HCPCS Level II modifier
Modifier BU
Modifier BU is a HCPCS Level II modifier. CMS describes it as: The beneficiary has been informed of the purchase and rental options and after 30 days has not informed the supplier of his/her decision.
Source: CMS HCPCS Level II, October 2026 file dated September 23, 2026. Publisher page
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- Modifier
- BU
- Type
- HCPCS Level II modifier, maintained by CMS
- CMS description
- The beneficiary has been informed of the purchase and rental options and after 30 days has not informed the supplier of his/her decision
- 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
- CAProcedure payable only in the inpatient setting when performed emergently on an outpatient who expires prior to admission
- BRThe beneficiary has been informed of the purchase and rental options and has elected to rent the item
- CBService ordered by a renal dialysis facility (RDF) physician as part of the ESRD beneficiary's dialysis benefit, is not part of the composite rate, and is separately reimbursable
- BPThe beneficiary has been informed of the purchase and rental options and has elected to purchase the item
- CCProcedure code change (use 'CC' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed)
- BOOrally administered nutrition, not by feeding tube
- CDAMCC test has been ordered by an ESRD facility or MCP physician that is part of the composite rate and is not separately billable
- BLSpecial acquisition of blood and blood products
Related pages
Questions
What does modifier BU mean?
Modifier BU is a HCPCS Level II modifier. CMS describes it as: The beneficiary has been informed of the purchase and rental options and after 30 days has not informed the supplier of his/her decision.
Is modifier BU a CPT or a HCPCS modifier?
BU 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 BU 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.