Free T4 test cost in St. Louis, MO — inpatient
In St. Louis, MO-IL, 8 hospitals list a cash price for Free T4 (free thyroxine) thyroid blood test as an inpatient: from $31.26 to $176.13, with a median of $115.20. The lowest listed price is at Mercy Rehabilitation Hospital South — $83.94 less than the median here. Across Missouri, the median is $87.90 at 30 hospitals.
Cash prices at 8 facilities across 8 cities for code 84439, as an inpatient (admitted to hospital) . Collected Sep 23, 2026; the hospital files themselves were last updated between Mar 16, 2026 and Apr 24, 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 St. Louis, MO-IL.
Hospitals, cheapest first
| Hospital | Cash price | List price | Insurers pay | Off list | File date |
|---|---|---|---|---|---|
| Mercy Rehabilitation Hospital South lowest Louis, MO THYROXINE FREE (FREE T4) | $31.26 | $31.26 | $31.26 | — | Mar 16, 2026 source file |
| Mercy Rehabilitation Hospital South lowest Louis, MO T4 FREE (THYROXINE) | $31.26 | $31.26 | $31.26 | — | Mar 16, 2026 source file |
| Mercy Rehabilitation Hospital South lowest Louis, MO THYROID FUNCTION PANEL | $31.26 | $31.26 | $31.26 | — | Mar 16, 2026 source file |
| American Healthcare Systems Illinois LLC Granite City, IL THYROXINE T4, FREE | $39.91 | $66.52 | $66.52 | 40% | — source file |
| Ranken Jordan Home for Convalescent Crippled Children Hospital Maryland Heights, MO T4, Free | $40.10 | $50.12 | — | 20% | Apr 24, 2026 source file |
| Ranken Jordan Home for Convalescent Crippled Children Hospital Maryland Heights, MO T4, Free, Direct Dialysis | $40.10 | $50.12 | — | 20% | Apr 24, 2026 source file |
| St Josephs Hospital Hospital Sisters Third Order of St Francis Breese, IL HC T4 FREE | $102.96 | $143.00 | $9.02–$143.00 | 28% | — source file |
| St Elizabeths Hospital of the Hospital Sisters of the Third Order of St Francis O'Fallon, IL HC T4 FREE | $127.44 | $177.00 | $9.02–$177.00 | 28% | — source file |
| St Josephs Hospital of the Hospital Sisters of the Third Order of St Francis Highland, IL HC T4 FREE | $136.80 | $190.00 | $18.04–$190.00 | 28% | — source file |
| Hshs Holy Family Hospital Inc Greenville, IL HC T4 FREE | $167.04 | $232.00 | $9.02–$232.00 | 28% | — source file |
| Mercy Rehabilitation Hospital St. Louis Chesterfield, MO THYROXINE FREE (FREE T4) | $176.13 | $176.13 | $176.13 | — | Mar 16, 2026 source file |
| Mercy Rehabilitation Hospital St. Louis Chesterfield, MO THYROID FUNCTION PANEL | $178.23 | $178.23 | $178.23 | — | Mar 16, 2026 source file |
| Mercy Rehabilitation Hospital St. Louis Chesterfield, MO T4 FREE (THYROXINE) | $178.23 | $178.23 | $178.23 | — | Mar 16, 2026 source file |
Inpatient: lowest $31.26, median $115.20, highest $176.13 — a 5.6× difference within the same market.
As an outpatient, the same code is billed by 12 facilities here, median $96.66 — that is the price to compare if you are not being admitted.
Cash or insurance?
At 5 of 7 hospitals that publish insurer rates for this code here, the cash price is below the highest rate a health plan has negotiated, and at 1 it is 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.