Denial Code 100: Payment Made to Patient (Simple Explanation)
In medical billing, Denial Code 100 is a very common denial. This denial means:
✅ The insurance company processed the claim and sent the payment directly to the patient (Patient/Insured/Responsible Party) instead of paying the provider.
Why Does Denial Code 100 Happen?
This denial mainly happens for two reasons:
1) AOB Not Signed (Assignment of Benefits)
If the Assignment of Benefits (AOB) form is not signed by the patient, the insurance company may not have the legal authorization to pay the provider.
So, they pay the patient directly.
2) Provider is Out-of-Network
If the provider is out-of-network, and the patient’s insurance plan includes out-of-network benefits, then the insurance may issue the payment to the patient (not the provider).
On-Call / Insurance Verification Flow (What to Ask)
When you contact insurance for this denial, follow this simple flow:
Step 1: Confirm Claim Paid to Patient
First confirm:
“Was the claim payment made to the patient?”
Step 2: Ask for Processed & Paid Date
Ask:
“What is the processed date and paid date?”
This confirms exactly when the payment was released.
Step 3: Get Financial Details
Ask for these three important amounts:
- Allowed Amount (AA)
- Paid Amount (PA)
- Patient Responsibility (PTR)
(Coinsurance / Deductible / Copayment)
Step 4: Verify Calculation
Now do this quick check:
✅ Paid Amount (PA) + Patient Responsibility (PTR) = Allowed Amount (AA)
If the total does not match, then:
- Probe the insurance representative
- Ask them to recheck and provide correct figures
Step 5: Confirm Why Claim Was Paid to Patient
Ask:
“Why was the claim paid to the patient and not the provider?”
This helps you identify AOB issue or OON plan rules.
Step 6: Ask for Reference Details
Always collect:
- Claim Number
- Call Reference Number
This is mandatory for documentation and escalation.
Important Notes & Required Actions
Here are key action points every billing team must follow:
✅ 1) If Paid to Patient → Bill Patient Directly
Since the payment went to the patient:
👉 The provider can bill the patient directly.
❌ 2) Do Not Bill Secondary / Next Payer
This denial is not for secondary billing.
✅ It is the patient’s responsibility.
✅ 3) No Need to Ask for Check Details
Since payment was not made to the provider:
- Provider cannot track the check
- No check number / EFT trace needed
So:
👉 Do not waste time asking check details
Conclusion
Denial Code 100 is not a true rejection — it simply means insurance has already paid, but paid the wrong party (patient instead of provider) due to:
- Unsigned AOB
- Out-of-network payment rules
The correct action is:
✅ Verify claim details → document → bill patient.
