C-peptide test cost in Chicago, IL — inpatient
In Chicago-Naperville-Elgin, IL-IN, 39 hospitals list a cash price for C-peptide blood test as an inpatient: from $18.25 to $489.90, with a median of $100.00. The lowest listed price is at Uchicago Medicine AdventHealth Bolingbrook and 3 other hospitals — $81.75 less than the median here. Across Illinois, the median is $103.60 at 99 hospitals.
Cash prices at 39 facilities across 28 cities for code 84681, as an inpatient (admitted to hospital) . Collected Sep 29, 2026; the hospital files themselves were last updated between Jan 1, 2025 and Apr 1, 2026.
Lowest$18.25Uchicago Medicine AdventHealth Bolingbrook + 3 more
Median$100.00half of hospitals charge less
Highest$489.90in this market
Difference26.8×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 Chicago-Naperville-Elgin, IL-IN.
median
Lowest $18.25Highest $489.90
Hospitals, cheapest first
| Hospital | Cash price | List price | Insurers pay | Off list |
|---|---|---|---|---|
| Uchicago Medicine AdventHealth Bolingbrook lowest Bolingbrook, IL · (630) 312-5000 HC ASSAY OF C-PEPTIDE - C-PEPTIDE+1 more line at this price File of Apr 1, 2026 · source file | $18.25 | $73.00 | — | 75% |
| Uchicago Medicine AdventHealth Hinsdale lowest Hinsdale, IL · (630) 856-9000 HC C PEPTIDE LEVEL - ARUP+1 more line at this price File of Apr 1, 2026 · source file | $18.25 | $73.00 | — | 75% |
| Uchicago Medicine AdventHealth La Grange lowest La Grange, IL · (708) 352-1200 HC C PEPTIDE LEVEL - ARUP+1 more line at this price File of Apr 1, 2026 · source file | $18.25 | $73.00 | — | 75% |
| Uchicago Medicine AdventHealth Glenoaks lowest Glendale Heights, IL · (630) 545-8000 HC ASSAY OF C-PEPTIDE - C-PEPTIDE+1 more line at this price File of Apr 1, 2026 · source file | $18.25 | $73.00 | — | 75% |
| Franciscan Health Munster Munster, IN · (219) 922-4200 C-Peptide File of Jan 1, 2026 · source file | $26.63 | $125.00 | $16.44–$109.00 | 79% |
| Louis A Weiss Memorial Hospital Chicago, IL · (773) 878-8700 C-Peptide, Serum SO File of Mar 17, 2025 · source file | $29.14 | $85.71 | $55.71 | 66% |
| Presence Saint Joseph Hospital - Chicago Chicago, IL · (773) 665-3000 HC C-PEPTIDE, SERUM File of Jan 1, 2026 · source file | $31.02 | $94.00 | $20.81–$87.18 | 67% |
| Uchicago Medicine AdventHealth Bolingbrook Bolingbrook, IL · (630) 312-5000 HC C PEPTIDE LEVEL - QWDL File of Apr 1, 2026 · source file | $32.50 | $130.00 | — | 75% |
| Uchicago Medicine AdventHealth Hinsdale Hinsdale, IL · (630) 856-9000 HC C PEPTIDE LEVEL - QWDL File of Apr 1, 2026 · source file | $32.50 | $130.00 | — | 75% |
| Uchicago Medicine AdventHealth La Grange La Grange, IL · (708) 352-1200 HC C PEPTIDE LEVEL - QWDL File of Apr 1, 2026 · source file | $32.50 | $130.00 | — | 75% |
| Uchicago Medicine AdventHealth Glenoaks Glendale Heights, IL · (630) 545-8000 HC C PEPTIDE LEVEL - QWDL File of Apr 1, 2026 · source file | $32.50 | $130.00 | — | 75% |
| Franciscan Health Rensselaer Rensselaer, IN · (219) 866-5141 C-Peptide File of Jan 1, 2026 · source file | $33.65 | $94.00 | $18.62–$93.65 | 64% |
| John H. Stroger, Jr. Hospital Chicago, IL · (312) 864-6000 RL-C-PEPTIDE File of Apr 1, 2026 · source file | $37.10 | $53.00 | $5.84–$42.40 | 30% |
