HCPCS Level II modifier
Modifier NB
Modifier NB is a HCPCS Level II modifier. CMS describes it as: Nebulizer system, any type, FDA-cleared for use with specific drug.
Source: CMS HCPCS Level II, October 2026 file dated September 23, 2026. Publisher page
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- Modifier
- NB
- Type
- HCPCS Level II modifier, maintained by CMS
- CMS description
- Nebulizer system, any type, FDA-cleared for use with specific drug
- Claim form
- CMS-1500 item 24D, up to four modifiers per line. 837P SV101-3 to SV101-6.
- Guidance
- CMS HCPCS quarterly update
Related modifiers
- NRNew when rented (use the 'NR' modifier when DME which was new at the time of rental is subsequently purchased)
- N3Group 3 oxygen coverage criteria met
- NUNew equipment
- N2Group 2 oxygen coverage criteria met
- P1A normal healthy patient
- N1Group 1 oxygen coverage criteria met
- P2A patient with mild systemic disease
- MSSix month maintenance and servicing fee for reasonable and necessary parts and labor which are not covered under any manufacturer or supplier warranty
Related pages
Questions
What does modifier NB mean?
Modifier NB is a HCPCS Level II modifier. CMS describes it as: Nebulizer system, any type, FDA-cleared for use with specific drug.
Is modifier NB a CPT or a HCPCS modifier?
NB is a HCPCS Level II modifier from the CMS quarterly HCPCS file. Two-digit numeric modifiers, such as 25 or 59, are CPT modifiers.
Where does modifier NB go on a claim?
On the CMS-1500 it goes in item 24D next to the procedure code. Each line holds up to four modifiers. On an 837P it goes in SV101-3 to SV101-6.
What denial comes back when a modifier is wrong?
A missing or mismatched modifier often comes back as CARC 4. A modifier that was not valid on the date of service comes back as CARC 182. A bundling edit the modifier should have bypassed comes back as CARC 97 or 236.