Why do I owe this, if I have insurance?
Deductible, copay, coinsurance, EOB, patient responsibility. What each one means, why the bill arrived anyway, and what to do if it looks wrong.
Five words that decide what you owe
Nearly every confusing medical bill comes down to these. They are not complicated once separated from each other.
Deductible
The amount you pay yourself before insurance starts paying.If your deductible is $2,000, you pay the first $2,000 of covered care in the plan year. It resets, usually in January, which is why bills in the early part of the year are often larger.
Copay
A flat fee per visit, set by your plan.A $30 copay is $30 whether the visit cost the practice $80 or $400. You usually pay it at the desk, so it rarely appears on a later bill.
Coinsurance
What is coinsurance? A percentage of the cost, paid after the deductible is met.With 20% coinsurance on a $1,000 procedure, insurance pays $800 and you owe $200. This is the one that surprises people most, because the amount depends on the price of the care rather than being a fixed fee.
Out-of-pocket maximum
The ceiling on what you pay in a plan year.Once your deductible, copays, and coinsurance add up to this figure, covered care is paid in full for the rest of the year. Premiums do not count toward it.
Patient responsibility
What is patient responsibility? The total of everything above that is yours to pay.This is the number on your bill. It is what is left after the insurer has processed the claim and paid its share.
Deductible vs coinsurance
These get confused constantly, and they apply at different stages. The deductible comes first and is a fixed amount you clear. Coinsurance comes after and is a percentage that keeps applying until you hit your out-of-pocket maximum.
| Deductible | Coinsurance | |
|---|---|---|
| What it is | A fixed amount | A percentage of the cost |
| When it applies | Before insurance pays anything | After the deductible is met |
| Does it change per visit | No, you draw it down until cleared | Yes, it scales with the price of the care |
| Example | $2,000 deductible: you pay the first $2,000 | 20% coinsurance on $1,000: you pay $200 |
What is an EOB, and why is it not a bill?
Explanation of Benefits
Comes from your insurer. It is a summary of how a claim was processed: what the provider billed, what your plan allowed, what it paid, and what is left with you.
Do not pay from this. It is not a request for money.
The bill
Comes from your provider, after the insurer has paid its share. The amount should match the patient-responsibility figure on the EOB for that claim.
If the two do not match, ask before paying.
Why the bill rarely matches the estimate
An estimate is produced before the care happens and before the insurer has processed anything. Two things then move: what was actually done during the visit, and what your plan decides to allow and pay. Neither is knowable in advance with precision, which is why estimates and final bills so often differ.
Under the No Surprises Act, if you are uninsured or paying yourself, you can ask for a Good Faith Estimate before scheduled care. If the final bill comes in at least $400 above it, there is a formal dispute process.
This is why Patriot Pay engages after the claim has been adjudicated rather than predicting what you might owe beforehand. By that point the number is settled rather than forecast, and the explanation of how it was reached is the real one.
Medical bill dispute: what to do if the bill looks wrong
Querying a bill is ordinary and providers expect it. Work through these in order before paying.
If you need more time to pay, see medical bill payment plans.
Common questions
General information about how medical billing works, not financial, legal, or medical advice. Plan terms vary.
Every question on this page is one your staff answers by phone
“Why do I owe this?” is the single most common billing call, and it is the reason balances sit unpaid rather than disputed. Patriot Pay’s AI billing agents answer it directly, in plain language and in over 100 languages, at the moment the patient is looking at the balance. Anything they cannot resolve reaches your team with the full conversation attached.