CPT code 84443: TSH test, thyroid-stimulating hormone2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Measures thyroid-stimulating hormone in a blood sample to evaluate thyroid function or monitor treatment for thyroid disease.
Medicare pays $16.80 for 84443 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
$16.80
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
- $16.80
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 84443 covers
This blood test measures thyroid-stimulating hormone (TSH), a pituitary hormone used to assess how the thyroid is functioning. Clinicians commonly order it when evaluating suspected hypothyroidism or hyperthyroidism and when monitoring patients receiving thyroid hormone treatment. Hospital laboratories, independent laboratories, and office-based laboratories may perform the assay.
Report the TSH assay performed; it is a distinct measurement from thyroid hormone tests such as free or total thyroxine. CMS also recognizes a CLIA-waived version reported with modifier QW for eligible sites holding a CLIA certificate of waiver. Medicare pays the test only through the CLFS. The 2026 national CLFS amount is $16.80, unchanged from 2020 through 2026; the same amount applies across localities, without an office or facility difference. The physician fee schedule does not pay separately for this test.
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 84443
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 84443. 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 84443 with status X (excluded by statute), so the test itself is paid only from the CLFS.
CLIA-waived version (QW)
CMS also lists 84443 with modifier QW, the version labs holding a CLIA certificate of waiver bill. It pays $16.80.
84443 on the lab fee schedule since 2020
84443 · CLFS 2026 Q4 (current)
$16.80
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.
84443 compared with similar tests
- 84439Free T4Unbound thyroxine$9.02
- This code measures TSH; 84439 measures free thyroxine. They are different analytes and may be ordered together.
- 84436Total T4Total thyroxine$6.87
- This code measures TSH; 84436 measures total thyroxine. Select the code for the assay actually performed.
- 84445TSI assayStimulating thyroid antibodies$50.86
- This code measures pituitary TSH, whereas 84445 measures thyroid-stimulating immunoglobulin, an antibody.
84443 billing questions
When should this code be selected instead of a thyroxine code?
Use this code for the TSH assay. Codes 84436 and 84439 measure total and free thyroxine, respectively, and represent different analytes.
Can TSH be reported with a free T4 test?
Yes. TSH and free T4 are separate assays and are commonly ordered together or performed through a reflex testing protocol.
When is modifier QW appropriate?
CMS lists a CLIA-waived version of this test with modifier QW. It identifies the waived version performed by a site holding a CLIA certificate of waiver.
Does Medicare pay this test under the physician fee schedule?
No. Medicare pays this assay through the CLFS, with one national amount that is the same across localities and settings.
Is a TSH result interchangeable with a TSI result?
No. TSH measures a pituitary hormone, while code 84445 measures thyroid-stimulating immunoglobulin, an antibody test used in evaluating autoimmune thyroid disease.
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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