OPINION OF THE COURT

FISHER, Circuit Judge.

This appeal arises out of the 2008 death of Frederick Viera ("Viera") in a head-on motorcycle accident. At the time of his death, Viera was covered under an employer-provided accidental death and dismemberment policy ("Policy"), issued by Life Insurance Company of America ("LINA"), and subject to the Employee Retirement Income Security Act ("ERISA"), 29 U.S.C. §§ 1101 et seq. Viera's wife and the executrix of his estate, Hetty Viera ("Plaintiff"), submitted a claim under the Policy following his death. LINA denied Plaintiff's claim, both initially and on appeal. Subsequently, Plaintiff filed suit, but the United States District Court for the Eastern District of Pennsylvania found for LINA on cross-motions for summary judgment. It concluded that the Policy gave LINA discretionary authority to determine eligibility. It therefore reviewed LINA's decision under a deferential abuse-of-discretion standard and held that LINA was entitled to summary judgment. We conclude that deferential review was not appropriate, given the language of the Policy, and thus remand for further proceedings.

I.

A. Factual History

On October 14, 2008, Viera was seriously injured in a motorcycle accident in Grand Junction, Colorado. He was treated at St. Mary's Hospital and Medical Center ("St. Mary's") for approximately three hours and subsequently died.

On the date of his death, Viera maintained the Policy, an employer-provided accidental death and dismemberment policy regulated under ERISA.1 The Policy was issued and administered by LINA.

Viera had a pre-existing chronic condition known as atrial fibrillation, which was diagnosed prior to LINA's issuing the Policy. As part of the medical treatment for this condition, Viera received medication called Coumadin (also known as Warfarin). Coumadin is a prescription oral anticoagulant drug prescribed for the prevention and treatment of blood clots.

Following Viera's motorcycle accident, doctors at St. Mary's made several findings regarding his treatment and death. For example, the Final Assessment made in the Emergency Report confirmed that Viera was "on Coumadin with therapeutic INR2 significantly complicating trauma management." (App. at 160.) The Discharge Summary prepared by Dr. Michael Bradshaw of St. Mary's described Viera's death as caused by "multiple injuries in a head-on motorcycle versus car accident with severe pelvic fractures, lower extremity fractures, and a fully coumadinized patient due to atrial fibrillation." (Id. at 138.)

The Certificate of Death confirmed that the immediate cause of Viera's death was "multiple injuries," and it ambiguously noted that "arteriosclerotic cardiovascular disease" was a "condition [] contributing to death but not related to [immediate cause]." (Id. at 227.) The autopsy report, prepared by Robert A. Kurtzman, listed the immediate cause of death as "multiple injuries" and listed "other significant conditions" including "atrial fibrillation." (Id. at 237.)

Plaintiff submitted a claim for benefits under the Policy to LINA on November 3, 2008. LINA denied her claim. Key to this appeal is the language of several Policy provisions:

(Id. at 78) (emphasis added).

(Id.)

(Id. at 85) (emphasis added).

LINA denied Plaintiff's claim by finding that the specific circumstances of Viera's death did not constitute a covered event under the terms of the Policy. Specifically, LINA maintained that Viera's accident was excluded by the "Medical Condition Exclusion" of the Policy, which states that:

(Id. at 83.) LINA concluded that Viera's Coumadin treatment complicated his medical treatment and constituted a contributing factor to his death. LINA relied on a report by Dr. Mark H. Eaton, a medical doctor it had retained to review the accident reports and hospital records. Dr. Eaton reviewed the hospital records, the autopsy report, and the official Death Certificate in reaching his conclusion. Dr. Eaton reported that:

(Id. at 124.) Plaintiff administratively appealed the denial of benefits in a written letter to LINA. She chose not to supplement the record with information supporting her claim at that time. LINA affirmed its decision to deny benefits.

B. Procedural History

Plaintiff filed an ERISA action against LINA in the Court of Common Pleas of Philadelphia County, Pennsylvania. LINA removed the action to the United States District Court for the Eastern District of Pennsylvania pursuant to 28 U.S.C. §§ 1331 and 1441.3

In preparation for the litigation, Plaintiff hired an independent expert, Dr. Aaron J. Gindea, to conduct a review of the medical records. Dr. Gindea reported that:

(Id. at 320-21.)

The parties filed cross-motions for summary judgment. The District Court granted LINA's motion for summary judgment, denied Plaintiffs motion for summary judgment, and directed entry of judgment in favor of LINA. It found that LINA's denial of benefits was not an abuse of discretion. Plaintiff timely appealed and argues that the District Court should have reviewed LINA's decision de novo. In the alternative, she asserts that even under a deferential standard of review, a genuine issue of material fact exists such that summary judgment was inappropriate. Finally, she argues that the District Court misinterpreted the Medical Exclusion Provision of the Policy, which she maintains cannot be read to include atrial fibrillation or Coumadin treatment.

II.

A district court's determination of the proper standard to apply in its review of an ERISA plan administrator's decision is a legal conclusion which we review de novo. Grupo Protexa, S.A. v. All Am. Marine Slip, 20 F.3d 1224, 1231 (3d Cir. 1994).

