S3645: Hiv-1 antibody testing of oral mucosal transudate
S3645 is a HCPCS Level II code for hiv-1 antibody testing of oral mucosal transudate. It belongs to the Temporary National Codes (Non-Medicare) section. Medicare does not pay it: see the coverage note below before you bill it.
Medicare coverage: Not payable by Medicare
Medicare does not pay this code. It may still be valid for another payer, but a Medicare claim carrying it will not be reimbursed.
From the coverage field of the CMS Alpha-Numeric HCPCS File, release 2026Q4-Oct. This states Medicare’s position on the code, not on your particular claim.
Physician fee schedule statusI
Not valid for Medicare purposes. Medicare uses another code.
Global period: XXX
Want the dollar amount for your locality? The fee calculator applies your GPCI and the current conversion factor.
The CMS record for S3645
- Long descriptor
- Hiv-1 antibody testing of oral mucosal transudate
- Short descriptor
- Hiv-1 antibody testing of or
- Added
- January 1, 2000
- BETOS
- Z2
- Pricing indicator
- 00: Not priced by Part B
The official wording. This is what the code means.
CMS's 28-character form, which is what shows up on a remittance advice.
When CMS introduced the code.
Berenson-Eggers Type of Service: CMS's own analytic grouping.
Service not separately priced by Part B, not covered, bundled into another service, or used by Part A only.
Codes adjacent to S3645
HCPCS has no hierarchy: related items simply sit next to each other in the numbering. If S3645 is not quite right, the correct code is very often within a few positions of it.
- S2411Fetoscopic laser therapy for treatment of twin-to-twin transfusion syndrome
- S2900Surgical techniques requiring use of robotic surgical system (list separately in addition to code for primary procedure)
- S3000Diabetic indicator; retinal eye exam, dilated, bilateral
- S3005Performance measurement, evaluation of patient self assessment, depression
- S3600Stat laboratory request (situations other than s3601)
- S3601Emergency stat laboratory charge for patient who is homebound or residing in a nursing facility
- S3620Newborn metabolic screening panel, includes test kit, postage and the laboratory tests specified by the state for inclusion in this panel (e.g., galactose; hemoglobin, electrophoresis; hydroxyprogesterone, 17-d; phenylalanine (pku); and thyroxine, total)
- S3630Eosinophil count, blood, direct
- S3650Saliva test, hormone level; during menopause
- S3652Saliva test, hormone level; to assess preterm labor risk
- S3655Antisperm antibodies test (immunobead)
- S3708Gastrointestinal fat absorption study
- S3721Prostate cancer antigen 3 (pca3) testingterminated
- S3722Dose optimization by area under the curve (auc) analysis, for infusional 5-fluorouracil
- S3800Genetic testing for amyotrophic lateral sclerosis (als)
- S3840Dna analysis for germline mutations of the ret proto-oncogene for susceptibility to multiple endocrine neoplasia type 2