Magnesium test cost in San Jose, CA — inpatient
In San Jose-Sunnyvale-Santa Clara, CA, 4 hospitals list a cash price for magnesium blood test as an inpatient: from $4.72 to $189.00, with a median of $120.40. The lowest listed price is at Stanford Health Care — $115.68 less than the median here. Across California, the median is $106.08 at 103 hospitals.
Cash prices at 4 facilities across 4 cities for code 83735, as an inpatient (admitted to hospital) . Collected Sep 23, 2026; the hospital files themselves were last updated between Apr 1, 2026 and Apr 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 Jose-Sunnyvale-Santa Clara, CA.
Hospitals, cheapest first
| Hospital | Cash price | List price | Insurers pay | Off list | File date |
|---|---|---|---|---|---|
| Stanford Health Care lowest Stanford, CA · (650) 723-4000 HC 6956 Magnesium | $4.72 | $11.80 | — | 60% | Apr 1, 2026 source file |
| Stanford Health Care Stanford, CA · (650) 723-4000 HC 6956 12810r Magnesium | $7.61 | $19.03 | — | 60% | Apr 1, 2026 source file |
| Stanford Health Care Stanford, CA · (650) 723-4000 HC 6911 Magnesium RBC | $16.60 | $41.50 | — | 60% | Apr 1, 2026 source file |
| Kaiser Foundation Hospital - Santa Clara Santa Clara, CA · (408) 236-6400 ASSAY OF MAGNESIUM | $120.40 | $215.00 | $6.00–$20.00 | 44% | — source file |
| Kaiser Foundation Hospital - San Jose San Jose, CA · (408) 972-7000 ASSAY OF MAGNESIUM | $120.40 | $215.00 | $6.00–$20.00 | 44% | — source file |
| El Camino Hospital Mountain View, CA · (650) 940-7000 HC MAGNESIUM | $189.00 | $756.00 | — | 75% | Apr 1, 2026 source file |
| Stanford Health Care Stanford, CA · (650) 723-4000 HC Bmt I Magnesium | $254.80 | $637.00 | — | 60% | Apr 1, 2026 source file |
| Stanford Health Care Stanford, CA · (650) 723-4000 HC Magnesium Serum/Pl | $254.80 | $637.00 | — | 60% | Apr 1, 2026 source file |
| Stanford Health Care Stanford, CA · (650) 723-4000 HC Urine Magnesium | $254.80 | $637.00 | — | 60% | Apr 1, 2026 source file |
Inpatient: lowest $4.72, median $120.40, highest $189.00 — a 40.0× difference within the same market.
As an outpatient, the same code is billed by 5 facilities here, median $120.40 — that is the price to compare if you are not being admitted.
Cash or insurance?
At 0 of 2 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 magnesium test measures the level of magnesium in the blood. Doctors order it for muscle cramps or weakness, an irregular heartbeat, low potassium or calcium that does not correct, and for people on diuretics, long-term acid-reducing drugs or with kidney disease.
What the price covers
The price usually covers running the test. The blood draw (36415) is often billed as a separate line.