HCPCS Code A4755: Blood tubing, arterial and venous combined

Key takeaways

HCPCS Code A4755 is the supply code for blood tubing, arterial and venous combined, for hemodialysis, each.

A4755 sits on Medicare’s ESRD PPS consolidated billing list, so the dialysis facility carries it inside its bundled payment.

Home hemodialysis follows the same rule, because Method II billing by DME suppliers ended on January 1, 2011.

A4750 covers one arterial or venous line, so recording two units of it for a combined set is a coding error.

Practice management software like Pabau helps billing teams keep supply records and claim status in one place.

What HCPCS Code A4755 covers

HCPCS Code A4755 is the Level II supply code for blood tubing, arterial and venous combined, for hemodialysis, each. One unit is one combined tubing set. That set holds the arterial line carrying blood to the dialyzer and the venous line returning it to the patient.

The code rarely produces a payment of its own. A4755 appears on Medicare’s ESRD consolidated billing list, so the dialysis facility is paid for the tubing inside its per-treatment bundle. Anyone new to medical billing for dialysis should start with that distinction.

This reference covers the official descriptor, the consolidated billing rules, how payment reaches the facility in 2026, documentation, modifiers, and how A4755 differs from A4750.

A4755 at a glance

A4755 is a Level II supply code maintained by the Centers for Medicare and Medicaid Services (CMS). It belongs to the A-series, which covers medical and surgical supplies, durable medical equipment (DME), and related items billed outside the physician fee schedule.

Blood tubing in a hemodialysis session

A hemodialysis session needs two tubing lines. The arterial line carries blood from the patient to the dialyzer, and the venous line returns the filtered blood. A4755 covers a set in which both lines are packaged and reported together as a single unit.

Combined sets are the standard configuration at most in-center facilities. Each set is single-use and replaced for the next treatment. A patient on three sessions a week goes through three combined sets a week, recorded under A4755 or A4750 depending on the configuration.

• Arterial tubing: draws blood from the patient’s access point, whether that is a fistula, a graft, or a catheter
• Venous tubing: returns filtered blood from the dialyzer to the patient’s bloodstream
• Combined set (A4755): the arterial and venous segments packaged together as one unit
• Single tube (A4750): either the arterial or the venous segment alone, never both

The one decision that matters is whether the session used a combined set or two separate tubes. Recording two units of A4750 for a combined set misstates the supply, and so does recording A4755 when only one line was used.

A4755 vs A4750: key differences for accurate billing

Confusing A4755 with A4750 is the most common error in dialysis supply coding. Both describe hemodialysis blood tubing, and both are valid codes, so the wrong one will not always bounce back. It still leaves the supply record wrong and the facility exposed at audit.

The supply record settles it. Note in the treatment record which configuration the session used, and the code follows from the record rather than from habit.

Related HCPCS codes for dialysis supplies

A4755 sits in a family of A-series dialysis supply codes, and each one covers a distinct item. The AAPC HCPCS lookup tool is useful for checking a full descriptor, including codes outside this range such as P9010 for blood products.

Note that A4760 and A4765 are peritoneal dialysis codes, so neither belongs on a hemodialysis supply line. Nephrology billing teams also handle codes well outside the A-series. Patients who move on to transplant bring immunosuppressant codes such as J7525 and J7502 into the same claim workflow.

Medicare coverage and ESRD consolidated billing

Under the ESRD Prospective Payment System (ESRD PPS), the dialysis facility receives one bundled payment per treatment. That payment is designed to cover the supplies a hemodialysis session needs, blood tubing included. A4755 is therefore not separately payable to Medicare.

A4755 also appears on the CMS ESRD PPS consolidated billing list, which names the supply codes Medicare will not pay to a DME supplier. No second billing path exists. If the tubing was used for dialysis, the bundled payment to the facility has already covered it.

• In-center hemodialysis, Medicare: bundled into the facility’s per-treatment payment
• Home hemodialysis, Medicare: also bundled, since Method II supplier billing ended on January 1, 2011
• Medicaid: coverage and bundling vary by state, so confirm with the state program
• Commercial payers: may pay A4755 on its own line, so read each contract

Set side by side, the payer picture is easier to hold on to.

Keep Medicare’s rules apart from everyone else’s. Applying ESRD bundling to a commercial plan can leave a payable supply unbilled. Assuming separate payment under Medicare produces a line that will never pay. Medical billing compliance work on supply codes runs payer by payer.

How A4755 gets paid in 2026

There is no separate 2026 Medicare amount to look up for A4755. Payment reaches the facility through the ESRD PPS base rate, which CMS updates annually and adjusts for local wage levels. Separate payment for the tubing only comes from a payer outside that system.

