Free T4 test cost in San Diego, CA
In San Diego-Chula Vista-Carlsbad, CA, 11 hospitals list a cash price for Free T4 (free thyroxine) thyroid blood test: from $9.00 to $114.26, with a median of $24.03. The lowest listed price is at Paradise Valley Hospital — $15.03 less than the median here. Across California, the median is $68.12 at 104 hospitals.
Cash prices at 11 facilities across 7 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 Apr 1, 2026 and Sep 1, 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 San Diego-Chula Vista-Carlsbad, CA.
Hospitals, cheapest first
| Hospital | Cash price | List price | Insurers pay | Off list | File date |
|---|---|---|---|---|---|
| Paradise Valley Hospital lowest National City, CA THYROXINE FREE | $9.00 | $122.43 | $9.02–$160.00 | 93% | Sep 1, 2026 source file |
| Paradise Valley Hospital lowest National City, CA FREE T4 DIALYSIS LC | $9.00 | $160.00 | $9.02–$160.00 | 94% | Sep 1, 2026 source file |
| UC San Diego Medical Center San Diego, CA Thyroxine (thyroid chemical) measurement | $13.20 | $24.00 | $2.88–$32.40 | 45% | Apr 1, 2026 source file |
| Sharp Memorial Hospital San Diego, CA HC FREE THYROXIN EQUILIB DIA | $24.03 | $32.04 | $1.10–$95.09 | 25% | — source file |
| Sharp Coronado Hospital and Healthcare Center Coronado, CA HC FREE THYROXIN EQUILIB DIA | $24.03 | $32.04 | $1.00–$24.67 | 25% | — source file |
| Sharp Chula Vista Medical Center Chula Vista, CA HC FREE THYROXIN EQUILIB DIA | $24.03 | $32.04 | $1.00–$25.63 | 25% | — source file |
| Grossmont Hospital Corporation La Mesa, CA HC FREE THYROXIN EQUILIB DIA | $24.03 | $32.04 | $1.00–$28.84 | 25% | — source file |
| Rady Children's Hospital - San Diego San Diego, CA Rch Scrmer Hc-Free T4 Eia | $60.00 | $80.00 | — | 25% | Apr 1, 2026 source file |
| Rady Children's Hospital - San Diego San Diego, CA Rch Scren-Free T4 Eia | $60.00 | $80.00 | — | 25% | Apr 1, 2026 source file |
| Rady Children's Hospital - San Diego San Diego, CA Rch Scrlj-Free T4 Eia | $60.00 | $80.00 | — | 25% | Apr 1, 2026 source file |
| Rady Children's Hospital - San Diego San Diego, CA Rsp Thyroxine Free | $60.00 | $80.00 | — | 25% | Apr 1, 2026 source file |
| Rady Children's Hospital - San Diego San Diego, CA Rch Free Thyroxine | $60.00 | $80.00 | — | 25% | Apr 1, 2026 source file |
| Rady Children's Hospital - San Diego San Diego, CA Rsp Thyroxine Free 301 | $60.00 | $80.00 | — | 25% | Apr 1, 2026 source file |
| Rady Children's Hospital - San Diego San Diego, CA Scripps Nicu-Free T4 Eia | $60.00 | $80.00 | — | 25% | Apr 1, 2026 source file |
| Rady Children's Hospital - San Diego San Diego, CA Rch Scrmer Cv-Free T4 Eia | $60.00 | $80.00 | — | 25% | Apr 1, 2026 source file |
| Kaiser Foundation Hospital - San Marcos San Marcos, CA ASSAY OF FREE THYROXINE | $68.12 | $131.00 | $7.00–$20.00 | 48% | — source file |
| Kaiser Foundation Hospital - San Diego - Clairemont Mesa San Diego, CA ASSAY OF FREE THYROXINE | $68.12 | $131.00 | $7.00–$20.00 | 48% | — source file |
| Kaiser Foundation Hospital - San Diego - Zion San Diego, CA ASSAY OF FREE THYROXINE | $68.12 | $131.00 | $7.00–$20.00 | 48% | — source file |
| Sharp Coronado Hospital and Healthcare Center Coronado, CA HC ASSAY OF FREE THYROXINE - T4 FREE | $90.75 | $121.00 | $1.15–$96.80 | 25% | — source file |
| Sharp Memorial Hospital San Diego, CA HC ASSAY OF FREE THYROXINE - T4 FREE | $90.75 | $121.00 | $1.00–$725.00 | 25% | — source file |
| Sharp Chula Vista Medical Center Chula Vista, CA HC ASSAY OF FREE THYROXINE - T4 FREE | $90.75 | $121.00 | $1.00–$4,366.00 | 25% | — source file |
| Grossmont Hospital Corporation La Mesa, CA HC ASSAY OF FREE THYROXINE - T4 FREE | $90.75 | $121.00 | $1.15–$118.58 | 25% | — source file |
| UC San Diego Medical Center San Diego, CA Thyroxine (Thyroid Chemical) Measurement | $99.00 | $180.00 | $9.02–$243.00 | 45% | Apr 1, 2026 source file |
| Rady Children's Hospital - San Diego San Diego, CA Rch Lab-Free T4 (Thyroxine) | $105.75 | $141.00 | — | 25% | Apr 1, 2026 source file |
| Tri-City Medical Center Oceanside, CA Free T4 Level | $114.26 | $190.44 | $7.89–$150.26 | 40% | May 29, 2026 source file |
Outpatient: lowest $9.00, median $24.03, highest $114.26 — a 12.7× difference within the same market.
As an inpatient, the same code is billed by 10 facilities here, median $42.02. Inpatient and outpatient prices are not comparable and are kept on separate pages: the inpatient charge covers admission, not the same purchase.
Cash or insurance?
At 7 of 10 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.
1 row held back from this comparison
It is 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.
| Tri-City Medical Center Oceanside, CAThyroxine (T4) Free, Direct, S LC | $2.48 | file |