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HCPCS Q5166 · Level II · Part B drug

Q5166: denosumab-desu, HCPCS Level II drug code

Compiled from CMS files by the QuickIntell RCM Editorial Team · Data effective · Method: reference methodology · Report a data correction

Data currency: OPPS Addendum B: October 2026 (effective October 1, 2026); OPPS NDC-HCPCS crosswalk: October 2026 (effective October 1, 2026); NCCI MUE tables: 2026 Q4 (effective October 1, 2026); NCCI PTP edits: v323r0 (2026 Q4) (effective October 1, 2026); ASC Addendum BB (covered ancillary services): October 2026 (effective October 1, 2026). Next CMS release: January 1, 2027 (quarterly update).

Key facts for Q5166

Billing unit
1 mg
Inj, denosumab-desu, 1 mg
OPPS payment rate
$29.72
no ASP limit; SI K, October 2026
Practitioner MUE
none published
CMS publishes no MUE for this code
OPPS status
SI K
APC 0974
NCCI exposure
no PTP pairs
Coverage articles
1
5 states

TL;DR

HCPCS Q5166 is the Level II code for Injection, denosumab-desu (osvyrti/jubereq), biosimilar, 1 mg, billed per 1 mg. CMS publishes no ASP payment limit for it; hospital outpatient departments are paid separately under OPPS (status indicator K, $29.72 per billing unit in October 2026). As a biosimilar it has its own code and ASP; the reference product cannot be billed under this code, and the JZ or JW modifier rules for discarded amounts apply per single-dose vial. With a 1 mg billing unit, a single administration can be hundreds of units; the unit count on the claim must equal the milligrams given, and rounding rules for partial units follow the contractor's guidance. Other HCPCS codes whose descriptor names denosumab: Q5167 (biosimilar denosumab-qbde (Enoby/Xtrenbo) from Hikma Pharmaceuticals USA Inc.; billed per 1 mg); Q5162 (biosimilar denosumab-nxxp (Bildyos/Bilprevda) from Organon LLC; billed per 1 mg); Q5161 (biosimilar denosumab-kyqq (Aukelso/Bosaya) from Biocon Biologics Inc.; billed per 1 mg); Q5158 (biosimilar denosumab-bnht (Bomyntra/Conexxence) from Fresenius Kabi USA, LLC; billed per 1 mg); Q5157 (biosimilar denosumab-bmwo (Stoboclo/Osenvelt) from Celltrion USA, Inc.; billed per 1 mg); Q5136 (biosimilar denosumab-bbdz (Jubbonti/Wyost) from Sandoz Inc.; billed per 1 mg). 1 Medicare coverage article lists the code across 5 states, including A52399.

Medicare payment: OPPS rate (no ASP limit)

Q5166 does not appear in the October 2026 Part B ASP payment limit file. CMS pays it separately to hospital outpatient departments under OPPS with status indicator K in APC 0974, at a national unadjusted rate of $29.72 per 1 mg. Status K is a separately paid, non-pass-through drug or biological, including therapeutic radiopharmaceuticals. In a physician office the Medicare contractor prices the drug, often from invoice; commercial and Medicaid payers set their own rates.

NDC to HCPCS billing-unit conversion

The October 2026 OPPS crosswalk lists no NDC for Q5166. Report the NDC from the product label and confirm the units conversion from the HCPCS descriptor (Injection, denosumab-desu (osvyrti/jubereq), biosimilar, 1 mg).

Medically Unlikely Edits (MUE)

CMS does not publish an MUE for Q5166 in the 2026 Q4 tables. Some MUE values are confidential and applied without publication, so unit limits can still deny; document the dose and the units calculation on every claim.

MUE for Q5166 in every setting opens the lookup with this code filled in, next to any other code on the same claim.

NCCI edits and add-on relationships

No active practitioner PTP pair lists Q5166 as a column-1 or column-2 code in v323r0. Drug supply codes are rarely bundled; the administration codes billed with them are where PTP edits usually apply.

The counts above are exposure, not answers for a specific claim. Check Q5166 against another code to see whether a given pair bundles, which code is paid and whether a modifier can separate them.

Q5166 is neither an add-on code nor a designated primary code in the 2026 Q4 NCCI add-on edit file.

Medicare coverage articles

1 current Medicare Administrative Contractor article lists Q5166 in their HCPCS tables, covering 5 states. Each article carries the covered and non-covered ICD-10 codes that medical-necessity denials (CARC 50) are adjudicated against.

