CPT code 84311: Spectrophotometry, unspecified analyte2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Chemical analysis by spectrophotometry reports light-based testing for an analyte not represented by a more specific assay code.
Medicare pays $8.10 for 84311 under the 2026 Clinical Laboratory Fee Schedule: one national amount, the same in every state and setting.
Medicare lab fee · CLFS 2026 Q4
National CLFS amount
$8.10
In effect since Jan 1, 2026. The same amount in every state, payment locality and setting.
- Geographic adjustment
- None
- Office vs facility
- Same
- Since 2020
- Unchanged
- CMS updates
- Quarterly
Medicare pays the lesser of the lab’s charge and this amount. Patients usually owe no Part B deductible or coinsurance for covered clinical lab tests.
On this page 7 sections
What 84311 covers
84311 reports chemical analysis performed using spectrophotometry, a light-based laboratory method. It is used for an analyte that is not represented by a more specific assay code. The laboratory report should identify the measured analyte and document the spectrophotometric method, linking the reported service to this code. Clinical laboratories perform and report this testing.
Medicare pays 84311 only through the Clinical Laboratory Fee Schedule (CLFS); the code is excluded by statute from the physician fee schedule. The 2026 national CLFS amount is $8.10, unchanged from 2020 through 2025. This single amount applies in every state and locality, without geographic adjustment or an office-versus-facility payment difference. Medicare recorded 87,139 office services and no facility services for this code in 2024.
This summary was written with AI assistance from CMS Clinical Laboratory Fee Schedule data. Amounts on this page come directly from CMS files.
How Medicare pays 84311
Clinical lab tests aren’t priced like physician services. They’re paid from their own fee schedule, with its own rules. See the whole lab fee schedule.
One national amount
CMS sets a single Clinical Laboratory Fee Schedule amount for 84311. There’s no geographic (GPCI) adjustment, so it pays the same in every state and payment locality.
No office or facility rate
Lab tests aren’t built from relative value units, so there’s no office and facility split: the place of service doesn’t change the CLFS amount.
Updated every quarter
CMS republishes the CLFS each quarter. New tests, often proprietary laboratory analyses (PLA codes), join during the year; existing amounts are updated each January.
Excluded from the physician fee schedule
The physician fee schedule lists 84311 with status X (excluded by statute), so the test itself is paid only from the CLFS.
84311 on the lab fee schedule since 2020
84311 · CLFS 2026 Q4 (current)
$8.10
Unchanged since Jan 1, 2020
27 quarterly CLFS releases on file, first CLFS 2020 Q1. A code missing from a quarter wasn’t on that release.
84311 compared with similar tests
- 84300Urine sodiumUrine specimen$5.06
- 84300 identifies a urine sodium assay. 84311 reports spectrophotometric chemical analysis for an analyte not represented by a more specific assay code.
- 84302Sweat sodiumQuantitative sweat measurement$4.86
- 84302 identifies a sweat sodium assay. 84311 reports spectrophotometric chemical analysis for an analyte not represented by a more specific assay code.
- 84375Sugar chromatographyTLC or paper method$39.00
- 84375 identifies a chromatogram assay for sugars. 84311 identifies chemical analysis by spectrophotometry for an analyte not represented by a more specific assay code.
- 84378Sugar assaySingle, quantitative$11.53
- 84378 identifies quantitative testing for a single sugar. 84311 reports spectrophotometric chemical analysis for an analyte not represented by a more specific assay code.
84311 billing questions
When should 84311 be selected instead of a code for a named analyte?
Use 84311 for chemical analysis by spectrophotometry when no more specific assay code represents the analyte. A test identified by a specific analyte code should be reported with that code.
What should the laboratory record support?
The record should identify the analyte measured and support that the chemical analysis was performed using spectrophotometry.
Does Medicare pay 84311 under the physician fee schedule?
No. Medicare pays 84311 through the CLFS; the code is excluded by statute from the physician fee schedule.
Does payment vary by locality or setting?
No. One national CLFS amount applies in every state and locality, with no geographic adjustment or office-versus-facility payment difference.
Where this amount comes from
FeeBase reads lab amounts directly from the CMS Clinical Laboratory Fee Schedule file for the quarter: one row per code, with its payment indicator and national amount. Contractor-priced tests are labeled, never given a made-up amount. Amounts are Medicare payment limits, not a patient’s bill or a commercial rate.
CMS CLFS 2026 Q4 · effective Oct 1, 2026 through the day before Jan 1, 2027
Show the CMS file line behind this amount
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