HCPCS code B4199 – Premix parenteral nutrition, over 100 grams of protein

Key takeaways

B4199 is a premix parenteral nutrition code. It applies when the ordered protein dose is over 100 grams per day.

It is the top tier of four per-day premix codes, above B4189, B4193, and B4197. Orders under 10 grams a day go to B9999.

One unit is one day’s supply, whatever the fluid volume or the number of bags.

The January 2026 Medicare PEN fee schedule lists B4199 at $472.87 per day. That is $59.04 a day more than B4197.

Medicare claims rest on a standard written order, LCD L38953 records, proof of delivery, and the KX modifier. CMS retired the DIF in 2023.

Pabau, our practice software, keeps the order, the clinical notes, and the claim in one patient record. Billers can check the gram dose before submitting.

HCPCS code B4199: Definition and official descriptor

HCPCS code B4199 is the Level II billing code for premixed parenteral nutrition when the ordered protein dose is over 100 grams per day. The pharmacy compounds the solution from amino acids and carbohydrates, with electrolytes, trace elements, and vitamins included. It sits in the CMS HCPCS Level II B-series and is billed to the DME MAC.

Two words in the descriptor shape the billing. “Premix” means the solution arrives fully compounded, so its components never appear as separate claim lines. “Including preparation” puts the compounding work inside the B4199 rate.

B4199 is not a miscellaneous or not otherwise classified code. It has a fixed descriptor and a national fee schedule amount. The not otherwise classified code in this family is B9999, which Policy Article A58836 uses for solutions under 10 grams of protein a day.

Where B4199 sits in the premix protein tiers

The four per-day premix codes split by the grams of protein ordered per day. B4199 has no upper limit, so every premix order above 100 grams lands here. The table maps the tiers and the neighboring codes billers confuse with them, using the January 2026 PEN fee schedule.

The boundaries are exact. A 100 gram order belongs to B4197, so billing B4199 at that dose overbills by $59.04 a day. A 101 gram order belongs to B4199, and billing B4193 or another lower tier leaves money unclaimed.

B4216 never belongs on a B4199 claim. It codes the additives in a home-mix regimen, and premix solutions already include them. Renal, hepatic, and stress formulas have their own premix codes, B5000, B5100, and B5200, billed per gram of amino acid.

What B4199 covers and what it does not

Policy Article A58836 sets the bundling rule for every premix code. Once B4199 is billed, the components inside the solution cannot be billed again on separate lines.

• Bundled into B4199: Amino acids, carbohydrates, and the additives, meaning vitamins, trace elements, heparin, and electrolytes. Preparation is bundled too.
• Billed separately: Lipid emulsion, under B4185 or B4187, at one unit per 10 grams of lipids. The infusion pump and the daily supply allowance have their own codes.
• Outside the DME MAC claim: Nursing visits and infusion administration, which this benefit does not pay for.

A separate line for B4216, vitamins, or electrolytes next to B4199 is unbundling. Lipids are the one nutrient exception, so 500 ml of 20% lipids bills as 10 units of B4185 or B4187.

Protein math: When an order over 100 grams needs extra documentation

LCD L38953 requires extra documentation for any protein order outside 0.8 to 2.0 grams per kilogram per day. Because B4199 starts above 100 grams, the patient’s weight decides which side of that line an order falls on.

At the 2.0 gram ceiling, an order just over 100 grams stays in range only for a patient above 50 kilograms. A lighter patient on a B4199 dose needs the clinical reason written into the record.

Read the other way, the same limits give every B4199 order a weight window. A patient inside it needs no extra justification, and a patient outside it needs a written reason.

Calories follow the same pattern. The LCD treats 20 to 35 calories per kilogram per day as reasonable and necessary. Intake outside that range needs documented medical necessity for the individual patient.

Medicare coverage criteria for B4199

Medicare covers parenteral nutrition under the prosthetic device benefit when the patient meets LCD L38953. Enteral nutrition is usually tried first, so the record has to show why it will not work.

• Qualifying condition: A disease of the small intestine or exocrine glands that significantly impairs absorption, or a motility disorder of the stomach or intestine.
• Enteral nutrition ruled out: The practitioner documents that enteral feeding was considered and ruled out, tried without success, or makes the GI dysfunction worse.
• Permanence: The practitioner judges the impairment to be of long and indefinite duration, which is the test in Policy Article A58836.
• 30-day evaluation: The treating practitioner evaluates the patient within 30 days before therapy starts, or records why not and how the patient was monitored.
• KX modifier: Appended only when every criterion is met and the evidence sits in the supplier’s files.

Two contractors process B4199 claims across the four DME MAC jurisdictions. Noridian runs Jurisdictions A and D, and CGS Administrators runs B and C. Route each claim by the state where the beneficiary permanently resides.

Part B pays nothing for parenteral nutrition during a Part A covered stay. In that case the skilled nursing facility bills the solution through its own Part A claim.

Prior authorization for B4199

Neither LCD L38953 nor Policy Article A58836 sets a prior authorization step for Medicare parenteral nutrition. The supplier attests to coverage on the claim with KX, and reviewers test that attestation against the records later.

Medicaid programs and commercial plans set their own rules, and some require prior authorization for B4199. When a supplier expects Medicare to deny a line as not reasonable and necessary, a signed Advance Beneficiary Notice lets it bill the patient instead.

