The deductible, copay and coinsurance on my EOB do not equal what it says I owe. Why?

On one line of the Explanation of Benefits: deductible $10, copay $5, coinsurance $5, not covered $0. And then, on the same line, patient responsibility $50.

Those numbers describe the same thing twice and disagree. Both come from your plan, which makes this the one problem on this list that the billing office cannot fix.

What the columns mean

• Deductible — the part applied to the amount you pay before coverage starts
• Copay — a flat amount for the visit type
• Coinsurance — your percentage share after the deductible
• Not covered — an amount the plan excludes
• Patient responsibility — what the plan says you owe in total

The first four are the components. The last is supposed to be their sum. When it is not, something in the adjudication has not been explained on the document.

Ordinary reasons it happens

• An out-of-pocket maximum was applied partway through, capping your share
• A penalty was added — for missing prior authorisation, or for going out of network — that has its own column the EOB did not print
• Coordination with a second plan took place and only the net appears
• A rounding or display convention the form does not explain
• The summary covers more lines than are shown

Several of these are perfectly correct and simply undocumented on the page you were sent.

Why it still matters

Because the provider bills from the patient-responsibility figure. If that figure is wrong, the bill inherits the error — and everyone downstream is working from a number nobody can reconstruct.

Who to call

Your plan, not the provider. The number is on your insurance card.

Please explain how [patient responsibility] was calculated for [service] when the cost-share amounts on the same Explanation of Benefits total [sum]. Please send me a corrected Explanation of Benefits if you cannot reconcile it.

Ask for the reprocessed EOB

If the plan agrees something is wrong, they reprocess the claim and issue a corrected EOB. That document is what you then send the provider, and it is what makes the corrected bill follow.

Ask for the reference number of the call, and ask how long reprocessing takes. It is usually a few weeks, and the bill will keep arriving in the meantime — ask the provider to hold the account while the plan reprocesses.

Do not pay the difference to make it go away

If the components are right and the total is wrong, paying the total means paying money nobody has justified. The plan is required to explain its own adjudication; asking it to is not an imposition.

This is general information, not legal, medical or financial advice, and not a statement about your particular bill. A difference between two documents often has an ordinary explanation, and the billing office is the one who can give it.

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