HCPCS code B5100 – Hepatic parenteral nutrition premix

Key takeaways

HCPCS code B5100 is the hepatic amino acid premix (HepatAmine) for home parenteral nutrition, not a standard or general-purpose formula.

B5000 is the renal premix and B5200 the stress premix, while standard premixes bill under B4189 to B4199 by grams of protein per day.

One unit of B5100 equals one gram of amino acid, so the gram count on the compounding record drives the units on every claim line.

CMS retired the CMS-10126 DME Information Form for dates of service from January 1, 2023, and claims sent with it attached are rejected.

Every B5100 line needs a KX, GA, GY, or GZ modifier under policy article A58836, or the DME MAC rejects it as missing information.

HCPCS code B5100: Definition and code details

HCPCS code B5100 describes a premixed parenteral nutrition solution built on a hepatic amino acid pattern, the HepatAmine formula named in its descriptor. It is used for home parenteral nutrition patients whose liver disease calls for a modified amino acid profile. Each unit is one gram of amino acid.

The code sits in the B-series of HCPCS Level II, which covers enteral and parenteral therapy. Medicare pays it under the Prosthetic Device benefit, and claims go to the DME MAC rather than the Part B MAC.

Official descriptor and key reference data

The table below summarizes the key reference fields for B5100. Each one comes from the CMS October 2026 HCPCS file or from policy article A58836.

What B5100 covers and what it excludes

B5100 applies when the treating practitioner orders a premixed hepatic formula for a patient on home parenteral nutrition. The liver disease explains the formula choice. It does not, on its own, make the patient eligible for parenteral nutrition.

Eligibility comes from the gut. LCD L38953 requires a permanent condition that impairs absorption in the small intestine, or a motility disorder that blocks transport through the GI tract. A patient with cirrhosis and a working gut does not qualify, whatever the formula.

These scenarios use different codes:

• Renal premix (Aminosyn-RF, NephrAmine, RenAmin): Bill B5000, not B5100.
• Stress premix with branched-chain amino acids (FreAmine HBC): Bill B5200, not B5100.
• Standard premix with no disease-specific pattern: Bill B4189, B4193, B4197, or B4199, chosen by grams of protein per day.
• Home-mix components: Bill carbohydrates (B4164, B4180), amino acids (B4168 to B4178), and additives (B4216) separately, with no premix code.
• Lipids: Bill B4185 or B4187 per 10 grams, as a separate line alongside B5100.
• Enteral nutrition through a feeding tube: Use the enteral B-codes (B4034 to B4162), not B5100.
• A Part A covered skilled nursing facility (SNF) stay: The SNF bills the stay, and no Part B payment applies.

When the formula changes, the code changes with it. If a hepatic patient moves to a standard premix, bill B4189 to B4199 from the date of the new order. Billing B5100 for a formula the pharmacy no longer compounds creates an overpayment that an audit will find.

B5100 vs neighboring parenteral nutrition HCPCS codes

B5100 belongs to a trio of disease-specific premixes: B5000 renal, B5100 hepatic, and B5200 stress. All three bill per gram of amino acid, which sets them apart from the standard premixes billed per day.

Under the premix rule in policy article A58836, the carbohydrates, amino acids, and additives in the bag are not billed separately. Lipids are the one exception.

A worked example: From grams to units

Say the treating practitioner orders a hepatic premix that delivers 60 grams of amino acid a day. Each day of therapy bills as 60 units of B5100.

Add 500 mL of 20% lipids and the patient receives 100 grams of lipids, or 10 units of B4185. Never fold the lipid grams into the B5100 count.

Compare that with a standard premix. Sixty grams of protein a day bills as one unit of B4193, however many bags deliver it. Side by side, the two unit counts land far apart.

Documentation requirements for parenteral nutrition claims

The paperwork for B5100 changed in 2023. CMS stopped requiring the CMS-10126 DME Information Form, often called the parenteral nutrition CMN, for dates of service on or after January 1, 2023. Claims sent with a CMN or DIF attached are now rejected and returned.

The medical record does that job now. Keep these on file and ready for a records request:

• Standard Written Order: The beneficiary’s name or MBI, the order date, the item, the quantity, and the treating practitioner’s name, NPI, and signature.
• Medical record evidence: Notes that show the GI condition, the test of permanence, and the reason for the hepatic formula.
• Compounding records: The formula record showing grams of amino acid per day, which supports the units on the claim.
• Proof of delivery: A delivery record for each shipment, kept under standard documentation article A55426.

Keep the full set together on the patient record. A DME MAC records request can then be answered from one place, not pieced together from the pharmacy and the prescriber.

Medicare coverage and payer requirements for B5100

Medicare covers home parenteral nutrition under the Prosthetic Device benefit, so claims route to the DME MAC for the patient’s state. Two contractors run the four jurisdictions: CGS Administrators covers B and C, and Noridian Healthcare Solutions covers A and D.

Coverage is set by LCD L38953 (Parenteral Nutrition) and its policy article A58836. The core requirements are:

• A qualifying GI condition: A condition of the small intestine or its exocrine glands that significantly impairs absorption. A motility disorder that impairs transport through the GI tract also qualifies.
• The test of permanence: The treating practitioner’s judgment, recorded in the chart, that the impairment will be of long and indefinite duration.
• Ongoing monitoring: The supplier must keep checking that the coverage criteria are still met.

