What is an Explanation of Benefits (EOB)? A Breakdown of the Breakdown
Your EOB explains the cost-share for services you receive on Medicare
Reviewed by: Michael Howard, Licensed Insurance Agent. Written by: Aaron Garcia.
Explanation of Benefits (EOB) go to enrollees in Medicare AdvantageMedicare Advantage is health insurance for Americans aged 65 and older that blends Medicare benefits with private health insurance. This typically includes a bundle of Original Medicare (Parts A and B) and Medicare Prescription Drug Plan (Part D). and Medicare Prescription Drug Plan (Part D)Medicare Prescription Drug Plan (Part D) is prescription drug coverage for people enrolled in Medicare. Part D is optional and is offered by private insurance companies.
EOBs show the claims and charges applied to your policy the previous month
EOBs offer detailed breakdowns of the costs, including the full price of services, amounts covered by your policy, and what you owe
Your EOBs will also reflect copaymentA copayment (copay) is the fixed amount you pay directly to your provider for medical services or prescription drugs covered in your plan. For example: If your plan includes a copayment of $20 for office visits, you'll pay $20 to your doctor whenever you have an appointment. and coinsuranceCoinsurance is the percentage of your medical costs that you pay after you meet your deductible. The remaining amount is paid by your insurance company. For example: If you have a $1,000 medical bill and your coinsurance is 20%, you'll pay $200. Your insurance company will cover the final $800. payments you’ve made and how much you pay toward your deductiblesA deductible is the amount you pay out of pocket before your insurance company covers its portion of your medical bills. For example: If your deductible is $1,000, your insurance company will not cover any costs until you pay the first $1,000 yourself.
An EOB is NOT a bill
The first thing to know about an Explanation of Benefits is that it’s not a bill. Instead, it’s a summary of the claims and charges applied to your policy from the previous month.
For example, let’s say you had to visit several doctors and specialists in June because of an injury. The EOB you receive in July will reflect the claims and charges from those visits. Your EOB will show what your insurance company has agreed to pay for the services you received. With your EOB, you can check that you’re being charged correctly by your doctors and specialists when you get your bills.
Anyone enrolled in Medicare Advantage and Medicare Prescription Drug Plan (Part D) will receive an EOB when they use their policy. You don’t need to request an EOB — you automatically receive an EOB the month after a claim, whether it’s from an office visit or a prescription.
Each plan has its own EOB form; private insurance companies provide Medicare Advantage and Part D, and your EOB will come directly from them. If your MA plan and Part D plan are from different companies, you’ll receive an EOB for each.
You can expect to see a few standard terms, no matter who sends your Explanation of Benefits. They are:
- Billed Amount: what your doctor would charge for the service if you did not have insurance. Sometimes called Total Charges
- Allowed Amount: how much your insurance company has agreed to pay your doctor for the service you received
- Benefit Amount: how much your insurance company will pay for your service
- Adjusted Amount: the amount you saved by having insurance
- Copayment: the fixed amount you pay directly to your provider for medical services or prescription drugs covered in your plan
- Coinsurance: the percentage of your medical costs that you pay after you meet your deductible; your insurance company pays the remaining amount
- Deductible: the amount you pay out of pocket before your insurance company covers its portion of your medical bills
If you misplaced your most recent EOB or didn’t receive it in the mail, contact your insurance company. A representative should be able to provide the information you need and verify your mailing address. Many companies also offer paperless options; if you have an internet connection, you may be able to view your EOB online at any time.
No, but you’ll receive a Medicare Summary Notice (MSN), the Medicare explanation of benefits. Like the EOB, the MSN is not a bill — it’s a monthly snapshot of the services you’ve needed and what Medicare has agreed to pay for them. You can think of these as your monthly Medicare statements.
Does my EOB show specific prescription info?
If you have a Medicare Prescription Drug EOB, it can show which medicines you’re taking, how much they cost, and how much your insurance covers. 
Will I get an EOB each month if I don't see a doctor?
Your insurance company is only required to send you an EOB when you make a claim. This happens any time you see a healthcare provider through your insurance. If you didn’t see your doctor, you probably won’t get an EOB. If you do receive one but haven’t seen a doctor (or filled a prescription) lately, make sure to check it for errors — this can be a helpful tool in spotting fraud on your account.