Bill vs EOB

What Is an EOB (Explanation of Benefits)?

An Explanation of Benefits is a statement from your insurer that breaks down how a claim was processed.

Updated August 16, 2026 · 6 min read

Quick answer

An EOB is a statement your health insurer sends after processing a medical claim. It shows the total charge, what insurance paid, any discounts or adjustments, and your remaining responsibility. An EOB is not a bill.

Why You Receive an EOB

Federal law requires health insurers to send an EOB every time a claim is processed under your plan. Whether the claim is paid in full, partially paid, or denied, you receive a statement explaining what happened.

Key Sections of an EOB

Every EOB follows a similar structure with several key fields: the date of service, the provider who billed, service codes (CPT or HCPCS), the billed amount, the allowed amount, what insurance paid, and your patient responsibility.

  • Date of Service - the date you received care.
  • Provider - the doctor, hospital, or lab that billed.
  • Service Codes - CPT or HCPCS codes describing what was done.
  • Billed Amount - what the provider charged.
  • Allowed Amount - what your plan says the service should cost.
  • Insurance Paid - what your insurer actually paid the provider.
  • Patient Responsibility - your share: copay, coinsurance, deductible.

What the Numbers Mean Together

The billed amount and the allowed amount are rarely the same. If you went in-network, the provider agreed to accept the allowed amount as payment in full and the difference disappears as a contractual adjustment. If you went out-of-network, the provider may bill you for the gap.

Why the EOB Matters

Your EOB is the source document for verifying that a bill is correct. When a provider sends you a statement, every line on that bill should correspond to a line on your EOB. If the numbers do not match, the EOB gives you the evidence you need to dispute the bill.

What the research says

Health insurers must send an EOB for every covered claim under federal law.

U.S. Department of Health and Human Services · Source

Frequently asked questions

Is an EOB the same as a medical bill?

No. An EOB is a breakdown of how your insurer processed a claim. A medical bill is a separate document from your provider asking you to pay a specific amount.

What if I never received an EOB?

Contact your insurer and request one. Under federal law, your plan must provide an EOB for every processed claim.

Can I use an EOB to dispute a bill?

Yes. The EOB shows exactly what your plan approved, what was paid, and what you owe. If the provider bill differs from the EOB, you can use it as evidence.

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