L38953 lists no covered ICD-10-CM codes, so no diagnosis code guarantees payment on its own. The medical record has to show the GI mechanism.

The billing supplier must be an enrolled, accredited DMEPOS supplier. A practitioner who only writes the order cannot bill B5100. IV therapy practices running home infusion programs should confirm their accreditation before the first claim.

Nursing visits to give parenteral nutrition at home are not a DME MAC benefit. For coding questions about a specific product, contact the Pricing, Data Analysis and Coding (PDAC) contractor.

Also check the CMS Required Face-to-Face Encounter and Written Order Prior to Delivery List before the first claim date, because CMS updates it periodically.

ICD-10-CM codes that commonly appear on B5100 claims

A B5100 claim usually carries two kinds of diagnosis. One supports the hepatic formula, and the other supports parenteral nutrition itself.

Treat this list as typical, not as a covered list. The chart still has to document the absorption or motility failure and the test of permanence.

How to correctly bill this code: Units, modifiers, and claim fields

Billing B5100 correctly means matching units, modifiers, and claim fields to policy article A58836. Errors in these fields usually lead to a rejection that needs a corrected claim.

Check the CMS DMEPOS fee schedule for the current per-gram allowable in your state. CMS updates it every January and again each quarter, so never reuse a prior-year figure.

Lipids (B4185, B4187) go on the same claim as separate lines when the patient receives both. Our HCPCS code library lists the other B-series codes with their descriptors.

Common B5100 claim denial reasons

These are the common causes of B5100 denials, each with its fix. Fixing them before submission is faster than working a denial queue afterward.

• Wrong formula code: B5100 is billed for a standard, renal, or stress formula. Fix: Match the code to the formula on the compounding record for every date of service.
• Units billed per day: One unit of B5100 is billed for a day’s bag. Fix: Bill one unit per gram of amino acid.
• Unbundled premix components: Amino acids, dextrose, or additives are billed alongside B5100. Fix: Bill the premix code alone, plus lipids where the patient receives them.
• No payment modifier: The line carries no KX, GA, GY, or GZ. Fix: Add KX only where every LCD criterion is documented, and the correct alternative otherwise.
• Eligibility not documented: The chart shows liver disease but no GI absorption or motility impairment. Fix: Document the GI condition and the test of permanence before the first claim.
• Retired form attached: A CMN or DIF is sent with a claim dated on or after January 1, 2023. Fix: Drop the attachment and keep the Standard Written Order on file instead.
• Part A stay billed to the DME MAC: The patient was in a Part A covered SNF stay. Fix: Let the SNF bill the stay, because Part B does not pay.
• Non-accredited supplier: The billing entity lacks current DMEPOS accreditation. Fix: Confirm accreditation and enrollment before the first claim.

A pre-submission check that compares the compounding record, the order, and the claim line catches these mismatches before the DME MAC does.

Related HCPCS codes

• B5000: Renal amino acid premix, billed per gram of amino acid.
• B5200: Stress premix with branched-chain amino acids, billed per gram of amino acid.
• B4189, B4193, B4197, B4199: Standard premixes, billed per day and tiered by grams of protein.
• B4185: Parenteral nutrition lipids, not otherwise specified, per 10 grams.
• B4187: Omegaven lipids, per 10 grams.
• B4216: Home-mix additives, per day, which are not billable alongside B5100.
• E0776: IV pole, billed with the BA modifier when used with parenteral nutrition.
• B9999: Parenteral supplies not otherwise classified, including solutions under 10 grams of protein a day.

How Pabau keeps B5100 claims and documentation aligned

B5100 claims fail on details that live in different places. The formula sits in the pharmacy record, the gram count drives the units, and the practitioner’s notes carry eligibility. Many billing teams still track all three across spreadsheets and email.

Pabau keeps the order, clinical notes, and forms on one patient record. Its claims management software tracks each claim and its status, so a rejected line is easy to trace back to its documentation.

The result is a billing team that checks units and modifiers against the chart before a claim goes out. Fewer claims come back, and records requests take less time to answer.

Keep parenteral nutrition claims and records aligned

Pabau keeps clinical notes, digital forms, and claim tracking on one patient record. Your team can check each B5100 claim against its documentation before it goes out.

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Conclusion

Treat the compounding record as the source of truth for every B5100 claim. The formula on it decides the code, and the gram count on it decides the units.

The trade-off is extra checking at the start of each episode. Document the GI impairment alongside the liver disease, and recode from the day the formula changes. That upfront work costs less than a corrected claim or an overpayment found at audit.

Book a demo to see how Pabau keeps clinical records and claim tracking together for your billing team.

Continue your research

Want fewer claims coming back from payers? Pabau’s claims management software tracks each claim, its status, and the denials your team needs to work.

Billing a renal patient instead? HCPCS code B5000 covers the renal amino acid premix and how its per-gram units are counted.

Need the supply kit code too? HCPCS code B4220 explains the parenteral nutrition supply kit that often ships alongside the premix.

New to DME MAC claims? Medicare billing for practices walks through the claiming channels and compliance rules behind every Medicare claim.

Working a denial right now? Denial codes in medical billing lists the top 20 CARC codes and the fix for each one.

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