dissenting.
In reversing the district court, the majority decides an unargued and unpre-served issue. Contrary to the majority’s characterization of his argument, Moyer nowhere contends that the claim-denial letter violated 29 U.S.C. § 1133. Indeed, Moyer’s brief neither mentions the legal requirements for claim-denial letters nor *508cites § 1133 or its implementing regulation, 29 C.F.R. § 2560.503-1. In both the district court and on appeal, Moyer rested his argument on 29 U.S.C. § 1022 — the statute that governs summary plan descriptions — referring to the claim-denial letter only in passing. MetLife thus had no reason to respond to arguments under § 1133, and the district court never considered § 1133. The majority nevertheless interprets that statute to require claim-denial letters to include a warning setting forth the time limit for bringing a civil action under ERISA.
Ample authority counsels against the majority’s approach. “[W]e rely on the parties to frame the issues for decision and assign to courts the role of neutral arbiter of matters the parties present.” Greenlaw v. United States, 554 U.S. 237, 243, 128 S.Ct. 2559, 171 L.Ed.2d 399 (2008); accord Carducci v. Regan, 714 F.2d 171, 177 (D.C.Cir.1983) (Scalia, J.) (“The premise of our adversarial system is that appellate courts do not sit as self-directed boards of legal inquiry and research.... ”). And in the argument-forfeiture context, our precedent holds that “[ajrguments not squarely presented to the district court are not reviewed on appeal.” Thomas M. Cooley Law Sch. v. Kurzon Strauss, LLP, 759 F.3d 522, 528, 2014 WL 2959066, at *4 (6th Cir.2014); cf. United States v. Layne, 192 F.3d 556 (6th Cir.1999) (“[I]ssues adverted to in a perfunctory manner, unaccompanied by some effort at developed argumentation, are deemed waived....”). This rule “eases appellate review by having the district court first consider the issue [and] ensures fairness to litigants by preventing surprise issues from appearing on appeal.” Rice v. Jefferson Pilot Fin. Ins. Co., 578 F.3d 450, 454 (6th Cir.2009). These considerations apply with even greater force to arguments never raised by the parties.
Moreover, whether 29 C.F.R. § 2560.503-1 requires a claim-denial letter to state the limitations period for civil actions presents a more difficult issue than the majority acknowledges, buttressing my view that it errs in interpreting that regulation without the benefit of briefing. True, had Moyer argued that MetLife’s claim-denial letter violated § 1133, dicta in Engleson suggests that he would “have a colorable ERISA violation.” See Engleson v. Unum Life Ins. Co. of Am., 723 F.3d 611, 618 (6th Cir.2013). Yet, courts elsewhere split on whether the regulation requires a claim-denial letter to inform a plan participant of both their right to bring a civil action and the action’s limitations period. Compare Ortega Candelaria v. Orthobiologics LLC, 661 F.3d 675, 680 (1st Cir.2011) (holding that a claim-denial letter must include the limitations period for civil actions) and Novick v. Metro. Life Ins. Co., 764 F.Supp.2d 653, 660-64 (S.D.N.Y.2011) (same), with Heimeshoff v. Hartford Life & Accidental Ins. Co., No. 3:10cv1813 (JBA), 2012 WL 171325, at *6-7 (D.Conn. Jan. 20, 2012) (holding that a claim-denial letter complied with the regulation despite omitting the civil action limitations period) and Koblentz v. UPS Flexible Emp. Benefits Plan, No. 12-CV-0107-LAB, 2013 WL 4525432, at *4 & n. 5 (S.D.Cal. Aug. 23, 2013) (same).
The Fifth Circuit’s decision in McGowan v. New Orleans Employers International Longshoremen’s Ass’n, 538 Fed.Appx. 495 (5th Cir.2013), did not hold that a claim-denial letter must always include the time limit to bring an ERISA action. Rather, it held that the letter at issue there — which included the appropriate limitations period — “substantially complied” with § 1133 even though it failed to include the time limit for submitting an appeal to the plan administrator. Id. at 498. Likewise, the Fourth Circuit noted merely that “[t]he civil action is treated as an integral part of *509[a Ml and fair review]” before quoting the regulation. White v. Sun Life Assurance Co. of Canada, 488 F.3d 240, 247 n. 2 (4th Cir.2007). And that decision offered no opinion about the requirements of § 1133.
In its validating an unpreserved claim, the majority gives short shrift to the “substantial compliance” test that “[t]his circuit applies ... to determine whether § 1133’s notice requirements have been met.” Wenner v. Sun Life Assurance Co. of Canada, 482 F.3d 878, 882 (6th Cir.2007). Under our test, “[i]f the communications between the administrator and participant as a whole fulfill the twin purposes of § 1133, the administrator’s decision will be upheld even where the particular communication does not meet those requirements.” Id. (internal quotation marks omitted). The “twin purposes” of § 1133 are “(1) to notify the claimant of the specific reasons for a claim denial, and (2) to provide the claimant an opportunity to have that decision reviewed by the fiduciary” Id.; see also 29 U.S.C. § 1133.
Had Moyer presented an argument under § 1133, MetLife could have plausibly responded that its correspondence to Moyer, taken as a whole, fulfilled the purposes of § 1133 and substantially complied with its notice requirements despite omitting the limitations period. See McGowan, 538 Fed.Appx. at 498 (holding that pension fund substantially complied with ERISA despite failure to include time limit to submit request for review). But the majority deprives MetLife of this opportunity by taking up this issue and ruling in Moyer’s favor sua sponte, short-circuiting the adversarial process. All this precedes the majority’s issuance of a precedential decision on an issue unbriefed by either party.
I would decide the only issue briefed by Moyer and considered by the district court: whether MetLife’s failure to disclose the limitations period in the summary plan description violated § 1022 and 29 C.F.R. § 2520.102-2(b), thereby entitling Moyer to equitable tolling. On that issue, I would affirm the district court’s well-reasoned opinion,
I respectMly dissent.