CPT code 86309: Mononucleosis titer, quantitative antibody level2026 Medicare lab fee · Clinical Laboratory Fee Schedule
A heterophile antibody titer measures mononucleosis-associated antibodies when evaluation calls for an antibody level rather than a screening result.
Medicare pays $6.47 for 86309 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
$6.47
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 8 sections
What 86309 covers
Code 86309 identifies a laboratory determination of heterophile antibody level reported as a titer. The test is associated with evaluation for infectious mononucleosis. A clinician may select a titer when an antibody level is needed rather than a heterophile antibody screen. The distinction is the reported level, not simply screening for heterophile antibodies.
Report 86309 for the titer determination; 86308 identifies a heterophile antibody screen, while 86310 identifies heterophile antibody absorption. Medicare pays 86309 through the CLFS at one national amount that applies across states and localities, without geographic or office/facility adjustment. The 2026 national CLFS amount is $6.47, unchanged from 2020 through 2026. Medicare pays the test only through the CLFS, not 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 86309
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 86309. 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 86309 with status X (excluded by statute), so the test itself is paid only from the CLFS.
86309 on the lab fee schedule since 2020
86309 · CLFS 2026 Q4 (current)
$6.47
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.
86309 compared with similar tests
86309 billing questions
When should 86309 be reported instead of 86308?
Report 86309 when the laboratory determines a heterophile antibody titer. Code 86308 identifies a heterophile antibody screen.
How does 86309 differ from 86310?
Code 86309 identifies a heterophile antibody titer; 86310 identifies heterophile antibody absorption.
Does Medicare pay 86309 under the physician fee schedule?
No. Medicare pays this test through the CLFS.
Does the CLFS payment vary by location or setting?
No. One national CLFS amount applies across locations, with no geographic or office/facility adjustment.
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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