Lab · CPT 84443

What is CPT code 84443?

Thyroid test (TSH).

By Justin Feldstein · Reviewed 2026-06-15

What it covers

A blood test that measures TSH, a hormone your brain uses to tell the thyroid how hard to work. It's the standard first check of whether your thyroid is underactive or overactive. One blood draw covers it, and it's reported as a single value. TSH is the standard first-line check of thyroid function, and an abnormal result often leads to follow-up tests such as free T4 (84439), which would appear as their own separate charges rather than part of this one.

When you'd see it

Common when symptoms like fatigue, weight change, or temperature sensitivity are being investigated, or to monitor thyroid medication. Often the only thyroid test needed unless the result is off.

Roughly what it costs

$15–$90 commonly billed

A ballpark on the billed amount. After insurance or a negotiated rate, what you owe is often far lower. Always compare against your Explanation of Benefits (EOB).

What's usually billed with it

The blood draw (36415) accompanies it, and it may appear with related thyroid tests like a free T4.

What to watch for

TSH is usually the starting thyroid test. If a whole panel of additional thyroid tests was billed alongside it, it's reasonable to ask whether all of them were ordered.

Specific things to question

• A full set of thyroid tests (free T4, free T3, antibodies) all billed at once when TSH alone was the order.
• Repeated TSH testing in a short window without a change in symptoms or medication.
• A blood-draw charge (36415) duplicated when the same stick supplied other tests too.

How to check this charge on your own bill

Find 84443 on your itemized bill and match it against your EOB. Confirm it appears only once, that any bundled services aren't also billed separately, and that the amount matches what your insurer says it allowed. If something doesn't line up, that's a fair question for the billing office.