An Explanation of Benefits (EOB) is not a bill — it is a statement your insurance company sends after processing a claim. Understanding every field helps you catch errors and know exactly how much you will actually receive.
What an EOB Is (and Is Not)
The EOB arrives by mail or in your online insurance portal within 2–4 weeks of claim submission. It shows how your insurer processed the claim but does not mean money has been sent yet. Reimbursement checks or direct deposits often follow separately.
Key Fields on an EOB
- Billed amount — What your therapist (or you, when self-submitting) charged. This is the face value on the superbill.
- Allowed amount — The maximum the plan will recognize for that service in your area. This is the UCR (Usual, Customary, and Reasonable) rate, and it may be lower than the billed amount.
- Deductible applied — How much of the allowed amount was applied toward your out-of-network deductible if it has not yet been met.
- Plan paid — The dollar amount the insurer actually reimbursed. For OON claims this is typically the plan's coinsurance percentage applied to the allowed amount, minus whatever went to deductible.
- Member responsibility — Your share: deductible + coinsurance + any amount above the allowed rate.
Why "Billed Amount" Differs From "Allowed Amount"
Your therapist might charge $200 for a 60-minute session, but your insurer's UCR rate for 90837 in your zip code might be $140. The plan calculates reimbursement on the $140 allowed amount, not the $200 billed amount. You are responsible for the $60 gap plus your coinsurance on the $140.
Common EOB Denial Codes
If the plan paid $0 or less than expected, look for the adjustment reason code:
- CO-4 — Incorrect modifier. The CPT code was billed with the wrong or missing modifier (e.g., missing telehealth modifier).
- CO-11 — Diagnosis code is not consistent with the procedure billed. Review the ICD-10 code on the superbill.
- CO-97 — The service is included in another code billed on the same date. Common with add-on codes.
- PR-1 — Deductible amount. The claim was applied to your deductible; no separate reimbursement is issued until it is met.
- CO-50 — Medical necessity not established. Contact your insurer to understand what documentation they need.
What to Do If the EOB Shows Less Than Expected
- Verify the allowed amount matches what you expected from your plan's fee schedule
- Check whether your OON deductible has been met for the year
- Confirm the CPT and ICD-10 codes on the submitted superbill are correct
- Call member services (number on your insurance card) and reference the claim number
- If the denial seems incorrect, file a formal appeal within the deadline shown on the EOB
Keeping Records
Save every EOB alongside the superbill it corresponds to. Cross-reference the date of service and CPT code to confirm the EOB reflects the right session. If you submit superbills monthly through a tool like Superbilled, organizing PDFs by month makes EOB reconciliation straightforward.