CPT code 87184: Disk susceptibility, up to 12 agents per plate2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Disk-method antimicrobial susceptibility testing assesses an isolate’s response to selected drugs and is reported per culture plate when 12 or fewer agents are tested.
Medicare pays $7.48 for 87184 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
$7.48
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 87184 covers
Disk-method antimicrobial susceptibility testing measures an isolate’s response to antimicrobial agents by placing disks on an inoculated culture plate and assessing the resulting growth-inhibition zones. A clinical microbiology laboratory generally performs the test on an organism recovered through culture. Clinicians use the findings to help select treatment for an infection; the drugs tested depend on the organism and clinical question.
Report 87184 per plate when 12 or fewer agents are evaluated by the disk method; do not count each disk as a separate unit. Medicare pays the test under the CLFS at one national amount in every locality, without geographic or office/facility adjustment. The 2026 national CLFS amount is $7.48, unchanged since 2020. The code is paid only from the CLFS and is excluded from 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 87184
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 87184. 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 87184 with status X (excluded by statute), so the test itself is paid only from the CLFS.
87184 on the lab fee schedule since 2020
87184 · CLFS 2026 Q4 (current)
$7.48
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.
87184 compared with similar tests
- 87181Agar susceptibilityPer antimicrobial agent$4.75
- Use 87184 for disk diffusion testing reported per plate. Use 87181 when the laboratory uses agar dilution and reports susceptibility per agent.
- 87186Susceptibility testMicrodilution or agar dilution$8.65
- 87184 describes the disk method; 87186 is for microdilution or agar dilution testing.
- 87187MLC susceptibilityMicrodilution or agar dilution$40.17
- 87187 identifies microdilution or agar dilution testing for minimum lethal concentration, rather than disk diffusion susceptibility testing.
87184 billing questions
When should the disk method be reported instead of an agar dilution method?
Report this code when the laboratory evaluates antimicrobial susceptibility using disks on a culture plate. Agar dilution is a different testing method and is reported under the code for that method.
What is the unit of service?
The unit is one plate, with 12 or fewer antimicrobial agents evaluated on that plate. Do not count each disk as a separate unit.
Is the original patient specimen tested directly?
The study is generally performed on an organism recovered in culture, rather than on the original specimen. The specimen source varies with the clinical infection being evaluated.
How is Medicare payment handled for this code?
Medicare pays this test under the CLFS. It is excluded from the physician fee schedule.
Does payment vary by locality or setting?
No. The CLFS amount is the same across localities, 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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