| Franciscan Health Dyer Dyer, IN · (219) 865-2141 C-Peptide File of Jan 1, 2026 · source file | $52.11 | $193.00 | $18.62–$144.75 | 73% |
| Franciscan Health Crown Point Crown Point, IN · (219) 757-6100 C-Peptide File of Jan 1, 2026 · source file | $68.11 | $264.00 | $264.00 | 74% |
| Advocate Lutheran General Hospital Park Ridge, IL · (847) 723-2210 C-PEPTIDE File of Nov 4, 2025 · source file | $100.00 | $200.00 | $87.40–$160.00 | 50% |
| Advocate Childrens Hospital Oak Lawn Oak Lawn, IL C-PEPTIDE File of Nov 4, 2025 · source file | $100.00 | $200.00 | $87.40–$160.00 | 50% |
| Advocate Christ Medical Center Oak Lawn, IL · (708) 684-8000 C-PEPTIDE File of Nov 4, 2025 · source file | $100.00 | $200.00 | $87.40–$160.00 | 50% |
| Advocate Childrens Hospital Park Ridge Park Ridge, IL C-PEPTIDE File of Nov 4, 2025 · source file | $100.00 | $200.00 | $87.40–$160.00 | 50% |
| Advocate Trinity Hospital Chicago, IL · (773) 967-5002 C-PEPTIDE File of Nov 4, 2025 · source file | $100.00 | $200.00 | $87.40–$160.00 | 50% |
| Advocate Condell Medical Center Libertyville, IL · (847) 362-2900 C-PEPTIDE File of Nov 4, 2025 · source file | $100.00 | $200.00 | $87.40–$160.00 | 50% |
| Advocate Illinois Masonic Medical Center Chicago, IL · (773) 975-1600 C-PEPTIDE File of Nov 4, 2025 · source file | $100.00 | $200.00 | $87.40–$160.00 | 50% |
| Advocate South Suburban Hospital Hazel Crest, IL C-PEPTIDE File of Nov 4, 2025 · source file | $100.00 | $200.00 | $87.40–$160.00 | 50% |
| Advocate Sherman Hospital Elgin, IL · (847) 742-9800 C-PEPTIDE File of Nov 4, 2025 · source file | $100.00 | $200.00 | $87.40–$180.00 | 50% |
| Advocate Good Shepherd Hospital Barrington, IL · (847) 381-9600 C-PEPTIDE File of Nov 4, 2025 · source file | $100.00 | $200.00 | $87.40–$160.00 | 50% |
| Advocate Good Samaritan Hospital Downers Grove, IL · (630) 275-5900 C-PEPTIDE File of Nov 4, 2025 · source file | $100.00 | $200.00 | $87.40–$160.00 | 50% |
| Resilience Healthcare West Suburban Medical Center Oak Park, IL · (708) 383-6200 C-Peptide, Serum SO File of Mar 17, 2025 · source file | $110.27 | $324.32 | $210.81 | 66% |
| NorthShore University HealthSystems Glenbrook Hospital Glenview, IL R C-Peptide Urine File of Jan 1, 2025 · source file | $118.95 | $183.00 | $29.83–$97.91 | 35% |
| NorthShore University HealthSystems Skokie Hospital Skokie, IL R C-Peptide Urine File of Jan 1, 2025 · source file | $118.95 | $183.00 | $29.83–$97.91 | 35% |
| La Rabida Children's Hospital Chicago, IL · (773) 363-6700 C-PEPTIDE File of Apr 1, 2026 · source file | $134.50 | $134.50 | — | — |
| NorthShore University HealthSystems Skokie Hospital Skokie, IL R C-Peptide Lab+1 more line at this price File of Jan 1, 2025 · source file | $139.10 | $214.00 | $34.88–$114.49 | 35% |
| NorthShore University HealthSystems Glenbrook Hospital Glenview, IL R C-Peptide Lab+1 more line at this price File of Jan 1, 2025 · source file | $139.10 | $214.00 | $34.88–$114.49 | 35% |
| Endeavor Health Highland Park Hospital Highland Park, IL HB R C-PEPTIDE,URINE File of Apr 1, 2026 · source file | $183.00 | $183.00 | — | — |
| Northshore University Healthsystem - Evanston Hospital Evanston, IL · (847) 570-2000 HB R C-PEPTIDE,URINE File of Apr 1, 2026 · source file | $183.00 | $183.00 | — | — |
