HCPCS Code A4724: Dialysate solution billing guide

Key Takeaways

HCPCS Code A4724 covers dialysate solution at any dextrose concentration, billed per day for fluid volumes greater than 3,999 cc and up to 4,999 cc.

A4724 falls under the DMEPOS benefit category and is billed to Medicare Part B for patients on home peritoneal dialysis.

Selecting the wrong adjacent code (A4723 or A4725) based on fluid volume is the most common and costly miscoding error for dialysis billing teams.

Pabau’s claims management software helps dialysis and nephrology billing teams track HCPCS supply codes, attach required documentation, and reduce claim denials.

HCPCS Code A4724 covers dialysate solution, any concentration of dextrose, for a daily fluid volume greater than 3,999 cc and up to 4,999 cc, used in peritoneal dialysis. It’s a DMEPOS supply code billed under Medicare Part B, one of seven volume-based codes (A4720 through A4726) that cover the same solution type at different daily volumes.

Selecting the wrong volume code among that range is the most frequent miscoding error in peritoneal dialysis supply billing. Understanding A4724’s exact volume window and how it fits alongside the adjacent codes is the foundation of clean dialysate billing.

HCPCS Code A4724: Definition and official code descriptor

Practice management in nephrology and dialysis settings requires precise supply coding. HCPCS Code A4724 has a specific clinical and billing definition that every billing team should know cold before submitting a claim.

The official long descriptor for HCPCS Code A4724 is: Dialysate solution, any concentration of dextrose, fluid volume greater than 3999 cc, but less than or equal to 4999 cc, for peritoneal dialysis.

In practice, Medicare treats this as a per-day supply unit — each day of dialysate at the covered volume range is billed as one unit — but “per day” is not part of the official CMS descriptor text.

The “any concentration of dextrose” language is intentional. Peritoneal dialysis prescriptions commonly use multiple dextrose concentrations within a single day’s treatment, and A4724 covers all of them as long as the total daily fluid volume falls within the 4,000-4,999 cc window.

HCPCS Code A4724 in context: Peritoneal dialysis supply codes A4720-A4726

HCPCS Code A4724 is one of several adjacent codes covering dialysate solution for peritoneal dialysis. Each code in the A4720-A4726 range is distinguished primarily by daily fluid volume. Picking the wrong one is a systematic error that affects every claim in a billing cycle, not just one-off submissions.

According to the CMS HCPCS overview, Level II codes like A4724 are maintained annually and volume descriptors are authoritative binding definitions.

The boundary between A4723 and HCPCS Code A4724 sits at exactly 3,999 cc. A patient receiving 4,000 cc/day moves out of A4723 territory entirely and into A4724.

Billing staff should verify the prescribed daily volume in the patient’s treatment plan before each claim cycle, not just at initial setup. Prescribed volumes can change as the patient’s clinical condition evolves, and an outdated code selection quietly generates systematic denials.

For teams managing claims management across a nephrology, dialysis, or metabolic health practice, linking supply code selections to the active treatment prescription in the patient record is the most reliable way to stay current as prescriptions change.

Medicare coverage and eligibility for HCPCS Code A4724

HCPCS Code A4724 sits on CMS’s ESRD PPS Consolidated Billing list — the list of items and services bundled into the End-Stage Renal Disease (ESRD) Prospective Payment System (PPS).

Since the ESRD bundled PPS took effect in 2011, dialysate solution codes A4720 through A4726 are folded into the dialysis facility’s single per-treatment bundled payment rather than billed separately to Medicare Part B by a DME supplier.

In practice, a DMEPOS supplier providing dialysate solution for a patient’s home peritoneal dialysis almost always bills the ESRD facility directly, “under arrangement,” instead of submitting a separate claim to the DME MAC. The facility is then responsible for covering that cost out of its bundled ESRD payment from Medicare.

The narrow exception is the AY modifier, which a supplier appends to a claim only when the item being billed is unrelated to the treatment of the patient’s ESRD. Outside that exception, a DME MAC will not separately reimburse A4724 for an ESRD patient’s peritoneal dialysis supplies.

