medicare Physician Fee Schedule or DME fee schedule amount the way most open-market DME supply codes do. CMS assigns the code a pricing indicator of “00,” meaning it is not separately priced on the standard fee schedule.

That is because A4931 sits on the CMS ESRD PPS Consolidated Billing list. When the thermometer is furnished to a maintenance dialysis patient in connection with their dialysis care, it is bundled into the ESRD facility’s composite rate under the ESRD Prospective Payment System (PPS), rather than billed line-by-line to the MAC.

Always verify the code’s current consolidated billing status against the annual CMS ESRD PPS Consolidated Billing list before assuming any other pricing framework applies.

Because A4931 is not separately priced in the bundled ESRD context, quoting a locality-based dollar figure as the “expected reimbursement” for an A4931 claim is incorrect.

Unlike the short list of ESRD-bundled codes where modifier AY restores a DME fee-schedule amount, A4931 carries no such fee-schedule fallback for a non-facility supplier. It stays on the ESRD facility’s bundled claim regardless of the modifier appended. Confirm the code’s consolidated billing status against current CMS sources before submitting.

Practices managing ESRD-bundled supply codes alongside standard DME billing need a system that flags which framework applies before a claim goes out. Effective practice management tools that save billing time do this automatically at the point of claim generation.

Medicare and Medicaid coverage for A4931

Medicare Part B covers A4931 when it is medically necessary in connection with a beneficiary’s dialysis care, but the payment pathway runs through ESRD PPS consolidated billing rather than the standard DME medical supplies benefit.

For a patient on maintenance dialysis, the ESRD facility’s bundled composite payment already includes the reusable oral thermometer. Medicare does not make a separate Part B payment to a supplier for it under ordinary circumstances.

Key Medicare coverage conditions for A4931:

• The item must be furnished in connection with the beneficiary’s dialysis care to fall under ESRD PPS bundling
• For a maintenance dialysis patient, the ESRD facility (not a non-facility DME supplier) looks to Medicare for payment, since the supply is bundled into the facility’s composite/PPS rate
• A4931 appears on the CMS ESRD PPS Consolidated Billing list under the sub-heading for codes not payable to DME suppliers, so a non-facility supplier or home health agency cannot submit a stand-alone claim to the MAC for it under any modifier
• Modifier AY restores separate DME-supplier payment only for the short list of ESRD-bundled codes CMS designates for Consolidated Billing Edits (for example A4216, A4217, A4218, A4450, A4452, A6215, A6216, A6402, and E0210). A4931 is not on that list, so AY does not create a separate-payment pathway here
• A genuine “furnished for a reason unrelated to ESRD” scenario for an item like this is billed through the ESRD facility’s own claim, not a non-facility supplier’s claim to the MAC

Medicaid coverage for A4931 varies by state and is generally assessed independently of Medicare’s ESRD PPS consolidated billing rules, since state Medicaid programs run their own DME benefit and fee schedules. Some states cover reusable oral thermometers furnished outside a bundled dialysis-facility payment. Others don’t include them on the covered supply list at all.

Always check the applicable state’s Medicaid fee schedule and coverage policy. For a dual-eligible ESRD patient, confirm separately whether the claim should route through Medicare’s consolidated billing first.

Private payers and commercial insurance plans have their own policies. Some follow Medicare’s coverage criteria by reference. Others apply their own prior authorization requirements or exclusions for low-cost supplies. Review the payer’s provider manual or call their provider line before assuming coverage aligns with Medicare policy.

Managing coverage determinations across multiple payers is one of the more time-consuming parts of DME billing. Teams using HIPAA-compliant practice management platforms can store payer-specific coverage rules alongside patient records, reducing lookup time before each claim run.

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A4931 billing guidelines and documentation requirements

Getting A4931 paid requires more than selecting the right code. The claim must reflect the correct billing pathway: bundled under the ESRD facility’s consolidated billing, since a stand-alone AY-exception claim is not available to a non-facility supplier for this code. It must also carry appropriate documentation. The billing sequence below reflects the correct order of operations.

1. Obtain a written order. An eligible prescriber must issue a written order for the reusable oral thermometer before it’s supplied, documenting medical necessity and whether it’s furnished in connection with dialysis care.
2. Confirm the billing pathway. For maintenance-dialysis patients, A4931 is on the CMS ESRD PPS Consolidated Billing list and belongs on the ESRD facility’s bundled claim — not a stand-alone MAC submission from a non-facility supplier.
3. Verify the correct party’s enrollment. Confirm the ESRD facility is Medicare-enrolled and submits the bundled claim. A4931 bills through the facility, not a non-facility DME supplier, since no modifier opens a separate-payment pathway to that biller type. Claims from non-enrolled entities are rejected at the clearinghouse.
4. Select the correct code. Bill A4931 at one unit per thermometer. Don’t use it for a non-contact or rectal thermometer — those map to adjacent A49xx codes.
5. Don’t rely on modifier AY. A4931 sits under the “not payable to DME suppliers” sub-heading — a separate, longer list from the ~9 ESRD-bundled codes where AY actually restores DME-supplier payment. A4931 isn’t one of them, so AY won’t make a non-facility claim payable. NU, UE, RR, KX, and GY don’t apply either while the code is ESRD-bundled.
6. Submit on the correct claim form. The ESRD facility uses its institutional claim form. A non-facility DME supplier or home health agency shouldn’t submit a CMS-1500 (or 837P) for A4931 expecting separate payment.
7. Retain supporting documentation. Keep the written order, proof of delivery (POD), and any ABN in the patient file per the payer’s retention policy. With no AY route for non-facility suppliers, there’s no separate “unrelated to ESRD” note to retain for this code — any such determination lives on the ESRD facility’s own claim.

