How each check works
MedBillCheckup runs 19 fixed checks. They are fixed rules written as code, not an AI model, so the same figures give the same answer every time. A flag is a question to ask the billing office, not a verdict on a charge. Only your provider or insurer can say what is right.
Updated October 30, 2026
Some checks need a few optional answers from you. Without those, they do not run.
Does the bill add up?
Line total
- It compares
- Quantity times unit price against the line’s total, with a cent per unit allowed for rounding.
- Public data
- None outside your bill.
- Why it can be normal
- A line may include a fee or tax the statement does not show separately.
Lines against the total
- It compares
- The lines added together against the subtotal or total billed.
- Public data
- None outside your bill.
- Why it can be normal
- A discount, a page we could not read, or a charge shown elsewhere can explain a gap. The check stays quiet when a page looks unread or a line has no amount.
Amount due
- It compares
- Amount due against patient responsibility minus payments already made.
- Public data
- None outside your bill.
- Why it can be normal
- An earlier balance, a late fee or a payment the statement does not show.
Insurance and your share
- It compares
- Total billed against insurance paid, adjustments, discounts and what you owe, added up. Small rounding gaps are ignored.
- Public data
- None outside your bill.
- Why it can be normal
- A statement that leaves out the insurance payment or the adjustment can look short. The check says when that may be the reason.
Your share
- It compares
- Patient responsibility against the deductible, coinsurance and copay added together, when the bill shows at least two of them. Also against the per-line patient amounts, when every line has one.
- Public data
- None outside your bill.
- Why it can be normal
- Services your plan does not cover are part of what you owe but are not in those three.
Adjustments and credits
- It compares
- Adjustments larger than the charge or the total billed, a negative amount you owe, and negative lines with no adjustment label.
- Public data
- None outside your bill.
- Why it can be normal
- A credit from an earlier statement, a refund owed to you, or a layout we read differently.
Repeats and quantities
A charge that repeats
- It compares
- Pairs of lines with nearly the same description and the same amount (or no amount on either), on the same day or when one of them has no day.
- Public data
- None outside your bill.
- Why it can be normal
- Two blood draws or two doses on one day can be correct. If you remember it happening once, ask.
A billing code that repeats
- It compares
- Lines that carry the same billing code.
- Public data
- None outside your bill.
- Why it can be normal
- Daily charges, doses and several units use the same code on purpose. When each repeat falls on its own day, or the words suggest a repeat, it is shown as information only.
A quantity worth confirming
- It compares
- Lines with a quantity above one for visits and scans usually given once (an office visit, an X-ray, a scan, an admission). Any quantity of ten or more is shown as information.
- Public data
- None outside your bill.
- Why it can be normal
- A longer stay or a larger dose.
Similar charges from two providers
- It compares
- Lines from different billing organizations with a similar description on the same day, or when a date is missing.
- Public data
- None outside your bill.
- Why it can be normal
- In the US a facility and a doctor often both bill for one service. See what is a facility fee.
Dates and missing information
Dates
- It compares
- Dates against each other and against today. Flags: a due date before the statement date, a statement or service date in the future, a service after the statement date, a service period that ends before it starts, dates more than a year apart, and a date we could not read.
- Public data
- None outside your bill.
- Why it can be normal
- A typo, a statement that combines visits, or a charge from another visit.
Missing information
- It compares
- Whether the statement shows itemized charges, dates of service, billing codes (US), the provider, a total, and, when an insurer is mentioned, the insurance and patient amounts. On a US bill that names no insurer, it also checks whether the bill went to insurance.
- Public data
- None outside your bill.
- Why it can be normal
- Many summary statements leave these out. You can ask for them: see the itemized bill letter.
Prices and quantities against public figures
Routine supplies billed alone
- It compares
- Lines for everyday supplies or overhead (gloves, tissues, gowns, linens, toiletries, cups, a room supply, an overhead, administrative or cleaning fee). Surgical and sterile supplies are left alone.
- Public data
- None outside your bill.
- Why it can be normal
- Many facilities fold these into the room or facility charge. Whether they bill them apart depends on their policy and, if you have coverage, on your plan.
