CPT code 86335: Immunofixation, concentrated urine or CSF2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Immunofixation electrophoresis of concentrated urine, cerebrospinal fluid, or another fluid helps characterize immunoglobulin bands in selected diagnostic workups.
Medicare pays $29.35 for 86335 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
$29.35
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 8 sections
What 86335 covers
This laboratory service uses immunofixation electrophoresis on a concentrated body fluid, such as urine or cerebrospinal fluid, to characterize immunoglobulins in abnormal protein bands. Urine testing may help identify monoclonal immunoglobulin light chains during evaluation of plasma cell disorders. The test is performed by a clinical laboratory when a clinician needs this analysis of a non-serum fluid; serum immunofixation is reported separately.
Report the service for the concentrated-fluid analysis performed. Medicare pays the test under the CLFS at one national amount in every state and locality, with no office or facility payment difference. The 2026 national CLFS amount is $29.35, unchanged since 2020. A physician’s separate interpretation may be billed with modifier 26 and is payable under the physician fee schedule.
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 86335
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 86335. 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 86335 with status X (excluded by statute), so the test itself is paid only from the CLFS.
Physician interpretation (modifier 26)
A physician’s interpretation is billed separately with modifier 26 and paid under the physician fee schedule: $17.70 nationally in the office, before locality adjustment.
86335 on the lab fee schedule since 2020
86335 · CLFS 2026 Q4 (current)
$29.35
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.
86335 compared with similar tests
- 86334ImmunofixationSerum specimen$22.34
- Both describe immunofixation electrophoresis, but 86334 is for serum. Use 86335 for concentrated urine, CSF, or another fluid.
- 86320ImmunoelectrophoresisSerum$29.92
- This code describes serum immunoelectrophoresis, not immunofixation of a concentrated non-serum fluid.
- 86325ImmunoelectrophoresisConcentrated nonserum fluids$23.13
- This is another immunoelectrophoresis service; 86335 specifically identifies immunofixation performed on concentrated fluid.
86335 billing questions
When should this code be chosen instead of 86334?
Use this code for immunofixation electrophoresis of a concentrated fluid such as urine or CSF. Code 86334 is for serum immunofixation.
Does this code describe urine testing for monoclonal light chains?
Yes. Concentrated urine immunofixation can help characterize monoclonal immunoglobulin light chains in a plasma cell disorder workup.
Can a physician bill separately for interpretation?
A separate physician interpretation may be billed with modifier 26 and is payable under the physician fee schedule.
Does Medicare pay different amounts by location or setting?
No. The test is paid under the CLFS at one national amount, without a locality or office-versus-facility difference.
Is this the correct code for serum immunofixation?
No. Serum immunofixation is reported with 86334; this code is for concentrated urine, CSF, or another fluid.
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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