HCPCS Level II drug code
Q0166 — Granisetron hydrochloride, 1 mg, oral, fda approved prescription anti-emetic, for use as a complete therapeutic substitute for an iv anti-emetic at the time of chemotherapy treatment, not to exceed a 24 hour dosage regimen
In short
Q0166 is the HCPCS Level II code for granisetron hydrochloride, 1 mg, oral, fda approved prescription anti-emetic, for use as a complete therapeutic substitute for an iv anti-emetic at the time of chemotherapy treatment, not to exceed a 24 hour dosage regimen. CMS assigns NDCs for Granisetron HCl to it. One billing unit is 1 mg. The Medicare Part B payment limit is $0.774 per unit (October 1, 2026 through December 31, 2026).
Code
CMS HCPCS file- Descriptor
- Granisetron hydrochloride, 1 mg, oral, fda approved prescription anti-emetic, for use as a complete therapeutic substitute for an iv anti-emetic at the time of chemotherapy treatment, not to exceed a 24 hour dosage regimen
- Short descriptor
- Granisetron hcl 1 mg oral
- Code set
- HCPCS Level II, maintained by CMS
- Effective
- Jan 1, 2009
The billing unit is read from the descriptor. Confirm it against the CMS file before billing.
Medicare Part B payment limit
CMS ASP fileEffective October 1, 2026 through December 31, 2026. Payment allowance limits subject to the ASP methodology are based on 2Q26 ASP data. CMS note: Added October 2026. A payment limit is not a coverage decision; the Medicare contractor decides coverage. CMS ASP pricing files
Units and claim line
Units = dose given ÷ 1 mg. For example, 100 mg is 100 units. Enter the dose to get the units and the NDC line for the CMS-1500 and the 837P.
Enter the dose given to build the claim line.
NDCs billed under Q0166
CMS’s ASP NDC–HCPCS crosswalk (effective October 1, 2026 through December 31, 2026) assigns 2 NDCs to Q0166 for Granisetron HCl. Billing units per package are CMS’s figures for this code’s unit.
| Drug | NDC (11-digit) | Labeler | Package | Billing units per package |
|---|---|---|---|---|
| Granisetron HCl | 51991-0735-20 | Breckenridge Pharmaceutical, Inc. | 20 | 20 |
| Granisetron HCl | 51991-0735-32 | Breckenridge Pharmaceutical, Inc. | 2 | 2 |
Q0166: common questions
- Is Q0166 a CPT code?
- No. Q0166 is a HCPCS Level II code, maintained by CMS, that identifies the drug supplied. CPT codes are five-digit numbers from the AMA that describe services. Giving the drug, for example an injection or infusion, is usually reported with a separate CPT administration code. CPT codes for drug administration.
- What NDCs are billed under Q0166?
- CMS's ASP crosswalk for October 1, 2026 through December 31, 2026 lists 2 NDCs under Q0166, for Granisetron HCl. The table on this page shows each one with its billing units per package.
- What is the Medicare payment limit for Q0166?
- $0.774 per 1 mg, effective October 1, 2026 through December 31, 2026, from CMS's Part B drug payment limit file. Multiply by the units billed for the allowed amount before deductible and coinsurance. It is not a coverage decision.
- What is one billing unit of Q0166?
- One unit of Q0166 is 1 mg, as stated in the code's descriptor. Units to report = dose given ÷ 1 mg. J-code billing units.