CMS Price Transparency Data

Blood test, magnesium

Facility: Northwestern Lake Forest Hospital

Billing Code: 83735 (CPT)

Factual Cost Summary (Answer Capsule)

CPT Billing Code: 83735
Insurance Median: $58
Cash Discount Price: $81
vs. Medicare Baseline: 8.66x Medicare

The contracted insurance negotiated median rate for a Blood test, magnesium at Northwestern Lake Forest Hospital is $58. If you are paying out-of-pocket or uninsured, the self-pay cash discount rate is $81. Compared to the federal Medicare reimbursement reference rate of $6.7, this hospital’s rate is 8.66x the Medicare baseline. Located in 1000 N Westmoreland Road, Lake Forest, IL.

Cash / Self-Pay

$81

Average discount available for prompt cash payment at this facility.

Insurance Median

$58

Median negotiated contract rate across all mapped commercial carriers.

Medicare Reference Rate

$6.7

Standard federal government reimbursement rate for this code.

Visual Cost Comparison vs. Medicare

Medicare Reference Baseline: $6.7 (100%)

Cash / Self-Pay: $81 (1209%)

Insurance Median: $58 (866%)

Cash: $81 (1209% of Medicare)

Ins. Median: $58 (866% of Medicare)

Understanding this gauge: We use the federal Medicare rate of $6.7 as the cost baseline. Rates below the baseline represent excellent value. In-network commercial rates commonly hover around 150% - 250% of Medicare, while rates exceeding 300% are elevated. Hover over the green and blue markers to view detailed calculations.

Elevated Commercial Rate Alert (Value-Gap)

The negotiated rate at this facility is 866% of the Medicare baseline (a markup of 766%). Patients with high-deductible plans or out-of-network benefits may face excessive out-of-pocket costs.

Consult Patient Advocate

Out-of-Pocket Cost Estimator

Estimate whether it is more economical to use your insurance or pay the upfront self-pay cash rate.

Billing Status

Remaining Deductible ($)

Your Coinsurance Rate (%)

Input your details and click calculate to compare out-of-pocket costs.

Commercial Insurance Negotiated Rates

Negotiated contract ranges established by major commercial carriers at this facility.

Carrier / Plan Group	Contract Rate Range	vs. Medicare Reference
Aetna	$19 - $53	284%
Blue Cross Blue Shield	$25 - $116	373%
Healthlink [125]	$58	866%
Health'S Finest Network [126]	$74 - $104	1104%
Beechstreet [176]	$93	1388%
Multiplan/Phcs [142]	$93 - $116	1388%
First Health Plan [6034]	$95	1418%
UnitedHealthcare	$116	1731%

Self-Pay Upfront Cash Action Plan

Request a "Self-Pay classification" with the billing desk before receiving care.
Ask for a written "Prompt-Pay Discount" agreement quoting the price of $81.
Request and sign a "Waiver of Insurance Submission" to prevent automatic billing.
Verify CPT Code matches exactly: 83735.

Insurance In-Network Protection Plan

Contact your insurance company to confirm Northwestern Lake Forest Hospital is fully in-network.
Ask your insurer if "Prior Authorization" is required for CPT code 83735.
Confirm the specific physician or imaging center is also in-network (not just the hospital building).
Audit your Explanation of Benefits (EOB) against the final itemized hospital invoice.