Everyday medicine price
- It compares
- Seven everyday items: acetaminophen, ibuprofen, aspirin, antacid, diphenhydramine, stool softener, saline flush. A flag when one is over $20 a tablet, dose or capsule ($60 for a syringe). Injectables, prescription combinations and lab tests are skipped. On a US bill, for a few common strengths of four of these (acetaminophen, ibuprofen, aspirin, diphenhydramine), it also names what pharmacies paid on average.
- Public data
- Medicaid NADAC, from CMS, effective October 21, 2026. On a US facility bill the check also asks about the list of standard charges, which hospitals must publish (45 CFR 180.50).
- Why it can be normal
- Hospitals set their own prices, and handling and giving the dose are part of them. The check asks what the charge includes. It does not say what the price should be.
Units Medicare usually expects
- It compares
- US only. Units of a drug, supply, equipment or ambulance code, added up per day or per line, against the most units Medicare expects from one provider. Medicare has tables for doctors’ offices, hospital outpatient care and home medical equipment suppliers; only a count above all of them is flagged.
- Public data
- CMS Medically Unlikely Edits, tables effective October 1, 2026.
- Why it can be normal
- A larger dose, units for several days added on one line, or a supplier’s delivery covering several weeks.
Money you may get back or may not owe (from your optional answers)
Paid more than your share
- It compares
- What you say you paid against your share from your EOB or the bill. A gap of a dollar or more is shown.
- Needs
- What you paid.
- Public data
- None outside your documents.
- Why it can be normal
- The account may already show a credit, or a payment may still be posting.
Yearly out-of-pocket maximum
- It compares
- Your plan’s maximum and what has counted toward it, against your share of this bill.
- Needs
- Your plan’s yearly maximum and what has counted toward it. US only.
- Public data
- None outside your answers.
- Why it can be normal
- Out-of-network or non-covered care, and care in a new plan year, can count differently.
Possible surprise bill
- It compares
- Whether it was emergency care, or care from someone you did not choose at an in-network hospital or surgery center, and whether the bill or EOB says out-of-network.
- Needs
- Your answers on the kind of care and on network status. US only.
- Public data
- The No Surprises Act, as CMS describes it.
- Why it can be normal
- The Act covers most private health plans. Other programs have their own protections. Only your plan or provider can say whether it applied.
Bill above your EOB amount
- It compares
- The amount you typed from your EOB against what the bill asks. A bill a dollar or more higher is flagged.
- Needs
- The amount from your EOB. US only.
- Public data
- Your own EOB.
- Why it can be normal
- The bill may be sent before the insurer paid, a second insurer may not have paid, or the bill may include another visit.
No check says what a service should cost. Where a public figure is used, it is named and dated.
For the steps from reading your bill to the full list, see how it works.
The official data we check against
HCPCS Level II code listVersion in use: effective October 1, 2026
Centers for Medicare & Medicaid Services (CMS). Medicare’s names for drug, supply, equipment and ambulance codes. Updated by Medicare every quarter.
Medicare Claims Processing Manual, chapter 17
Centers for Medicare & Medicaid Services (CMS). How drug units are counted: in multiples of the amount in the code’s name, rounded up.
Medically Unlikely EditsVersion in use: effective October 1, 2026
Centers for Medicare & Medicaid Services (CMS). The most units of a drug, supply or equipment code Medicare usually expects for one patient from one provider, on one day or on one line of a bill. Home medical equipment suppliers have their own limits, which can cover several weeks of supplies. Not every code has one. Updated by Medicare every quarter.
National Average Drug Acquisition Cost (NADAC)Version in use: effective October 21, 2026
Centers for Medicare & Medicaid Services (CMS). What pharmacies paid on average for acetaminophen 325 mg and 500 mg tablets, ibuprofen 200 mg tablets, aspirin 325 mg tablets and diphenhydramine 25 mg capsules. A pharmacy purchase cost, not a retail price.
Centers for Medicare & Medicaid Services (CMS). Surprise out-of-network bills, and Good Faith Estimates for people paying without insurance.
We never show the official descriptions of five-digit procedure codes (CPT). They belong to the American Medical Association.