CPT code 86635: Coccidioides antibody, serologic test2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Coccidioides antibody testing detects the patient’s immune response and is reported when evaluating suspected coccidioidomycosis, including Valley fever.
Medicare pays $11.47 for 86635 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
$11.47
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 86635 covers
This serologic test detects antibodies to Coccidioides, the fungus that causes coccidioidomycosis, commonly called Valley fever. Clinicians may order it when a patient has compatible illness and exposure in an area where the fungus occurs, including the southwestern United States. The test supports evaluation of suspected infection; it measures the patient’s antibody response rather than detecting the fungus directly. Clinical laboratories perform and report the assay for ordering clinicians, including primary care, pulmonary, and infectious disease practices.
Report 86635 for the Coccidioides antibody test, not for a culture or direct organism-detection test. The code represents the antibody testing service; use the laboratory report and medical record to support the service billed. Medicare pays it through the CLFS, with one national amount for every state and locality and no office-versus-facility payment difference. The 2026 national CLFS amount is $11.47, unchanged since 2020.
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 86635
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 86635. 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 86635 with status X (excluded by statute), so the test itself is paid only from the CLFS.
86635 on the lab fee schedule since 2020
86635 · CLFS 2026 Q4 (current)
$11.47
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.
86635 compared with similar tests
- 86612Blastomyces antibody$12.90
- Choose 86635 for Coccidioides antibody testing and 86612 for Blastomyces antibody testing. The organism tested determines the code.
- 86628Candida antibodyAntibody to Candida$12.01
- 86628 is for Candida antibodies. It is not interchangeable with 86635, which identifies Coccidioides antibodies.
- 86641Cryptococcus antibody$14.41
- 86641 identifies Cryptococcus antibody testing; 86635 identifies Coccidioides antibody testing. Select according to the laboratory assay’s target.
86635 billing questions
When is 86635 appropriate?
Use it for laboratory testing of antibodies to Coccidioides when evaluating suspected coccidioidomycosis. It is not a code for testing antibodies to another infectious agent.
Is this an antibody test or a culture?
It represents antibody testing, which measures the patient’s immune response. A culture or other direct organism-detection method is a different service.
How does 86635 differ from 86612?
86635 identifies antibodies to Coccidioides; 86612 identifies antibodies to Blastomyces. Select the code for the organism tested.
Does Medicare pay 86635 under the physician fee schedule?
No. Medicare pays this test only through the CLFS, using one national amount across localities and care settings.
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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