Proof of delivery is a frequent audit trigger for DME supply claims. An ABN is required when Medicare coverage is uncertain, to protect the right to collect from the beneficiary if Medicare denies the claim.

Document-heavy workflows like these benefit from digital forms management that captures, timestamps, and stores patient-facing documents alongside the billing record.

Teams looking at broader EHR integration for billing workflows can connect order management directly to claim generation, cutting the manual handoff that often leads to missing or delayed documentation.

HCPCS modifiers commonly used with A4931

Modifiers communicate additional claim context to the payer, but A4931’s modifier framework is dictated by its ESRD PPS consolidated billing status, not by the ordinary open-market DME modifier set.

Applying NU, UE, RR, KX, or GY to a bundled A4931 claim is a common and avoidable error, and so is assuming modifier AY opens separate payment here. AY genuinely restores separate DME-supplier payment only for a short, specific list of ESRD-bundled codes, and A4931 is not on that list.

No modifier, including AY, converts A4931 into a stand-alone MAC claim for a non-facility DME supplier or home health agency. CMS’s Consolidated Billing list places A4931 under the sub-heading for codes not payable to DME suppliers.

That’s distinct from the short list of codes (roughly nine, including A4216, A4217, A4218, A4450, A4452, A6215, A6216, A6402, and E0210) where AY genuinely restores separate DME-supplier payment.

A billing team that sees AY appended to a DME supplier’s A4931 claim should treat it as an error, not a legitimate exception. Any genuine furnishing of an item like this unrelated to ESRD treatment is billed on the ESRD facility’s own claim, not a supplier’s claim to the MAC.

This classification has been stable for years: CMS Transmittal 2134 (CR 7064) separates the “not payable to DME suppliers” list from the shorter Consolidated Billing Edits list where AY applies.

Modifier misapplication isn’t unique to A4931. CPT code 01829 carries its own base-unit and time-reporting rules that trip up billers in much the same way.

Modifier accuracy is a core part of managing medical documentation and billing records effectively. A billing platform that enforces modifier rules at the code level prevents the most common submission errors before they reach the payer.

Related HCPCS codes: A4930, A4932, and adjacent supply codes

A4931 sits within the A49xx thermometer series. Selecting the wrong code from this group is an easy mistake when building claim templates, particularly for practices that supply multiple thermometer types. The table below clarifies the distinctions.

The most common coding error in this group is billing A4931 when A4932 (rectal thermometer) was actually supplied, or vice versa. Both share identical billing structure (reusable, any type, each) but differ in route. The route documented in the written order and proof of delivery must match the code submitted.

Note that A4930 describes sterile gloves, not a thermometer, despite its position adjacent to A4931 in the code series.

Practices managing a range of DME and ESRD supply codes benefit from a reference system or billing platform that maps each supplied item to its correct HCPCS code, and flags which codes are subject to ESRD PPS consolidated billing, before the claim is generated.

Coding by memory across a large supply catalog is where substitution errors occur. The same risk shows up elsewhere in the HCPCS supply catalog, from confusing a breast-pump supply code like A4283 or A4285 with a similar-looking code to misreading a modifier rule on an unrelated procedure code.

For a broader look at how HCPCS Level II codes are structured and maintained, the NLM HCPCS Level II API provides programmatic access to code descriptions, which can be integrated into billing workflows for real-time code validation.

How Pabau supports DME and medical supply billing

No competitor page covering A4931 addresses the practice management side of HCPCS supply billing, and that matters. The billing workflow for supply codes like A4931 involves more steps than a standard office visit claim: written orders, proof of delivery, modifier selection, payer-specific coverage rules, and documentation retention.

Handling these steps manually across a high-volume supply catalog creates the conditions for the exact errors that generate denials.

Pabau’s claims management software helps DME suppliers, physical therapy practices, and general practices manage HCPCS code claims with fewer manual steps. Features relevant to A4931 billing include:

• Consolidated-billing flags: Flag ESRD-bundled codes like A4931 at the point of claim creation, and surface the AY-modifier requirement only for the narrow set of claims genuinely unrelated to ESRD treatment, so billers don’t default to the standard DME modifier set out of habit.
• Documentation linking: Connect written orders, proof of delivery, and ABNs directly to the claim record, so auditors and payer reviewers see supporting documentation in one place.
• Payer-specific rule sets: Store Medicare and Medicaid coverage criteria alongside the patient account, with alerts when coverage conditions are not met before submission.
• Claim status tracking: Monitor claim status across multiple payers in real time, flagging denials for review before they age past timely filing limits.

Practices that handle both clinical services and DME supply billing often run two separate workflows, one for procedures and one for supplies, because their practice management platform does not support both. Pabau handles both under one system, removing the reconciliation step between clinical records and supply billing.

For practices focused on HIPAA-compliant record retention for DME claims, Pabau’s documentation tools align with the storage requirements that Medicare audits typically reference. See how patient data security and compliance tools support this need across clinical and billing records.

Conclusion

A4931 claims fail most often because the biller treats it like an ordinary open-market DME supply code, or assumes modifier AY can unlock separate payment the way it does for a handful of other ESRD-bundled codes.

A4931 sits on the CMS Consolidated Billing list under the sub-heading for codes not payable to DME suppliers, so for a non-facility supplier or home health agency it is essentially never separately payable, under any modifier.

Confirming the billing pathway matters more than any other step: the ESRD facility’s bundled claim, not a stand-alone DME claim, before documentation and modifiers even come into play.

Pabau’s claims management software reduces these failure points by enforcing modifier rules, linking documentation to claims, and tracking payer-specific coverage criteria at the point of submission. To see how it handles HCPCS supply billing in practice, book a demo and walk through a live supply code workflow.

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