Coverage eligibility generally requires the following conditions to be met, though MAC-specific Local Coverage Determinations (LCDs) govern the precise requirements in each jurisdiction:

• The patient has a confirmed diagnosis of end-stage renal disease (ESRD)
• The treating physician has prescribed home peritoneal dialysis as the modality
• The dialysate solution and volume ordered match the code being billed
• The supplier is Medicare-enrolled as a DMEPOS supplier
• The patient is not in a Medicare-covered inpatient facility where dialysis is included in the facility payment

For the rare AY-modifier claims that fall outside ESRD bundling, coverage determinations are handled at the MAC level. There are two DME MAC contractors nationwide: Noridian, which administers jurisdictions A and D, and CGS, which administers jurisdictions B and C. Each issues its own LCD, so documentation specifics and prior authorization requirements can vary by jurisdiction.

Patient care management workflows that flag whether a supply is billed to the ESRD facility or, in the AY-exception case, separately to the DME MAC at the point of prescription reduce the risk of billing the wrong payer.

A4724 billing guidelines

Billing HCPCS Code A4724 correctly requires more than selecting the right code. Unit definition, frequency, modifier use, and the claim submission path all affect whether a claim processes cleanly on first submission.

Billing unit and frequency

A4724 is billed per day. Each day of dialysate supply at the covered volume range is one unit. For most patients, this per-day unit count feeds into what the supplier bills to the ESRD facility under its bundling arrangement, not a separate DME MAC claim.

Monthly claims typically aggregate the daily units across the service period. Billing teams should confirm the number of treatment days in the billing period against the physician’s prescription and the supplier delivery records before submitting.

Documentation requirements

Required documentation typically includes the following, though MAC-specific LCD requirements should be verified before submission. For guidance on managing medical forms and documentation workflows at your practice, structured digital records make retrieval faster during audits.

• Standard Written Order (SWO): CMS eliminated Certificates of Medical Necessity (CMNs) and DME Information Forms (DIFs) for DMEPOS claims with dates of service on or after January 1, 2023, replacing them with the Standard Written Order. The SWO must specify peritoneal dialysis as the modality and the prescribed dialysate solution and volume — dialysate solution was never among the code categories that used a CMN in the first place
• Treatment plan: confirming the daily volume that determines code selection
• Proof of delivery: supplier delivery records confirming the solution was delivered to the patient’s home, or documentation confirming delivery to the ESRD facility under the billing arrangement
• ESRD diagnosis documentation: supporting the medical necessity of home peritoneal dialysis

Practices using digital forms can attach structured documentation directly to the patient record, making claim preparation and audit response significantly faster. Keeping required documents linked to the relevant billing period is especially important for DMEPOS claims, which are audited at higher rates than most other Medicare claim types.

Modifiers

For most peritoneal dialysis patients, A4724 is billed by the DME supplier to the ESRD facility under the bundled arrangement, not directly to the DME MAC, so standard DMEPOS rental/purchase modifiers generally don’t apply.

The one modifier that matters for this code is AY, appended only when the dialysate solution being billed is unrelated to the treatment of the patient’s ESRD.

When a claim does qualify for the AY exception and is billed to the DME MAC, consult the applicable DME MAC’s supplier manual or the CMS DMEPOS modifiers reference for the current, complete list of required modifiers.

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A4724 fee schedule and reimbursement rates

Dialysate supplies have never been included in the DMEPOS Competitive Bidding Program’s product categories, so competitive bidding rules don’t apply to A4724 at all.

For most peritoneal dialysis patients, A4724 isn’t paid separately by Medicare in the first place — it’s bundled into the ESRD facility’s per-treatment PPS payment, so the supplier’s reimbursement comes from the facility, not from a DME MAC fee schedule.

The CMS DMEPOS fee schedule is only relevant to the rare AY-modifier claim that a supplier bills directly to the DME MAC.

For dialysate supply codes in the A4 group, the key variables that affect the reimbursed amount include:

• MAC locality: for the rare AY-modifier claim billed directly to the DME MAC, payment rates differ by geographic region and are adjusted for local cost factors
• Payment year: fee schedules update annually on January 1. Always confirm the rate applicable to the date of service, not the submission date

Specific dollar rate figures change year to year and vary by MAC region, so billing teams handling an AY-modifier claim should pull the current fee schedule directly from the CMS DMEPOS fee schedule files rather than relying on static references.

For the standard ESRD-bundled scenario, the amount a supplier is paid for dialysate solution is set by its arrangement with the ESRD facility, not by a Medicare fee schedule lookup.

For practices that use procedure code fee schedule management tools, integrating payer fee schedule updates into the billing workflow still helps reduce the risk of submitting AY-modifier claims at outdated rates.

A4724 vs A4723 vs A4725: Choosing the right dialysate code

Volume threshold errors are the most common miscoding problem in peritoneal dialysis supply billing. The three codes billers most often confuse are A4723, HCPCS Code A4724, and A4725. Each covers the same type of supply (dialysate solution, any dextrose concentration) but applies to a specific daily volume range.

