How to read a medical bill — and fight the ones that are wrong

The envelope has a way of arriving on a Friday. A number that makes no sense, a wall of codes, and a due date designed to make you reach for the checkbook before you understand what you're paying for. Millions of seniors pay these bills as-is — out of fear, out of habit, or just to make the envelope stop coming.

Here's the thing the billing system counts on you not knowing: a meaningful share of medical bills contain errors, and the process for challenging them is a right, not a favor. This guide is the calm, ordered version of what a professional does when a bill lands.

A medical bill is one party's opinion of what you owe. The document that actually matters is the statement from Medicare or your plan — the Medicare Summary Notice for Original Medicare, or the Explanation of Benefits for Medicare Advantage. It shows what the provider billed, what Medicare approved, what was paid, and what you can legitimately be charged.

If a bill and the insurance statement disagree, first confirm that they cover the same services and dates. Ask the billing office to explain the difference and whether any claim or other insurance payment is still pending. Medicare says providers who accept assignment usually wait for Medicare to pay its share before requesting yours. That is not a guarantee that every bill can be ignored until processing finishes; ask how the due date will be handled during review.

1. 1.Duplicate charges — the same service billed twice, sometimes with slightly different wording. Compare line items against each other, not just against the total.
2. 2.Services that never happened — a test that was ordered then cancelled, a supply that never appeared. If you don't remember it, question it.
3. 3.A service description or code you do not understand. Ask the billing office for an itemized explanation rather than assuming a different-sounding description proves an error.
4. 4.Balance billing — being charged the difference between what a provider wanted and what Medicare approved. Providers who accept Medicare assignment generally can't do this.
5. 5.Bills sent before insurance processed — the full sticker price, mailed while the claim is still pending. These often melt to a fraction once processing finishes.

1. 1.Match the bill against your Medicare statement line by line. Highlight anything that appears on one but not the other.
2. 2.Call the provider's billing office. Name the discrepancy specifically. Ask them to hold the account while it's reviewed — most will.
3. 3.If Medicare denied something you believe is covered, file an appeal. For Original Medicare, the first level is a redetermination and the window is 120 days after getting the MSN. Medicare Advantage and Part D have different appeal rules; follow the notice for your coverage.
4. 4.Put disagreements in writing. Phone promises evaporate; letters and portal messages create a record.
5. 5.Ask the billing office how it will handle the account while reviewing your question. A dispute or appeal does not by itself guarantee a collection hold. Request written confirmation of any arrangement and keep copies of everything.

Appeals are not a long shot. A large share of Medicare appeals succeed, especially for straightforward coding and coverage errors — most people simply never file. The system quietly profits from exhaustion.

A Navigate Care advocate does all of the above as a matter of routine — reading every bill, catching what's wrong, filing what needs filing. Families are consistently surprised by the same discovery: the scariest number in the envelope was never the real one.