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CO-61 Denial Code: No Second Surgical Opinion Obtained

CO-61 means the payer adjusted or denied payment because the plan required a second surgical opinion before the procedure and none was obtained or documented. The requirement comes from the patient's plan; check whether it truly applied and whether an opinion exists.

Quick facts

Code
CO-61 (CARC 61)
Status
Active In use since January 1, 1995; last modified March 1, 2017.
Code set
Claim Adjustment Reason Codes (CARC)
Group codes
  • CO (Contractual Obligation): The provider absorbs the adjustment and can't bill the patient on this basis.
  • PR (Patient Responsibility): Some plans put the penalty on the member for not following plan procedures. The patient may be billed if the plan reports PR.
Official description
Adjusted for failure to obtain second surgical opinion
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What CO-61 means

CARC 61 says adjusted for failure to obtain second surgical opinion. Some health plans require members to get an independent second opinion before certain elective surgeries. If the plan’s records show no second opinion before the surgery date, it reduces or denies payment and reports CO-61.

Second opinion requirements were more common in older plan designs. Today they tend to appear in specific employer or union plans and in some workers’ compensation programs. Whether the penalty is assigned to the provider (CO) or the member (PR) depends on the plan’s rules.

Common causes

  • Plan requires a second opinion for the procedure and none was obtained.
  • Second opinion obtained but not reported to the payer or not recorded in its system.
  • Opinion from a non-qualifying provider, such as a surgeon in the same group when the plan requires an independent one.
  • Authorization process missed the requirement, because staff didn’t check plan-specific rules.

How to fix it

  1. Confirm the requirement in the plan documents or with the payer, including which procedures it applies to.
  2. Check for an existing second opinion in the patient’s records or from the referring provider.
  3. If an opinion exists, send it to the payer and request reprocessing or appeal.
  4. If the surgery was urgent, appeal with documentation that the requirement shouldn’t apply.
  5. If no opinion exists and the requirement applies, determine whether the plan allows a retroactive review; otherwise write off (CO) or bill the patient (PR) according to the group code.

How to prevent it

  • Review plan-specific surgical requirements during authorization.
  • Ask referring providers whether a second opinion was already obtained.
  • Schedule second opinions early so surgery dates aren’t delayed.
  • Document the opinion and submit it with the authorization request. See authorization and referral denials.

Specialty notes

Orthopedic and spine surgery practices see second opinion requirements most often, particularly in workers’ compensation cases. State workers’ compensation rules may define who can provide the opinion and when it must happen.

Remark codes that may appear with CO-61

  • N130 (Consult plan benefit documents/guidelines for information about restrictions for this service.): Points to plan documents describing the second opinion requirement.
  • CO-95 (Plan procedures not followed.): Plan procedures weren't followed, a general version of this denial.
  • CO-197 (Precertification/authorization/notification/pre-treatment absent.): Precertification or authorization absent.
  • CO-39 (Services denied at the time authorization/pre-certification was requested.): Authorization requested and denied.
  • CO-272 (Coverage/program guidelines were not met.): Coverage or program guidelines weren't met.

CO-61 FAQ

Do many plans require second surgical opinions?

Fewer than in the past, but some employer plans, union plans, and workers' compensation programs still require them for certain elective surgeries. The requirement is in the plan documents or authorization rules.

What if a second opinion was obtained?

Send the payer the second opinion documentation, including the consulting surgeon, date, and findings, and ask for reprocessing or file an appeal.

Does the requirement apply to emergencies?

Second opinion requirements typically apply to elective, non-emergency surgery. If the procedure was urgent, document that and appeal.

Is CO-61 only applied to surgeons?

It usually appears on the surgeon's claim, but some plans also reduce related facility or anesthesia claims for the same procedure. Review every claim tied to the surgery date.

Who should get the second opinion?

Usually the patient arranges it, often with help from the surgeon's office. Plans may require the opinion to come from an independent, qualified surgeon, sometimes from a list the plan provides.