Free T4 test cost in Knoxville, TN
In Knoxville, TN, 6 hospitals list a cash price for Free T4 (free thyroxine) thyroid blood test: from $27.30 to $57.33, with a median of $30.03. The lowest listed price is at Parkwest Medical Center — $2.73 less than the median here. Across Tennessee, the median is $27.50 at 44 hospitals.
Cash prices at 6 facilities across 5 cities for code 84439, as an outpatient — the setting a self-pay patient normally buys. Collected Sep 23, 2026; the hospital files themselves were last updated between Aug 5, 2026 and Aug 27, 2026.
Where each hospital's price falls
Each dot is one hospital's cash price on a scale from the lowest to the highest in Knoxville, TN.
Hospitals, cheapest first
| Hospital | Cash price | List price | Insurers pay | Off list | File date |
|---|---|---|---|---|---|
| Parkwest Medical Center lowest Knoxville, TN THYROXINE FREE | $27.30 | $91.00 | $4.06–$81.90 | 70% | Aug 5, 2026 source file |
| Fort Sanders Regional Medical Center Knoxville, TN THYROXINE FREE | $30.03 | $91.00 | $4.06–$81.90 | 67% | Aug 5, 2026 source file |
| Methodist Medical Center of Oak Ridge Oak Ridge, TN THYROXINE FREE | $30.03 | $91.00 | $4.06–$81.90 | 67% | Aug 5, 2026 source file |
| Fort Loudoun Medical Center Lenoir City, TN THYROXINE FREE | $30.03 | $91.00 | $4.06–$81.90 | 67% | Aug 27, 2026 source file |
| Roane County Medical Center Harriman, TN THYROXINE FREE | $30.03 | $91.00 | $4.06–$81.90 | 67% | Aug 5, 2026 source file |
| Parkwest Medical Center Louisville, TN THYROXINE FREE | $57.33 | $91.00 | $8.10–$72.80 | 37% | Aug 5, 2026 source file |
Outpatient: lowest $27.30, median $30.03, highest $57.33 — a 2.1× difference within the same market.
Cash or insurance?
At 6 of 6 hospitals that publish insurer rates for this code here, the cash price is below the highest rate a health plan has negotiated, and at none is it below every plan's rate. If you have insurance but have not met your deductible, you usually pay your plan's negotiated rate, which falls somewhere in the "Insurers pay" column. Paying cash can cost less, but a cash payment usually does not count toward your deductible. Ask the hospital for both numbers before you book.
What it is
A free T4 test measures thyroxine that is not bound to proteins, the active form of the main thyroid hormone. It is usually ordered with or after a TSH test to check for an underactive or overactive thyroid and to adjust thyroid medicine.
What the price covers
The price usually covers the free T4 test only. The blood draw and the TSH test (84443) are billed separately.
2 rows held back from this comparison
They are priced below $1 or below a tenth of the national median for code 84439 ($60.00). Such a line is almost always a physician's fee billed separately, an assistant's share or a placeholder — a real charge, but not the price of the procedure itself.
| Parkwest Medical Center Louisville, TNTHYROXINE�FREE | $1.58 | file |
| Parkwest Medical Center Louisville, TNTHYROXINE FREE | $1.58 | file |