Lab tests CPT 83735 Inpatient — admitted to hospital

Magnesium test cost in Vallejo, CA — inpatient

In Vallejo, CA, 3 hospitals list a cash price for magnesium blood test as an inpatient: from $120.40 to $292.00, with a median of $120.40. The lowest listed price is at Kaiser Foundation Hospital & Rehab Center - Vallejo and 1 other hospital. Across California, the median is $106.08 at 103 hospitals.

Cash prices at 3 facilities across 3 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.

Lowest$120.40Kaiser Foundation Hospital & Rehab Center - Vallejo + 1 more
Median$120.40half pay less
Highest$292.00in this market
Difference2.4×highest vs lowest

Where each hospital's price falls

Each dot is one hospital's cash price on a scale from the lowest to the highest in Vallejo, CA.

median
Lowest $120.40Highest $292.00

Hospitals, cheapest first

HospitalCash price List priceInsurers payOff listFile date
Kaiser Foundation Hospital & Rehab Center - Vallejo lowest Vallejo, CA · (707) 651-1000 ASSAY OF MAGNESIUM $120.40 $215.00 $6.00–$20.00 44% —
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Kaiser Foundation Hospital - Vacaville lowest Vacaville, CA · (707) 624-4000 ASSAY OF MAGNESIUM $120.40 $215.00 $6.00–$20.00 44% —
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NorthBay Medical Center Fairfield, CA · (707) 646-5000 Magnesium $292.00 $292.00 — — Apr 1, 2026
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NorthBay Medical Center Fairfield, CA · (707) 646-5000 Magnesium Level 24 Hour Urine $292.00 $292.00 — — Apr 1, 2026
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NorthBay Medical Center Fairfield, CA · (707) 646-5000 Magnesium Level 24 Hour Urine $292.00 $292.00 — — Apr 1, 2026
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NorthBay Medical Center Fairfield, CA · (707) 646-5000 Magnesium $292.00 $292.00 — — Apr 1, 2026
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NorthBay Medical Center Fairfield, CA · (707) 646-5000 Magnesium Level Urine $292.00 $292.00 — — Apr 1, 2026
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NorthBay Medical Center Fairfield, CA · (707) 646-5000 Magnesium Level Urine $292.00 $292.00 — — Apr 1, 2026
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Inpatient: lowest $120.40, median $120.40, highest $292.00 — a 2.4× difference within the same market.

As an outpatient, the same code is billed by 3 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.