Billing and Coding Articles listing Q5166
ArticleTitleContractor(s)StatesRelated LCD
A52399Billing and Coding: Denosumab (Prolia®, Xgeva®, Jubbonti®) and biosimilarsWellpoint FederalCT IL MN NY WIL33394

Local coverage policies that list Q5166

1 active Local Coverage Determination lists Q5166 in the policy or in its billing and coding article. Each applies only in its contractor's jurisdiction; check the one for the state where the drug is administered.

Hospital outpatient (OPPS) status

In the October 2026 OPPS Addendum B, Q5166 carries status indicator K and is assigned to APC 0974, with a published national unadjusted payment of $29.72. Status K means the drug is paid separately under OPPS rather than packaged into the procedure.

Ambulatory surgical center (ASC) payment

In the October 2026 ASC Addendum BB (covered ancillary services), Q5166 carries payment indicator K2, which CMS defines as "Drugs, biologicals, and radiopharmaceuticals paid separately when provided integral to a surgical procedure on ASC list; payment based on OPPS rate". The national ASC payment is $29.72 per 1 mg, paid only when the drug is furnished integral to a covered surgical procedure.

Common denials for Q5166 and how to prevent them

CARC 16 · M119

NDC missing, invalid or not matched to the HCPCS code

CARC 151 · N362

units billed exceed the MUE for the date of service

CARC 50 · N115

diagnosis not covered by the applicable coverage article or LCD

How QuickIntell checks Q5166 before the claim leaves

QuickCode validates the NDC-to-unit conversion against the current OPPS NDC-HCPCS crosswalk, checks units against every published MUE setting and flags PTP and add-on conflicts on the same claim. QuickRCM routes CARC 16, 151 and 50 denials on drug lines with the matching coverage article attached so the appeal starts with evidence.

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Frequently asked questions — HCPCS Q5166

What does HCPCS code Q5166 describe?

Q5166 is defined by CMS as "Injection, denosumab-desu (osvyrti/jubereq), biosimilar, 1 mg". Each billing unit represents 1 mg, so the units reported on the claim must equal the dose administered divided by that unit.

Is Q5166 a CPT code?

No. Q5166 is a HCPCS Level II code, the letter-plus-four-digit set CMS maintains for drugs such as denosumab-desu; CPT codes are five-character codes maintained by the AMA. On a Part B claim Q5166 reports the drug itself in 1 mg units, and the administration is billed on its own line.

What does Medicare pay for Q5166 in a hospital outpatient department?

Q5166 has no Part B ASP limit; the October 2026 OPPS Addendum B pays it separately under status K, APC 0974, at $29.72 per 1 mg, and ASC Addendum BB gives it payment indicator K2 at $29.72.

Does Q5166 have NCCI bundling edits?

No active practitioner PTP pairs list Q5166 as a column-1 or column-2 code in the v323r0 release.

Q5166 vs Q5167: what is the difference?

Both are HCPCS Level II codes whose descriptor names denosumab. What sets Q5167 apart: biosimilar denosumab-qbde (Enoby/Xtrenbo) from Hikma Pharmaceuticals USA Inc.; billed per 1 mg. Q5166 is billed per 1 mg, OPPS rate $29.72; Q5167 is billed per 1 mg, limit $7.681. Report the code whose descriptor matches the product and setting in the record.

Q5166 vs Q5162: what is the difference?

Both are HCPCS Level II codes whose descriptor names denosumab. What sets Q5162 apart: biosimilar denosumab-nxxp (Bildyos/Bilprevda) from Organon LLC; billed per 1 mg. Q5166 is billed per 1 mg, OPPS rate $29.72; Q5162 is billed per 1 mg, limit $15.336. Report the code whose descriptor matches the product and setting in the record.

Which Medicare coverage articles mention Q5166?

1 current Billing and Coding Article in the Medicare Coverage Database lists Q5166, covering 5 states: A52399 (Billing and Coding: Denosumab (Prolia®, Xgeva®, Jubbonti®) and biosimilars).

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-10. Verify against the primary file before billing or contracting decisions. The reference methodology explains how each figure is computed from these files.

Disclaimer

This page is an operational reference compiled from CMS publications: the Medicare Part B drug payment limit and NDC crosswalk files, NCCI MUE and add-on edit tables, aggregate PTP statistics, OPPS Addendum B, ASC Addendum BB and the Medicare Coverage Database. Payment limits and rates are Medicare national amounts; commercial and Medicaid payers differ. CPT codes are shown as numbers only; CPT descriptors are copyright AMA. Nothing here is legal, clinical or billing advice.

Found a figure that does not match the CMS file? Report a data correction with the CMS file and the value you expected; the request reaches the editorial team through the contact form.