HCPCS code P9045 – Albumin 5% infusion, 250 ml billing guide

Key takeaways

HCPCS code P9045 covers albumin (human) 5%, billed one unit for every 250 ml infused.

A 500 ml bottle bills as two units, while 50 ml bottles of 5% albumin go on P9041.

Hospital outpatient departments are paid separately under OPPS status indicator K, at $53.079 per unit for October to December 2026.

The infusion itself is billed with a CPT administration code, such as 96365, on the same claim.

The chart has to show the indication, the volume given and the bottle sizes, because they drive coverage and units.

HCPCS code P9045 bills one unit per 250 ml of 5% albumin

HCPCS code P9045 reports albumin (human) 5% in units of 250 ml. The CMS long descriptor reads infusion, albumin (human), 5%, 250 ml, and the short descriptor is “Albumin (human), 5%, 250 ml.”

The CMS HCPCS file lists January 1, 2002 as the date the code was added. P9045 is still active in the October 2026 file. That file gives it Medicare coverage code C, carrier judgment, so your Medicare Administrative Contractor (MAC) decides coverage.

A 5% solution holds 5 g of albumin per 100 ml, so each P9045 unit carries 12.5 g. Branded 5% products such as Flexbumin 5%, Plasbumin-5 and Albutein 5% all map to P9045 or P9041. The container volume decides which one, never the manufacturer.

When 5% albumin is medically necessary

Payers accept P9045 when the record ties the infusion to a labeled indication. The FDA prescribing information for Flexbumin 5%, for example, lists these uses:

• Hypovolemia: restoring circulating volume when a colloid is appropriate.
• Hypoalbuminemia: from inadequate production, excessive catabolism, loss from the body, or redistribution, such as after major injury, infection or pancreatitis.
• Burns: after the first 24 hours, alongside crystalloid therapy, to treat oncotic deficits and replace protein loss.
• Cardiopulmonary bypass surgery: as part of the fluid management for the procedure.

Other 5% labels, such as Albutein 5%, also list therapeutic plasma exchange, where albumin replaces the plasma removed. The labels state that albumin is not indicated as an intravenous nutrient. A claim that documents nutritional support alone is unlikely to survive review.

CMS has no national coverage determination specific to albumin. With coverage code C, the MAC applies its own reasonable and necessary test. Check your MAC’s policy articles before billing an indication that sits outside the product label.

P9045 vs. the other albumin and plasma protein codes

CMS splits albumin by concentration and container volume, and it codes plasma protein fraction separately. P9045 and P9047 carry the same 12.5 g of albumin per unit. One delivers it in 250 ml of 5% solution, the other in 50 ml of 25% solution.

Descriptors come from the October 2026 CMS HCPCS file, and payment from the OPPS Addendum B for the same quarter. Pick the concentration first, then the container. A 5% product in 250 ml or 500 ml bottles goes on P9045, and 50 ml bottles of 5% go on P9041.

Plasma protein fraction is a different product, even at the same 5% strength. OPPS also treats it differently. It carries status R as a blood product, while the four albumin codes carry status K and are paid like drugs.

Count P9045 units from the volume infused

Divide the total milliliters of 5% albumin given by 250, and that is the unit count. Read the volume from the administration record, then check it against the bottles dispensed.

• One 250 ml bottle bills as one unit of P9045.
• One 500 ml bottle bills as two units of P9045.
• Two 250 ml bottles plus two 50 ml bottles bill as two units of P9045 and two units of P9041, on separate lines.
• A plasma exchange that uses 3,000 ml of 5% albumin as replacement fluid bills as 12 units of P9045.

Plasma exchange is where high unit counts stop claims. Before you submit a large line, check P9045 against the medically unlikely edit (MUE) table CMS publishes for outpatient hospital services. Keep the exchange volume in the procedure note, so an appeal has the figures it needs.

Diagnosis codes that support a P9045 claim

The ICD-10-CM code on the claim has to explain why the patient needed volume or albumin replacement. The codes below match the labeled indications. Each one still needs the treating clinician’s documentation behind it.

ICD-10-CM changes every October, so confirm each code in the CDC ICD-10-CM browser tool before you submit. A diagnosis outside the product label needs a fuller clinical note explaining why albumin was chosen.

Pair P9045 with the CPT code for the infusion

P9045 codes the albumin only. Giving it is a separate CPT line, usually 96365 for the first hour of an IV infusion. Leaving that line off loses the administration payment.

• CPT 96365: intravenous infusion for therapy, prophylaxis or diagnosis, initial, up to 1 hour.
• CPT 96366: each additional hour of the same infusion, reported as an add-on to 96365.
• CPT 36514: therapeutic apheresis for plasma pheresis. When 5% albumin is the replacement fluid, bill the P9045 units on the same claim.

When albumin is given inside a surgical case, such as cardiopulmonary bypass, the surgery and anesthesia codes cover the service. Only the product units go on the P9045 line.

