Magnesium test cost in Seattle, WA
In Seattle-Tacoma-Bellevue, WA, 15 hospitals list a cash price for magnesium blood test: from $14.06 to $100.40, with a median of $48.48. The lowest listed price is at Overlake Medical Center & Clinics — $34.42 less than the median here. Across Washington, the median is $49.20 at 33 hospitals.
Cash prices at 15 facilities across 12 cities for code 83735, as an outpatient — the setting a self-pay patient normally buys. Collected Sep 23, 2026; the hospital files themselves were last updated between Feb 28, 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 Seattle-Tacoma-Bellevue, WA.
Hospitals, cheapest first
| Hospital | Cash price | List price | Insurers pay | Off list | File date |
|---|---|---|---|---|---|
| Overlake Medical Center & Clinics lowest Bellevue, WA · (425) 688-5000 Hc Magnesium, U | $14.06 | $28.13 | — | 50% | Apr 1, 2026 source file |
| Virginia Mason Medical Center Seattle, WA · (206) 223-6600 MAGNESIUM | $35.19 | $69.00 | $41.40–$55.20 | 49% | — source file |
| Saint Clare Hospital Lakewood, WA · (253) 588-1711 HC MAGNESIUM SERUM | $40.14 | $139.23 | $6.70–$104.43 | 71% | Feb 28, 2026 source file |
| Overlake Medical Center & Clinics Bellevue, WA · (425) 688-5000 Hc Assay Of Magnesium | $42.00 | $84.00 | — | 50% | Apr 1, 2026 source file |
| St Anthony Hospital Gig Harbor, WA · (253) 530-2050 HC MAGNESIUM SERUM | $42.35 | $139.23 | $6.70–$104.43 | 70% | Feb 28, 2026 source file |
| Highline Medical Center Burien, WA · (206) 431-5237 HC MAGNESIUM SERUM | $42.52 | $139.23 | $6.70–$125.31 | 69% | Feb 28, 2026 source file |
| St Francis Community Hospital Federal Way, WA · (253) 944-8100 HC MAGNESIUM SERUM | $43.70 | $139.23 | $6.70–$104.43 | 69% | Feb 28, 2026 source file |
| St Joseph Medical Center Tacoma, WA · (253) 627-4101 HC MAGNESIUM SERUM | $46.12 | $139.23 | $6.70–$104.43 | 67% | Feb 28, 2026 source file |
| Swedish Issaquah Issaquah, WA · (425) 313-4000 HC MAGNESIUM QUANT URINE | $48.48 | $101.00 | — | 52% | Apr 1, 2026 source file |
| Swedish Issaquah Issaquah, WA · (425) 313-4000 HC ASSAY OF MAGNESIUM LAB | $48.48 | $101.00 | — | 52% | Apr 1, 2026 source file |
| Swedish Issaquah Issaquah, WA · (425) 313-4000 HC ASSAY OF MAGNESIUM CDM | $48.48 | $101.00 | — | 52% | Apr 1, 2026 source file |
| Swedish Medical Center / Cherry Hill Seattle, WA · (206) 320-2000 HC MAGNESIUM QUANT URINE | $48.48 | $101.00 | — | 52% | Apr 1, 2026 source file |
| Swedish Medical Center / Cherry Hill Seattle, WA · (206) 320-2000 HC ASSAY OF MAGNESIUM LAB | $48.48 | $101.00 | — | 52% | Apr 1, 2026 source file |
| Swedish Medical Center / Cherry Hill Seattle, WA · (206) 320-2000 HC ASSAY OF MAGNESIUM CDM | $48.48 | $101.00 | — | 52% | Apr 1, 2026 source file |
| Swedish Medical Center / Cherry Hill Seattle, WA · (206) 320-2000 HC MAGNESIUM QUANT URINE | $48.48 | $101.00 | — | 52% | Apr 1, 2026 source file |
| Swedish Medical Center / Cherry Hill Seattle, WA · (206) 320-2000 HC ASSAY OF MAGNESIUM LAB | $48.48 | $101.00 | — | 52% | Apr 1, 2026 source file |
| Swedish Medical Center / Cherry Hill Seattle, WA · (206) 320-2000 HC ASSAY OF MAGNESIUM CDM | $48.48 | $101.00 | — | 52% | Apr 1, 2026 source file |
| Swedish Edmonds Edmonds, WA · (425) 640-4000 HC ASSAY OF MAGNESIUM LAB | $48.48 | $101.00 | — | 52% | Apr 1, 2026 source file |
| Swedish Edmonds Edmonds, WA · (425) 640-4000 HC ASSAY OF MAGNESIUM CDM | $48.48 | $101.00 | — | 52% | Apr 1, 2026 source file |
| Swedish Edmonds Edmonds, WA · (425) 640-4000 HC MAGNESIUM QUANT URINE | $48.48 | $101.00 | — | 52% | Apr 1, 2026 source file |
| Enumclaw Regional Hospital Association Enumclaw, WA HC MAGNESIUM SERUM | $49.20 | $139.23 | $6.70–$125.31 | 65% | Feb 28, 2026 source file |
| Providence Regional Medical Center Everett Everett, WA · (425) 261-2000 HC ASSAY OF MAGNESIUM CDM | $52.52 | $101.00 | — | 48% | Apr 1, 2026 source file |
| Providence Regional Medical Center Everett Everett, WA · (425) 261-2000 HC ASSAY OF MAGNESIUM LAB | $52.52 | $101.00 | — | 48% | Apr 1, 2026 source file |
| Overlake Medical Center & Clinics Bellevue, WA · (425) 688-5000 Hc Magnesium, Rbc | $52.81 | $105.62 | — | 50% | Apr 1, 2026 source file |
| Cascade Valley Hospital Arlington, WA · (360) 435-2133 HC ASSAY OF MAGNESIUM | $63.20 | $79.00 | $6.70–$71.10 | 20% | — source file |
| Kaiser Permanente Central Hospital Seattle, WA · (206) 326-3000 MAGNESIUM | $76.00 | $95.00 | $6.00–$20.00 | 20% | Apr 1, 2026 source file |
| Seattle Children's Hospital Seattle, WA · (206) 987-2000 Magnesium, Body Fluid | $100.40 | $100.40 | $25.30–$96.38 | — | — source file |
| Seattle Children's Hospital Seattle, WA · (206) 987-2000 UR Stone Risk Magnesium | $100.40 | $100.40 | $25.30–$96.38 | — | — source file |
| Seattle Children's Hospital Seattle, WA · (206) 987-2000 Magnesium Red Blood Cell | $102.90 | $102.90 | $25.93–$98.78 | — | — source file |
Outpatient: lowest $14.06, median $48.48, highest $100.40 — a 7.1× difference within the same market.
As an inpatient, the same code is billed by 15 facilities here, median $48.48. 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 8 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 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.