Documentation requirements for B4199 claims

CMS no longer uses a form to certify parenteral nutrition. The DME information form, CMS-10126, was retired for dates of service on or after January 1, 2023, as CGS confirms. Claims sent with one attached are rejected, and four records carry the claim instead.

1. Standard written order (SWO): On file before the claim goes out, naming the formula and the ordered protein in grams per day. Without the gram dose, the claim file cannot show that B4199 applies rather than B4197.
2. Treating practitioner evaluation: Recorded within the 30 days before therapy starts, showing the impairment and why enteral nutrition will not work.
3. Dose justification: A recorded reason whenever the order falls outside 0.8 to 2.0 grams of protein or 20 to 35 calories per kilogram per day.
4. Proof of delivery: A delivery record showing the date, the item, and the quantity for every billed date of service.

Records that tie the dose to measured need make the file stronger. A dietitian assessment of weight, calorie needs, and protein needs does that directly, and progress notes support continued therapy.

ICD-10-CM diagnosis codes that can support B4199

LCD L38953 and Policy Article A58836 publish no list of covered diagnosis codes. Medical necessity rests on the record, so the codes below are examples rather than a list that guarantees payment. Check each code’s full descriptor and coding notes in the ICD-10-CM code library before you pair it with B4199.

K90.821 and K90.83 carry an Excludes1 note for malabsorption after GI surgery, which is coded to K91.2 instead. The notes should still name the condition, describe how it impairs absorption, and explain why enteral nutrition failed.

Modifiers for B4199

Policy Article A58836 requires a coverage modifier on every parenteral nutrition line. A B4199 line without KX, GA, GZ, or GY is rejected as missing information.

Units above the treating practitioner’s order get separate treatment. Since January 1, 2023, suppliers calculate units from the order, and excess units must not carry KX. Bill those units with GA or GZ instead.

Fee schedule and unit calculation for B4199

CMS prices B4199 per day on the Parenteral and Enteral Nutrition (PEN) fee schedule. The January 2026 file lists $472.87 per unit, the same amount in every state. Check the current quarter’s file before you bill.

Medicare pays 80% of the allowed amount after the Part B deductible. The patient or a secondary payer covers the 20% coinsurance.

Units follow the calendar. A 30 day supply at 120 grams of protein a day is 30 units of B4199, whatever the bag count. At the January 2026 rate, that month is allowed at $14,186.10 before coinsurance.

Claim submission steps for B4199

1. Confirm the standard written order specifies a protein dose above 100 grams per day.
2. Check the patient’s weight, and document the reason if the dose exceeds 2.0 grams per kilogram.
3. Confirm the SWO and the 30 day practitioner evaluation are on file before submission.
4. Confirm no billed date of service falls within a Part A covered stay.
5. Enter B4199 with one unit for each covered day in the billing period.
6. Bill lipids on their own line under B4185 or B4187, and leave the bundled components and B4216 off the claim.
7. Append KX only when the record supports every LCD L38953 criterion and the units match the order.
8. Report the ICD-10-CM code for the documented condition, and submit to the DME MAC for the beneficiary’s state.

Common denial reasons for B4199 and how to prevent them

Each denial below starts with a missing number or document that can be fixed before submission.

For a wider framework on rejections, the denial management guide covers appeal workflows and root-cause analysis. Modifier placement and diagnosis pairing are covered in the clean claim reference.

How claims management software reduces B4199 errors

The records behind a B4199 claim rarely sit together. The written order arrives in one inbox, the weight lives in the chart, and the delivery record sits with the pharmacy. Nobody divides grams by kilograms until a reviewer asks.

With Pabau’s claims management software, the order, the clinical notes, and the claim share one patient record. Billing staff can read the ordered grams and the current weight, then confirm the premix tier before the claim leaves the practice.

The result is fewer claims sent with a document missing, and a file that is ready when a reviewer asks for it. For a team billing high-protein regimens, that shows up as fewer recoupments.

Check the protein dose before the claim goes out

Pabau keeps the written order, the clinical notes, and the claim in one patient record. Your billing team can confirm the B4199 tier before submitting.

Book a demo

Conclusion

Two numbers decide a B4199 claim. The ordered protein must exceed 100 grams a day, and the unit count equals the number of covered days.

Orders at this dose also sit closest to the LCD’s 2.0 grams per kilogram ceiling. Weight on file is therefore as important as the order itself.

Put the gram dose and the weight on every order, count units by the day, and keep the order and delivery record with the claim. Book a demo to see how Pabau keeps orders, notes, and claims together for parenteral nutrition billing.

Continue your research

Ordering 74 to 100 grams of protein a day? HCPCS code B4197 covers the premix tier directly below B4199.

Ordering 52 to 73 grams of protein a day? HCPCS code B4193 explains the same per-day unit rule for the middle tier.

Billing a home-mix regimen instead? HCPCS code B4216 covers the additives billed with home-mix solutions.

Coding a solution under 10 grams of protein? HCPCS code B9999 covers the miscellaneous parenteral code.

Need to understand denial patterns across codes? Denial management in healthcare covers root-cause analysis and appeals for DMEPOS claims.

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