How long does UnitedHealthcare / Optum have to respond to a Level-1 appeal?

UnitedHealthcare / Optum has 30 calendar days to respond to a Level-1 appeal. If the internal appeal is denied, you have 60 days from that denial to request external review by an Independent Review Organization (IRO). Federal rules under ERISA and your state's prompt-payment statute may impose shorter windows — verify before filing.

How do I submit an appeal to UnitedHealthcare / Optum?

The fastest route is UnitedHealthcare / Optum's online provider portal. You can also fax appeals to 1-801-938-2100. Written appeals may be mailed to: UnitedHealthcare Appeals, P.O. Box 30432, Salt Lake City, UT 84130. Use certified mail with return receipt for any paper submission to create a timestamped record.

What are the most common UnitedHealthcare / Optum denial codes for behavioral health?

The most common UnitedHealthcare / Optum denial codes for behavioral health practices are: CO-97, CO-4, CO-50, CO-167, PR-96. Each has a dedicated appeal guide on AppealWin with the denial explanation, MHPAEA arguments, and a direct link to generate your appeal letter.

What should I include in a UnitedHealthcare / Optum behavioral health appeal letter?

A strong UnitedHealthcare / Optum appeal should include: (1) the specific CARC or RARC denial code and the reason for dispute; (2) clinical documentation supporting medical necessity; (3) a MHPAEA parity argument if the denial applies stricter criteria to mental health than to comparable medical services; (4) a written request for UnitedHealthcare / Optum's NQTL comparative analysis under CAA 2021 § 203; and (5) your NPI, patient member ID, claim number, and date of service. AppealWin generates a complete, MHPAEA-grounded letter from your denial code in under 60 seconds.

UnitedHealthcare / Optum Insurance Appeal Guide

A complete reference for behavioral health therapists appealing a UnitedHealthcare / Optum denial. Every common CARC code, the correct appeal address, MHPAEA parity arguments, and response deadlines — all in one place.

UnitedHealthcare / Optum appeal details

Appeal Address

UnitedHealthcare Appeals
P.O. Box 30432
Salt Lake City, UT 84130

Level-1 Response Window

30 calendar days

External Review Deadline

60 days from Level-1 denial

Fax

1-801-938-2100

Provider Portal

File online

UnitedHealthcare / Optum MHPAEA Parity Notes

UHC/Optum manages behavioral health in-house for most commercial products. UHC was subject to a landmark MHPAEA lawsuit (Wit v. United Behavioral Health, 2021 remanded 2022). Document medical necessity criteria carefully; UHC has been found to use overly restrictive internal coverage criteria.

Most common UnitedHealthcare / Optum denial codes

CO-97

Bundled / Already Adjudicated

The payer says this service is included in another service that's already been billed and …

CO-4

Modifier Inconsistent with Procedure

The payer says the modifier you used does not match the procedure code you billed. The mos…

CO-50MHPAEA

Not Medically Necessary

The payer is saying the service was not medically necessary under their criteria. In behav…

CO-167MHPAEA

Diagnosis Not Covered

The payer is saying the diagnosis code you submitted is not covered under the patient's pl…

All UnitedHealthcare / Optum denial code appeal guides

Select a code to see the denial explanation, appeal strategy, MHPAEA arguments, and a direct link to generate your appeal letter.

Code	Denial reason	Group	MHPAEA	Guide
CO-4common	Modifier Inconsistent with Procedure	CO	—	Appeal guide →
CO-11	Diagnosis Inconsistent with Procedure	CO	—	Appeal guide →
CO-15	Authorization Number Missing or Invalid	CO	—	Appeal guide →
CO-16	Missing or Incomplete Information	CO	—	Appeal guide →
CO-18	Duplicate Claim	CO	—	Appeal guide →
CO-22	Coordination of Benefits	CO	—	Appeal guide →
CO-29	Timely Filing Limit Expired	CO	—	Appeal guide →
CO-45	Charge Exceeds Fee Schedule	CO	—	Appeal guide →
CO-50common	Not Medically Necessary	CO	Yes	Appeal guide →
CO-96	Non-Covered Charges	CO	—	Appeal guide →
CO-97common	Bundled / Already Adjudicated	CO	—	Appeal guide →
CO-119	Benefit Maximum Reached	CO	Yes	Appeal guide →
CO-167common	Diagnosis Not Covered	CO	Yes	Appeal guide →
CO-197	Precertification / Authorization Absent	CO	Yes	Appeal guide →
OA-23	Prior Authorization Required / Other Payer	OA	Yes	Appeal guide →

Frequently asked questions — UnitedHealthcare / Optum appeals

How long does UnitedHealthcare / Optum have to respond to a Level-1 appeal?: UnitedHealthcare / Optum has 30 calendar days to respond to a Level-1 appeal. If the internal appeal is denied, you have 60 days from that denial to request external review by an Independent Review Organization (IRO). Your state's prompt-payment statute may impose a shorter window — verify before filing.
How do I submit an appeal to UnitedHealthcare / Optum?: The fastest route is the UnitedHealthcare / Optum provider portal. You can also fax appeals to 1-801-938-2100. Written appeals may be mailed to: UnitedHealthcare Appeals, P.O. Box 30432, Salt Lake City, UT 84130. Use certified mail with return receipt for any paper submission.
What is UnitedHealthcare / Optum's MHPAEA mental-health parity posture?: UHC/Optum manages behavioral health in-house for most commercial products. UHC was subject to a landmark MHPAEA lawsuit (Wit v. United Behavioral Health, 2021 remanded 2022). Document medical necessity criteria carefully; UHC has been found to use overly restrictive internal coverage criteria.
What are the most common UnitedHealthcare / Optum denial codes for behavioral health?: The most common UnitedHealthcare / Optum denial codes for behavioral health practices are: CO-97, CO-4, CO-50, CO-167, PR-96. Select any code in the table above for the denial explanation, appeal strategy, and MHPAEA arguments.
What should I include in a UnitedHealthcare / Optum behavioral health appeal letter?: A strong appeal should include: (1) the specific CARC or RARC denial code and reason for dispute; (2) clinical documentation supporting medical necessity; (3) a MHPAEA parity argument if the denial applies stricter criteria to mental health than to comparable medical services; (4) a written request for UnitedHealthcare / Optum's NQTL comparative analysis under CAA 2021 § 203; and (5) your NPI, patient member ID, claim number, and date of service. AppealWin generates a complete, MHPAEA-grounded letter from your denial code in under 60 seconds.

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State-specific appeal rights

State prompt-payment windows and parity laws can strengthen your UnitedHealthcare / Optum appeal. Select your state to see applicable statutes.

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