Lab tests CPT 84100 Inpatient — admitted to hospital

Phosphorus test cost in Eau Claire, WI — inpatient

In Eau Claire, WI, 2 hospitals list a cash price for phosphorus (phosphate) blood test as an inpatient: from $41.60 to $46.55, with a median of $44.08. The lowest listed price is at Aspirus Stanley Hospital — $2.48 less than the median here. Across Wisconsin, the median is $41.60 at 97 hospitals.

Cash prices at 2 facilities across 2 cities for code 84100, as an inpatient (admitted to hospital) . Collected Sep 27, 2026; the hospital files themselves were last updated between Feb 20, 2026 and Apr 1, 2026.

Lowest$41.60Aspirus Stanley Hospital

Median$44.08half of hospitals charge less

Highest$46.55in this market

Difference1.1×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 Eau Claire, WI.

median

Lowest $41.60Highest $46.55

Hospitals, cheapest first

Hospital	Cash price	List price	Insurers pay	Off list
Aspirus Stanley Hospital lowest Stanley, WI · (715) 644-5571 Fac Assay of Phosphorus File of Apr 1, 2026 · source file	$41.60	$64.00	—	35%
Marshfield Medical Center - Eau Claire Eau Claire, WI · (715) 858-8100 PHOSPHORUS ASSAY-TECH File of Feb 20, 2026 · source file	$46.55	$49.00	$26.95–$47.53	5%

Hospital The hospital that published the price, its city and the line exactly as written in its price file.

Cash price The hospital's own price for a patient paying without insurance (“discounted cash” in its price file). Hospitals must publish it under federal law, 45 CFR 180.50. Call to confirm it before booking. More

List price The hospital's full chargemaster price (“gross charge”) before any discount. Almost nobody pays it; the gap to the cash price shows what the self-pay discount is worth. More

Insurers pay The lowest and highest rates this hospital has agreed with insurance plans for the same item, from its price file. If the cash price is below what your plan pays and you have not met your deductible, paying cash can cost you less. More

Off list How much lower the cash price is than the list price.

Inpatient: lowest $41.60, median $44.08, highest $46.55 — a 1.1× difference within the same market.

As an outpatient, the same code is billed by 3 facilities here, median $41.60 — that is the price to compare if you are not being admitted.

Cash or insurance?

At the one hospital here that publishes insurer rates for this code, the cash price is below the highest rate a health plan has negotiated. 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 phosphorus test measures phosphate in the blood. It is used with calcium for kidney disease, bone disease and parathyroid problems.

What the price covers

The price usually covers running the test. The blood draw (36415) is often billed as a separate line.