CPT code 87542: Legionella DNA, quantitative assay2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Quantitative nucleic-acid testing for Legionella pneumophila measures the organism’s DNA in a specimen when a quantitative result is needed.
Medicare pays $41.76 for 87542 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
$41.76
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 87542 covers
87542 represents nucleic-acid testing that quantifies Legionella pneumophila DNA. Its defining distinction from related Legionella tests is the quantitative result: 87540 represents direct-probe detection, while 87541 represents amplification-probe detection. The laboratory reports a measured amount of target DNA rather than a detection-only result. Clinicians use the quantitative result when evaluating suspected L. pneumophila infection. The code identifies the organism target and the quantitative nucleic-acid service.
Report 87542 for the quantitative L. pneumophila nucleic-acid assay, rather than 87540 or 87541 for direct-probe or amplification-probe detection. Medicare pays the test only through the CLFS. The 2026 national CLFS amount is $41.76, unchanged from 2020 through 2026; one amount applies across states and localities, with no geographic or office/facility adjustment. The code 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 87542
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 87542. 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 87542 with status X (excluded by statute), so the test itself is paid only from the CLFS.
87542 on the lab fee schedule since 2020
87542 · CLFS 2026 Q4 (current)
$41.76
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.
87542 compared with similar tests
- 87540Legionella DNADirect-probe detection$20.05
- 87540 represents direct-probe detection of L. pneumophila DNA. Use 87542 when the assay produces a quantitative result.
- 87541Legionella DNAAmplified probe$35.09
- 87541 represents amplification-probe detection of L. pneumophila DNA. Use 87542 for quantitative testing.
- 87552Mycobacteria quantificationQuantitative nucleic-acid assay$42.84
- 87552 quantifies Mycobacteria DNA rather than L. pneumophila DNA. Select according to the organism tested.
87542 billing questions
When should 87542 be selected instead of 87540 or 87541?
Use 87542 when the L. pneumophila nucleic-acid test produces a quantitative result. Codes 87540 and 87541 represent direct-probe and amplification-probe detection, respectively.
Does 87542 identify the organism or quantify it?
It quantifies Legionella pneumophila DNA. Its distinguishing feature is a quantitative result rather than detection alone.
How does Medicare pay 87542?
Medicare pays the test through the CLFS, with one amount across states and localities and no geographic or office/facility adjustment.
Is 87542 paid under the physician fee schedule?
No. Medicare pays this test only through the CLFS; 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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