According to the AAPC HCPCS code lookup, A4723 covers volumes greater than 2,999 cc and up to 3,999 cc per day, A4724 covers greater than 3,999 cc and up to 4,999 cc per day, and A4725 covers greater than 4,999 cc and up to 5,999 cc per day.

The practical rule: verify the total daily prescribed volume at the start of each billing period. If a patient’s nephrologist has updated the prescription since the last billing review, the code must change.

Using an EHR integration that surfaces the active treatment prescription alongside the billing workflow catches these changes before claims go out. Practices managing medical practice management for multiple home dialysis patients benefit especially from automated prescription-to-code validation.

Common billing errors and how to avoid them

Peritoneal dialysis supply billing has a specific error profile that differs from standard outpatient coding, and it shows up in functional medicine practices managing dialysis patients’ broader chronic care as often as in dedicated nephrology units. Most errors trace back to four recurring problems. This section covers each and the practical fix.

Wrong volume code selected

The most frequent error: HCPCS Code A4724 is used when A4723 or A4725 applies because the billing team hasn’t reviewed the patient’s current prescription. Prescription volumes change with clinical status, and billing codes need to change with them.

A quarterly audit of active peritoneal dialysis patients, comparing prescribed volume to the code currently in the billing system, catches most of these before they become denials. HIPAA-compliant record management practices ensure prescription updates are captured in the patient file and accessible to billing staff without delay.

Missing or incomplete Standard Written Order

Since January 1, 2023, CMS requires a Standard Written Order (SWO) rather than a Certificate of Medical Necessity (CMN) or DME Information Form (DIF) for DMEPOS claims — dialysate solution was never among the categories that required a CMN in the first place, but an incomplete or missing SWO still guarantees a denial.

Billing teams should confirm the SWO is on file and specifies the peritoneal dialysis modality and prescribed volume before each claim cycle, particularly for new patients or patients whose clinical status has changed.

Keeping SWO completion as a structured step in the patient onboarding workflow, rather than a post-hoc retrieval task, is the reliable fix. Structured digital medical forms built around the SWO requirement reduce missing-document denials significantly.

Incorrect units billed

A4724 is billed per day, not per bag or per delivery. Billing a monthly supply as a single unit, or billing by delivery event rather than service day, produces incorrect unit counts.

The billing unit should reflect the number of days in the service period for which the prescribed volume was delivered. Delivery records and the physician’s treatment plan are the two documents that anchor unit count verification. HIPAA-compliant record access for billing staff makes cross-referencing delivery records against billing claims straightforward.

Billing the DME MAC directly instead of the ESRD facility

Because A4724 sits on CMS’s ESRD PPS Consolidated Billing list, a supplier that submits a standard claim straight to the DME MAC for a peritoneal dialysis patient’s dialysate solution will typically be denied. Medicare expects that cost to be bundled into the ESRD facility’s per-treatment payment, with the supplier billing the facility under arrangement instead.

This mistake often comes from applying general DMEPOS billing habits, built around separately payable equipment, to a supply that’s already consolidated under ESRD PPS. Before onboarding a new home peritoneal dialysis patient, confirm whether the supplier has a billing arrangement with the patient’s ESRD facility.

Reserve DME MAC submission, with the AY modifier, for the narrow case where the supply is unrelated to ESRD treatment. Using practice management software that flags which supply codes are consolidated under ESRD PPS helps catch this before claims go out the wrong door.

Conclusion

HCPCS Code A4724 is straightforward on paper and costly in practice when the volume threshold, documentation, or supplier eligibility isn’t verified before submission. The difference between A4723, A4724, and A4725 is a matter of cc per day, and that distinction drives which code is billable and which will deny.

Pabau’s claims management software helps dialysis and nephrology billing teams build structured verification steps directly into the billing workflow, linking supply code selection to the active prescription and flagging missing documentation before claims go out. To see how Pabau handles DMEPOS billing workflows, book a demo.

Continue your research

Need another dialysis-related supply code? Our billing guide for A4672 covers the sterile drainage extension line billed alongside dialysate solution in home peritoneal dialysis.

Managing the non-billing side of ESRD care? Our renal diet meal plan template gives dialysis patients a structured 7-day meal plan.

Looking for HCPCS references for other DME supply categories? Our billing guide for A4651 covers the calibrated microcapillary tube, another commonly billed supply code.

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