| Swedish Covenant Health Chicago, IL · (773) 878-8200 HB R C-PEPTIDE,URINE File of Apr 1, 2026 · source file | $183.00 | $183.00 | — | — |
| Northwest Community Hospital Arlington Heights, IL · (847) 618-1000 Hb Assay Of C-Peptide File of Apr 1, 2026 · source file | $202.00 | $202.00 | — | — |
| Swedish Covenant Health Chicago, IL · (773) 878-8200 HB C-PEPTIDE+1 more line at this price File of Apr 1, 2026 · source file | $214.00 | $214.00 | — | — |
| Northshore University Healthsystem - Evanston Hospital Evanston, IL · (847) 570-2000 HB R C-PEPTIDE LAB+1 more line at this price File of Apr 1, 2026 · source file | $214.00 | $214.00 | — | — |
| Endeavor Health Highland Park Hospital Highland Park, IL HB C-PEPTIDE+1 more line at this price File of Apr 1, 2026 · source file | $214.00 | $214.00 | — | — |
| Mercyhealth Hospital & Medical Center - Harvard Harvard, IL · (815) 943-5431 CHG ASSAY OF C-PEPTIDE File of Mar 1, 2026 · source file | $232.46 | $309.94 | — | 25% |
| Mercyhealth Crystal Lake Hospital & Medical Center Crystal Lake, IL · (792) 220-5500 CHG ASSAY OF C-PEPTIDE File of Mar 1, 2026 · source file | $237.32 | $316.42 | — | 25% |
| Uchicago Medicine Northwest Indiana Crown Point, IN · (312) 755-4706 HC C-PEPTIDE File of Apr 1, 2026 · source file | $246.00 | $246.00 | — | — |
| Ingalls Memorial Hospital Harvey, IL · (708) 333-2300 Hc C-Peptide File of Apr 1, 2026 · source file | $246.00 | $246.00 | — | — |
| Northwest Health - Porter Valparaiso, IN · (219) 983-8300 C Peptide- Send Out to CQ File of Apr 1, 2026 · source file | $286.92 | $797.00 | $191.28–$669.48 | 64% |
| Elmhurst Memorial Hospital Elmhurst, IL · (331) 221-1000 HC C - PEPTIDE File of Apr 1, 2026 · source file | $298.00 | $298.00 | — | — |
| Edward Hospital Naperville, IL · (630) 527-3000 HC C - PEPTIDE File of Apr 1, 2026 · source file | $298.00 | $298.00 | — | — |
| The University of Chicago Medical Center Chicago, IL · (773) 702-9785 Hc C-Peptide File of Apr 1, 2026 · source file | $404.00 | $404.00 | — | — |
| Jackson Park Hospital Foundation Chicago, IL · (773) 947-7500 C-PEPTIDE File of Dec 26, 2025 · source file | $489.90 | $612.37 | — | 20% |
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.
No cash discount This line's cash price equals the hospital's full list price. Many hospitals still reduce bills for uninsured patients: ask the billing office for its self-pay discount in writing. More
Inpatient: lowest $18.25, median $100.00, highest $489.90 — a 26.8× difference within the same market.
As an outpatient, the same code is billed by 61 facilities here, median $100.00 — that is the price to compare if you are not being admitted.
Cash or insurance?
At 20 of 22 hospitals that publish insurer rates for this code here, the cash price is below the highest rate a health plan has negotiated, and at 3 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 C-peptide test shows how much insulin the pancreas is making. It helps tell type 1 from type 2 diabetes and find the cause of low blood sugar.
What the price covers
The price usually covers running the test. The blood draw (36415) is often billed as a separate line.