CPT code 87324: C. difficile toxin test, stool toxin immunoassay2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Immunoassay detection of Clostridium difficile toxins in stool, reported when a laboratory tests for suspected C. difficile infection.
Medicare pays $11.98 for 87324 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
$11.98
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 87324 covers
This laboratory test uses an immunoassay to detect Clostridium difficile toxin or toxins in stool. The result is qualitative or semiquantitative. Laboratories report it when testing stool for suspected C. difficile infection, such as for a patient evaluated for diarrhea. It identifies toxin detection rather than culture or nucleic acid testing.
Report 87324 for the immunoassay test performed. Medicare pays the test only through the CLFS, with one national amount applying in every state and locality and no geographic or office-versus-facility adjustment. The 2026 national CLFS amount is $11.98, unchanged from 2020 through 2026. The code is excluded from the physician fee schedule by statute; Medicare payment is through the CLFS, not a separately payable physician interpretation component.
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 87324
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 87324. 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 87324 with status X (excluded by statute), so the test itself is paid only from the CLFS.
87324 on the lab fee schedule since 2020
87324 · CLFS 2026 Q4 (current)
$11.98
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.
87324 compared with similar tests
- 87493C. difficile testToxin-gene amplification$37.27
- Use 87324 for immunoassay detection of C. difficile toxins in stool; 87493 describes nucleic acid testing.
- 87328Cryptosporidium antigenImmunoassay detection$13.82
- Both are stool antigen immunoassays, but 87328 detects Cryptosporidium antigen rather than C. difficile toxins.
- 87338H. pylori antigenStool immunoassay$14.38
- Both involve stool antigen testing by immunoassay, but 87338 detects Helicobacter pylori antigen.
87324 billing questions
When should 87324 be reported instead of 87493?
Report 87324 for immunoassay detection of C. difficile toxins in stool. Code 87493 is for nucleic acid testing.
Does 87324 describe a stool culture?
No. It describes immunoassay detection of C. difficile toxins, not culture of the organism.
What specimen is tested?
The test detects C. difficile toxins in stool.
How does Medicare pay for 87324?
Medicare pays the test through the CLFS at one national amount across localities, without geographic or office-versus-facility adjustment.
Is physician interpretation separately payable under this code?
No. Medicare pays this test only through the CLFS; it is excluded from the physician fee schedule by statute.
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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