CPT code 86666: Ehrlichia antibody, ehrlichia-specific antibodies2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Laboratory testing for antibodies to tick-transmitted Ehrlichia supports evaluation of possible infection and is reported when the assay targets this organism.
Medicare pays $10.18 for 86666 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
$10.18
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 86666 covers
Code 86666 identifies laboratory analysis for antibodies to Ehrlichia, bacteria transmitted by ticks. It is used in evaluating possible Ehrlichia infection and measures the antibody response to that organism. A clinical laboratory performs and reports the assay for the ordering clinician. Select this code when the antibody test targets Ehrlichia; a test directed at another infectious agent requires its own code.
Medicare pays this code through the CLFS at one national amount in every state and locality, with no office-versus-facility difference. The 2026 national CLFS amount is $10.18, unchanged since 2020. The test is paid only through the CLFS, with no separate physician interpretation component 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 86666
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 86666. 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 86666 with status X (excluded by statute), so the test itself is paid only from the CLFS.
86666 on the lab fee schedule since 2020
86666 · CLFS 2026 Q4 (current)
$10.18
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.
86666 compared with similar tests
- 86618Lyme antibodyLyme disease antibody$17.03
- Code 86666 is for Ehrlichia antibodies; 86618 is for Lyme disease antibodies. Select according to the organism tested.
- 86757Rickettsia antibody$19.35
- Code 86666 evaluates antibodies to Ehrlichia, while 86757 is for Rickettsia antibody testing. They target different organisms.
- 86753Protozoan antibodyNot otherwise specified$12.39
- Code 86666 is for Ehrlichia antibody testing; 86753 is for Babesia antibody testing. They target different organisms.
86666 billing questions
What does code 86666 identify?
It identifies laboratory analysis for antibodies to Ehrlichia, bacteria transmitted by ticks.
How does this differ from Lyme antibody testing?
Code 86666 is for Ehrlichia antibodies; 86618 is for Lyme disease antibodies. Select the code for the organism targeted by the test.
Is a physician interpretation billed separately?
No separate physician interpretation component is payable for this code; Medicare pays it through the CLFS.
Does the Medicare payment vary by location or setting?
No. The CLFS amount is national and applies across localities, with no office-versus-facility 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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