Appellate Case: 22-4082     Document: 010110963219   Date Filed: 12/05/2023   Page: 1
                                                                          FILED
                                                              United States Court of Appeals
                                     PUBLISH                          Tenth Circuit

                      UNITED STATES COURT OF APPEALS               December 5, 2023

                                                                 Christopher M. Wolpert
                             FOR THE TENTH CIRCUIT                   Clerk of Court


  IAN C.; A.C.,

         Plaintiffs - Appellants,

  v.                                                     No. 22-4082

  UNITEDHEALTHCARE
  INSURANCE COMPANY,

         Defendant - Appellee.

  ------------------------------

  CHAMBER OF COMMERCE OF THE
  UNITED STATES OF AMERICA,

         Amicus Curiae.


                   Appeal from the United States District Court
                             for the District of Utah
                         (D.C. No. 2:19-CV-00474-HCN)


 Brian Smith King of Brian S. King P.C., Salt Lake City, Utah, for Plaintiffs -
 Appellants.

 Amanda Shafer Berman of Crowell & Moring LLP, Washington, D.C. (Amy M.
 Pauli, Neil Nandi, and Samuel H. Ruddy of Crowell & Moring LLP,
 Washington, D.C., and Jennifer S. Romano of Crowell & Moring LLP, Los
 Angeles, California, with her on the brief) for Defendant - Appellee.

 Tara Morrissey, U.S. Chamber Litigation Center, Washington, D.C.; Meaghan
 VerGow, O’Melveny & Myers LLP, Washington, D.C., filed an amicus curiae
 brief on behalf of Defendant - Appellee, for the United States of America.
Appellate Case: 22-4082   Document: 010110963219      Date Filed: 12/05/2023   Page: 2



 Before BACHARACH, PHILLIPS, and EID, Circuit Judges.


 PHILLIPS, Circuit Judge.


       This appeal arises from an action under the Employee Retirement Income

 Security Act of 1974 (ERISA), 

–1461, to challenge the denial

 of healthcare benefits through an employer-sponsored plan. Ian C., the plan

 participant, claimed coverage for his son, A.C., the beneficiary, to receive care

 at an inpatient residential treatment center, Catalyst Residential Treatment, for

 mental-health and substance-abuse issues. The plan authorized

 UnitedHealthcare Insurance Company (United), the claims fiduciary, to

 determine A.C.’s eligibility for benefits under the plan. 1 After initially covering

 A.C.’s treatment at Catalyst, United later denied coverage.

       Ian C. internally appealed the adverse benefit determination, which

 United upheld on appeal. Ian C. then pursued his case against United in federal

 district court, where he alleged that United’s denial violated his right to receive

 a “full and fair review” of his claim under 

(2), 1104(a)(1). 2



       1
         United administered benefits for mental-health and substance-abuse
 services through its designee, United Behavioral Health. We refer to these
 entities collectively as “United.”
       2
         Ian C. and A.C. are both named plaintiffs on the complaint filed in the
 U.S. District Court for the District of Utah and are both named as appellants on
 the notice of appeal to this court. But for concision, we refer to the appellants
 collectively under the guise of “Ian C.,” as the covered plan participant and
 parent of the claimed beneficiary.
                                          2
Appellate Case: 22-4082   Document: 010110963219     Date Filed: 12/05/2023   Page: 3



 Ian C. argued that United arbitrarily and capriciously denied benefits to A.C.

 by failing to address A.C.’s substance abuse as an independent ground for

 coverage, by determining that A.C.’s continued treatment at Catalyst was not

 medically necessary, by ignoring the opinions of A.C.’s medical providers, and

 by misapplying the appropriate level-of-care guidelines. United denied these

 claims, and the parti