CPT 84443: thyroid stimulating hormone (TSH) blood test. What Medicare pays and what to ask
The TSH test is the usual first check of thyroid function. Here is what 84443 covers and the Medicare lab rate.
What this code means
CPT 84443 measures TSH, the hormone that tells the thyroid how much to produce.
It is the most common first test for thyroid problems and is also used to monitor thyroid medication.
Why the bill can be much higher than the Medicare rate
Like other lab tests, it is billed with a separate blood draw charge.
The Medicare lab rate is only a few dollars for this test, so multiples on hospital bills can look very large.
| If a line is billed at | It would be |
|---|---|
| 5x the Medicare rate | $84.00 |
| 10x the Medicare rate | $168.00 |
| 20x the Medicare rate | $336.00 |
The Medicare rate is a published benchmark, not a legal ceiling on what a provider may charge. Our free scan flags a line as worth a closer look when it is billed at more than 10 times the Medicare rate.
Questions worth asking before you pay
- Was the TSH test run once on this date?
- Were other thyroid tests added, and were they ordered?
- Is the blood draw billed only once?
Check every line against the official Medicare rates in about a minute. The scan is free.
Related codes
Source: Medicare Clinical Laboratory Fee Schedule (CMS, 2026), national payment limit. Last updated October 2026. This page is general information, not legal or medical advice. Rates change each year and a hospital bill can include charges that the benchmark does not cover.