How Medicare pays for P9045

Medicare pays P9045 three different ways, depending on where the albumin is given. In every case the payment covers the product, and the administration is paid on its own line.

In the outpatient department, the October 2026 Addendum B sets $53.079 per unit, with a minimum unadjusted copayment of $10.62. P9045 is not packaged into the infusion APC, so each unit pays.

For a physician office, the CMS Part B payment limit file lists the same $53.079 per 250 ml for October 1 to December 31, 2026. The file prices P9045 in its blood column at 95% of average wholesale price, rather than at average sales price plus 6%.

Both rates change every quarter, so treat these figures as a reference point and recheck them each January, April, July and October. At the October 2026 rate, the 12-unit plasma exchange above pays $636.95 before coinsurance.

OPPS pays P9045 as a drug rather than as a status R blood product. Hospitals therefore generally report it under revenue code 0636, drugs requiring detailed coding, rather than the 038X blood codes. Confirm the pairing your MAC expects.

Modifiers on a P9045 line

No modifier is specific to P9045, and most lines carry none. Three situations can add one:

• JW or JZ: JW reports a discarded amount from a single-dose container, and JZ attests that none was discarded. CMS guidance on these modifiers does not name the albumin codes, so ask your MAC whether it expects either on P9045.
• GA: a valid Advance Beneficiary Notice (ABN) is on file because the infusion was expected to be denied as not reasonable and necessary.
• GZ: the same expected denial, with no ABN issued.

EA, EB and EC do not belong on an albumin line. They identify erythropoiesis-stimulating agents given for anemia, and they say nothing about a blood product’s attributes.

What an auditor expects to find in the chart

Each element of a P9045 claim needs a matching entry in the record. An auditor checks that the order, the administration record and the claim line agree on product and volume.

• Order: albumin (human) 5%, the volume, the rate and the indication, signed and dated.
• Evidence for the indication: vital signs and volume status for hypovolemia, a serum albumin value for hypoalbuminemia, or the burn TBSA.
• Procedure note: for plasma exchange or bypass, the replacement or priming volume and the share that was 5% albumin.
• Administration record: start and stop times, volume infused, lot number and the product NDC.
• Bottle count by size: enough detail to split units between P9045 and P9041.
• ABN: where coverage was in doubt and the patient was notified before the infusion.

Volume is the field most likely to disagree across records. Reconcile the pharmacy dispense, the administration record and the charge line before the claim leaves, not after the remittance comes back.

Prior authorization and payer rules

Original Medicare does not require prior authorization for albumin. Medicare Advantage plans, Medicaid programs and commercial payers set their own rules, so check each plan at eligibility verification.

• Medicare Advantage: some plans review outpatient albumin infusions before scheduling. Check the plan’s drug or infusion policy.
• Medicaid: most state programs require the NDC on physician-administered drug lines, alongside the HCPCS code and units.
• Commercial payers: many also require the NDC, and some limit albumin to hospital settings or labeled indications.

Record any authorization number on the claim. Emergent infusions for shock or bypass are rarely delayed for authorization, so document the urgency in the clinical note.

Common P9045 denials and how to prevent them

Most P9045 denials trace back to concentration, volume or setting. The table pairs each pattern with the check that stops it. For the remittance codes behind them, see our guide to medical billing denial codes.

Track denials by code rather than in aggregate. A repeated pattern on P9045 usually points to one broken handoff, and denial management works best when it fixes that handoff first.

How Pabau keeps P9045 claims consistent with the chart

Albumin claims fail when the volume lives in three places. The dispensing log, the infusion note and the charge line are often kept apart, and someone has to reconcile them by hand.

Pabau, the practice management and EHR platform we build, keeps the order, the treatment note and the invoice on one patient record. Charge entry works from what the clinician documented, so nobody rekeys a volume off a printout.

For US practices, Pabau’s claims management software builds the claim from data already on the record and submits it through Claim.MD. Your team still chooses the code and the units. Pabau carries those choices onto the claim and tracks it until payment posts.

Keep albumin claims matched to the chart

Pabau keeps the order, treatment note and invoice on one patient record, then submits US claims through Claim.MD. Your billing team spends less time rekeying volumes and reworking denials.

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Conclusion

P9045 turns on two facts from the chart: the concentration and the volume. Confirm the product is 5%, split the bottles by size, and divide by 250.

The trade-off sits in plasma exchange. Those cases produce the largest unit counts, and a 12-unit line that fails an edit costs more staff time than the bedside check. Reconcile the volume while the infusion record is still open.

Book a demo to see how Pabau keeps clinical records and US claim submission on one patient record.

Continue your research

Want to see how a claim reaches the payer? Medical claims clearinghouse explains payer routing, edit checks and how rejected claims come back.

Need a system for repeat denials? Denial management in healthcare covers how to track, appeal and prevent denials by reason code.

Checking what the payer actually paid? Electronic remittance advice shows how to read 835 files and spot contractual adjustments.

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