The CMS DMEPOS fee schedule does not offer an alternative route. Because A4755 is on the consolidated billing list, a DME supplier cannot be paid for it, even when the patient dialyzes at home.

Quote a figure only with its year and its source attached. For this code that source is the annual CMS rule and the consolidated billing files, not a third-party lookup tool.

How to document and bill A4755

Documentation is what makes the code defensible, whether or not it draws a payment of its own. Clean claim work on dialysis supplies comes down to the treatment record, the supply log, and the code agreeing with one another.

1. Confirm the payer first. Under Medicare, consolidated billing settles it, so separate billing is only a question for Medicaid and commercial plans.
2. Document the supply. Record that the session used a combined arterial and venous set rather than two single lines.
3. Report the correct units. One combined set is one unit of A4755, and a second unit needs a second set in the record.
4. Check modifier rules. Where a payer does accept the code on its own line, that payer’s guidance decides which modifiers, if any, belong on it.
5. Attach what the payer asks for. Treatment logs and supply records are the usual evidence behind a dialysis supply claim.

Denials on supply codes cluster by payer rather than by claim. Reading remittance advice by code shows which payer keeps rejecting A4755, and the reason is usually a coverage assumption rather than a keying slip.

Applicable modifiers for A4755

Most A4755 lines never reach a modifier question. Consolidated billing means the code is not separately payable to Medicare, so there is no separate line for a modifier to qualify. Modifiers only come into play where a payer accepts the code on its own.

Check the payer’s own guidance before appending any of them. No modifier turns a bundled supply into a separately payable one.

Why the payer matters more than the jurisdiction

Medicare Administrative Contractors (MACs) process claims by region, and local coverage articles do differ between them. For A4755, the jurisdiction rarely changes the answer. The ESRD PPS base rate is national, adjusted for area wages, and consolidated billing applies everywhere. What changes the answer is the payer, since state Medicaid programs and commercial plans write their own supply rules.

Dialysis supply billing that stays clean

Dialysis billing runs on volume. Recurring sessions, firm bundling rules, and payer-by-payer variation are hard to hold together by hand. Tracking denial management by HCPCS code shows which supply codes and which payers produce the rejections.

• Flag Medicare claims automatically: configure the billing system so a separately billed A4755 line cannot leave on an ESRD PPS claim
• Match supply records to treatment logs: every combined set recorded should trace back to a documented hemodialysis session
• Audit A4750 and A4755 together each quarter: if the facility stocks only combined sets, A4750 should not be turning up in the supply record
• Review commercial policies once a year: payers revise dialysis supply coverage quietly, so put the review in the calendar
• Track denial reasons by code: a handful of reasons explain most supply denials, and each one has a different fix

The same pressure shows up wherever treatment is recurring and supply-heavy. Teams weighing up infusion center software or a metabolic health EMR ask the same question about which supplies sit inside a bundled payment.

How Pabau helps dialysis billing teams manage supply codes

Most dialysis billing teams work across two systems. Supply use is written into the treatment record, the claim is built somewhere else, and somebody reconciles the two by hand every week. That is where a combined set turns into two units of A4750.

Practice management software like Pabau keeps the treatment record and the claim in one place. Supplies logged against a session stay attached to that patient’s chart. The code on the claim and the set that was used come from the same source. Pabau’s claims management software then tracks each claim by payer, from submission through to the remittance.

For US practices, claims leave through the Claim.MD integration, our clearinghouse connection. It submits what your team has already coded and reports back what the payer did with it. Your coders still decide the code, and nobody spends a morning hunting for the supply record behind a rejected line.

Keep dialysis supply codes tied to the record

Pabau keeps supply use, patient records, and claim status in one system. Dialysis billing teams can see what was used, what was submitted, and what came back.

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Conclusion

A4755 is an easy code to describe and an easy one to bill wrongly. Under Medicare the answer is already settled. The bundled payment to the facility covers the tubing, and no DME supplier route survives.

So the work sits elsewhere. Get the configuration right between A4755 and A4750. Keep the supply record lined up with the treatment log, and read every non-Medicare contract on its own terms. Practices that do those three things rarely have to rebill a supply line.

If denials keep landing on dialysis supply lines, the denial codes reference is the next stop. Book a demo to see how Pabau ties supply records to claim submission for nephrology billing teams.

Continue your research

Billing blood products alongside dialysis? P9010 covers whole blood for transfusion and follows its own payment rules.

Coding for transplant patients on immunosuppressants? J7525 sets out how parenteral tacrolimus is reported and documented.

Need the contrast with durable equipment? K0821 shows how a purchase and rental code differs from a single-use supply.

Patients carrying balances on dialysis-related care? Patient payment plans explains how to structure and track them without chasing.

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