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CO-106 Denial Code: Patient Payment Option Not in Effect

CO-106 means the patient's chosen payment option or benefit election was not in effect when the service was provided. The payer could not apply the option the claim relied on, so the service was denied or processed differently.

Code: CO-106 (CARC 106)
Status: Active In use since January 1, 1995.
Code set: Claim Adjustment Reason Codes (CARC)
Group codes: CO (Contractual Obligation): The payer holds the provider responsible, often because eligibility or election status should have been verified. The amount generally cannot be billed to the patient under CO.
PR (Patient Responsibility): The patient is responsible because the election gap was theirs, for example an option they did not complete or renew. Check plan terms before billing.
Official description: Patient payment option/election not in effect.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What CO-106 means

CARC 106 reads patient payment option/election not in effect. Some coverage lets the patient choose among options: a benefit tier, a program, an enrollment election, or a particular way their benefits are paid. When the claim depends on an option that was not active on the date of service, the payer reports CARC 106.

The patient may still have coverage. The problem is that the specific election did not exist, had not started, or had ended when the service took place.

Because the code is general, the payer’s remark codes and a call to provider services are usually needed to learn which election was involved.

Common causes

The patient selected a new plan option that had not taken effect on the date of service.
An election required annual renewal and was not renewed.
The patient’s paperwork for the option was incomplete, so the payer never activated it.
The claim was billed under an option the patient never chose, such as the wrong product or program.
A retroactive change moved the patient off the option after the service was provided.

How to fix it

Run a fresh eligibility check for the date of service and note exactly which plan option was active.
Call the payer if the eligibility response does not explain the denial. Ask which election was missing and its effective dates.
Ask the patient whether they enrolled in, changed, or dropped an option. They may need to contact their plan or employer to correct it.
If the election is corrected retroactively, resubmit the claim. If the claim carried the wrong plan or product information, send a corrected claim with resubmission code 7 in box 22.
If the election was not in effect, bill the coverage that was active, or bill the patient if the group is PR and your financial policy allows.

How to prevent it

Verify eligibility, including the specific plan option, before every visit rather than only at the first visit.
Re-verify around plan-year changes and open enrollment periods, when elections change most often.
Record the plan option and effective dates in the patient account.
Our guide to eligibility and COB denials covers a front-desk verification workflow that catches election gaps early.

PR-27 (Expenses incurred after coverage terminated.): Expenses incurred after coverage ended, a broader coverage lapse.
CO-200 (Expenses incurred during lapse in coverage): Expenses incurred during a lapse in coverage.
CO-177 (Patient has not met the required eligibility requirements.): Patient did not meet the required eligibility requirements.
CO-31 (Patient cannot be identified as our insured.): Patient cannot be identified as the payer's insured at all.

CO-106 FAQ

What is a patient payment option or election?

A choice the patient makes within their coverage, such as a benefit option, plan tier, or program election, that changes how claims are paid. The code says that choice was not active on the date of service.

Can I resubmit after a CO-106?

Yes, if the election is later confirmed as active for that date or corrected retroactively. Otherwise bill the correct coverage or follow the group code for patient responsibility.

Is CO-106 an eligibility denial?

It is closely related. The patient may be covered, but not under the option the claim assumed.

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