HCPCS J1100: Dexamethasone Sodium Phosphate Injection
HCPCS J1100 reports injectable dexamethasone sodium phosphate, per 1 mg — a corticosteroid used for inflammation, allergic reactions, and many other indications. As a Part B drug it is paid at approximately ASP plus 6%, billed per unit with the NDC. Report drug waste with JW and no-waste with JZ.
- Code type
- HCPCS Level II drug (per 1 mg)
- Priced under
- Part B: ~ASP + 6%
- Billed per
- Per 1 mg unit, with the NDC
- Waste modifier
- JW (discarded) / JZ (no waste)
What is HCPCS J1100 used for?
HCPCS J1100 reports injectable dexamethasone sodium phosphate, per 1 mg — a potent corticosteroid (brand Decadron among others) used for inflammation, severe allergic reactions, cerebral edema, nausea, and many other indications, given IM, IV, or by local injection. J1100 bills the drug; the injection administration (96372) is billed separately.
How do you count units for J1100?
The descriptor is per 1 mg, so units equal the milligrams given:
| Dose given | Units of J1100 |
|---|---|
| 4 mg | 4 |
| 8 mg | 8 |
| 10 mg | 10 |
Example: a 10 mg IM dexamethasone dose is billed as J1100 x10 units plus 96372 for the administration.
How is J1100 priced, and why the NDC?
As a Medicare Part B separately payable drug, dexamethasone sodium phosphate is reimbursed at roughly ASP plus 6 percent. The average sales price is set by CMS and updated quarterly, so the dollar rate moves every quarter — this card describes the method, not a fixed price. The NDC is required on the claim line to identify the exact concentration, vial size, and manufacturer for correct pricing.
How do JW and JZ modifiers apply to J1100?
- JW — reports the discarded milligrams from a single-dose vial on a separate line.
- JZ — attests no drug was discarded.
One of the two is required on separately payable single-dose-container drugs. The same ASP-and-waste framework applies to J1885, J3301, and J0696. For the payable administration services, check locality rates in the Medicare fee calculator under Part B.
Frequently asked questions
J1100 is per 1 mg, so units equal the milligrams administered. A 4 mg dose is 4 units; a 10 mg dose is 10 units. Because the unit is small, unit math is a common error — count carefully and include the NDC on the drug line.
As a Medicare Part B separately payable drug, dexamethasone sodium phosphate is reimbursed at approximately ASP plus 6 percent. CMS updates the average sales price quarterly, so the exact dollar rate changes each quarter. Bill per 1 mg unit and let the payer apply the current ASP amount.
For single-dose vials, use JW on a separate line for the discarded milligrams and JZ when nothing is discarded. One is required on separately payable single-dose-container drugs. Multi-dose dexamethasone vials follow different waste handling and generally do not use JW/JZ.
Sources & further reading
Reviewed by the ImmediCare Solutions RCM team
Certified billers and coders handling claims across 50+ specialties nationwide. This entry is reviewed against current payer policy and CMS rules. Last review: Jul 5, 2026.
Stop losing revenue to problems like this.
A free billing audit shows exactly where your practice is leaking money — no cost, no commitment.
