CPT code 87798: Infectious agent test, amplified probe, each organism2026 Medicare lab fee · Clinical Laboratory Fee Schedule
This amplified-probe nucleic-acid test detects an infectious organism not otherwise specified and is reported separately for each organism tested.
Medicare pays $35.09 for 87798 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
$35.09
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
- QW · CLIA-waived test
- $35.09
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 87798 covers
87798 identifies nucleic acid from an infectious organism using an amplified probe when no more specific organism code describes the test. Report the code for each organism tested. It represents organism detection by amplified probe, rather than direct-probe or quantitative testing. Amplified-probe tests for Chlamydia trachomatis and Neisseria gonorrhoeae have organism-specific codes, 87491 and 87591, respectively. A CLIA-waived version may be performed by a site holding a CLIA certificate of waiver.
Report one unit for each organism tested, not for each specimen. Append modifier QW for the CLIA-waived version when applicable. Medicare pays 87798 under the CLFS at one national amount across states and localities, without an office or facility difference. The 2026 national amount is $35.09 and has remained unchanged since 2020. The code is excluded from the physician fee schedule and is paid only from the CLFS.
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 87798
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 87798. 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 87798 with status X (excluded by statute), so the test itself is paid only from the CLFS.
CLIA-waived version (QW)
CMS also lists 87798 with modifier QW, the version labs holding a CLIA certificate of waiver bill. It pays $35.09.
87798 on the lab fee schedule since 2020
87798 · CLFS 2026 Q4 (current)
$35.09
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.
87798 compared with similar tests
- 87797Agent detectionDirect probe, each organism$30.03
- 87797 identifies an infectious agent using a direct-probe technique. Use 87798 when the assay uses an amplified probe.
- 87799Nucleic acid testQuantitative per organism$42.84
- 87799 is for quantitative infectious-agent detection. Use 87798 for detection by amplified probe when quantitative testing is not reported.
- 87491Chlamydia testAmplified nucleic acid detection$35.09
- 87491 is the organism-specific amplified-probe code for Chlamydia trachomatis. Use 87798 for an organism not described by a more specific code.
87798 billing questions
How many units should be reported?
Report one unit for each organism tested. The code represents an organism count, not a specimen count.
When should modifier QW be used?
Use QW for the CLIA-waived version when the testing site holds a CLIA certificate of waiver.
How does 87798 differ from 87797?
87798 describes amplified-probe testing; 87797 describes direct-probe testing. Select the code that matches the method performed.
When is 87799 more appropriate?
87799 is for quantitative detection. Use 87798 for detection by amplified probe when quantitative testing is not the service reported.
How does Medicare pay this test?
Medicare pays 87798 from the CLFS at one national amount, with no locality or office/facility adjustment. It is excluded from the physician fee schedule.
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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