Medical billing mistakes are rampant, as we recently covered. One way to catch a mistake from a biller is to check the charges against your Health Insurance Explanation of Benefits (EOB).
An EOB is “the insurance company’s written explanation regarding a claim, showing what they paid and what the patient must pay,” according to HealthInsurance.org. It isn’t itself a bill, but it will detail what, exactly, you’re still on the hook to pay for out of pocket. Your insurance company is required to send you an EOB every time a file is claimed for your treatment.
This is useful when it comes to medical billing mistakes because you can check it against the bills your doctor or other health care provider sent you. You can see then if you were double-billed, for example, or charged for procedures or services you never received.

What to check on your explanation of benefits

There are a few different things to verify on your EOB when you receive it. HealthValues.org has a good explainer and example copy:

• 1. The first thing to check is that your doctor is listed correctly so you’re not overcharged if, say, the incorrectly-listed doctor is out-of-network, or was a specialist when you saw a generalist. “If you see multiple doctors, make sure the doctor listed on the EOB matches the date of service you actually saw that doctor,” writes HealthValues.org.
  2. Speaking of, make sure the date of service matches the date that you actually saw the doctor.
  3. Next, look at Charges. This is the total cost of your care. “The ‘Allowed Amount’ is what you actually have to pay after your preferred provider discount, if your claim is for an in­-network service,” writes HealthValues.org.
  4. But that doesn’t mean you’ll pay what’s listed in #3. The #4 section above details what you owe, broken up by co-pay, deductible, and co-insurance. In the above example, the patient was on the hook for $216.92 after the insurance discount. Then, the $43.76 figure is what’s left of the patient’s deductible.

That leaves $173.16 ($216.92-$43.76) after the deductible was hit. In this case, the patient’s co-insurance is 20 percent, so they will pay $34.63, which is 20 percent of that $173.16. So, coupled with the Deductible Payment, the patient owes $78.39.

Check for mistakes

One important thing to check on your EOB, CNBC reports, is that “the discounted rate for your in-network doctor or other provider should be the starting point for any coinsurance or deductible you are responsible for,” not the full charges as listed in #3 above.
So, in the above example, your deductible is applied after the in-network discount of $113.08 is applied to your total bill of $330. Then your co-insurance is applied.
If you do get a bill from your doctor’s office that charges you more than your EOB, “go by what the insurance company says,” writes CNBC.
Keep in mind, however, that your EOB itself can contain a mistake. Let’s say your physical should be 100 percent covered under your plan but you’re still charged for it. In that case, you’ll want to call your insurance company.