We review a district court's grant of summary judgment de novo, applying the same standard the district court applied. Alcoa, Inc. v. United States, 509 F.3d 173, 175 (3d Cir.2007). We also review the legal interpretation of contractual language de novo. Heasley v. Belden & Blake Corp., 2 F.3d 1249, 1254 (3d Cir. 1993).

III.

A. Standard of Review of LINA's Benefits Denial

The Supreme Court has held that "a denial of benefits challenged under [ERISA] is to be reviewed under a de novo standard unless the benefit plan gives the administrator or fiduciary discretionary authority to determine eligibility for benefits or to construe the terms of the plan." Firestone Tire & Rubber Co. v. Bruch, 489 U.S. 101, 115, 109 S.Ct. 948, 103 L.Ed.2d 80 (1989). If the plan gives the administrator or fiduciary discretionary authority to make eligibility determinations, we review its decisions under an abuse-of-discretion (or arbitrary and capricious) standard.4 Metro. Life Ins. Co. v. Glenn, 554 U.S. 105, 111, 128 S.Ct. 2343, 171 L.Ed.2d 299 (2008); Doroshow v. Hartford Life & Accident Ins. Co., 574 F.3d 230, 233 (3d Cir.2009). "Whether a plan administrator's exercise of power is mandatory or discretionary depends upon the terms of the plan." Luby v. Teamsters Health, Welfare, & Pension Trust Funds, 944 F.2d 1176, 1180 (3d Cir.1991). There are no "magic words" determining the scope of judicial review of decisions to deny benefits, and discretionary powers may be granted expressly or implicitly. Id. However, when a plan is ambiguous, it is construed in favor of the insured. Heasley, 2 F.3d at 1258. "The plan administrator bears the burden of proving that the arbitrary and capricious standard of review applies." Kinstler v. First Reliance Std. Life Ins. Co., 181 F.3d 243, 249 (2d Cir. 1999).

Under the abuse-of-discretion standard, we may overturn an administrator's decision only if it is "without reason, unsupported by substantial evidence or erroneous as a matter of law." Miller v. Am. Airlines, Inc., 632 F.3d 837, 845 (3d Cir.2011) (quoting Abnathya v. Hoffmann-La Roche, Inc., 2 F.3d 40, 45 (3d Cir. 1993)). In determining whether an administrator abused its discretion, we must consider any structural conflict of interest as one of several factors. Estate of Schwing v. The Lilly Health Plan, 562 F.3d 522, 526 (3d Cir.2009).

In contrast, if we exercise de novo review, the role of the court "is to determine whether the administrator ... made a correct decision." Hoover v. Provident Life & Accident Ins. Co., 290 F.3d 801, 808-09 (6th Cir.2002) (alteration in original) (quoting Perry v. Simplicity Eng'g, 900 F.2d 963, 965 (6th Cir. 1990)). "The administrator's decision is accorded no deference or presumption of correctness." Id. at 809. The court must review the record and "determine whether the administrator properly interpreted the plan and whether the insured was entitled to benefits under the plan." Id.

The relevant language at issue in the Policy is the "Proof of Loss" provision, which provides: "Written or authorized electronic proof of loss satisfactory to Us must be given to Us at Our office, within 90 days of the loss for which claim is made." (App. at 85) (emphasis added). LINA argues that this language confers discretion upon them because they have expressly reserved the right to decide whether the proof of loss is satisfactory to them. Plaintiff argues that the language does not expressly and unambiguously confer discretion. Specifically, Plaintiff argues that the language can be interpreted in several different ways.5 Plaintiff argues that the alleged ambiguity should be resolved in her favor and de novo review should apply. The District Court rejected Plaintiff's argument and held that the "relevant policy language presents a clear grant of discretionary authority to LINA in deciding whether sufficient proof to support a claim has been submitted to shift the Court's review from de novo to the deferential abuse of discretion standard." Viera v. Life Ins. Co. of N. Am., 2010 WL 1407312, at *5 (E.D.Pa. Apr. 6, 2010). We disagree.

To begin with, we distinguish the language at issue here—in particular, the words "proof of loss satisfactory to Us"— from language in other plans that requires submission of "satisfactory proof," without reference to who must be satisfied. Most courts of appeals to consider the issue have concluded that the mere requirement to submit "satisfactory proof" does not confer discretion upon an administrator, and thus, does not insulate the administrator from de novo review. See, e.g., Perugini-Christen v. Homestead Mortg. Co., 287 F.3d 624, 626-27 (7th Cir.2002) (a policy requiring "satisfactory proof of Total Disability to [the insurer]" results in de novo review); Kearney v. Std. Ins. Co., 175 F.3d 1084, 1089-90 (9th Cir.1999) (en banc) (same where policy requires "receipt of satisfactory written proof"); Kinstler, 181 F.3d at 251-52 (same where policy requires insured to "submit[] satisfactory proof of Total Disability to [the insurer]").

On the other hand, courts of appeals interpreting policy language requiring submission of "proof of loss satisfactory to Us" have reached divergent conclusions, revealing the ambiguity inherent in the language. The United States Court of Appeals for the Second Circuit was the first appellate court to suggest that "satisfactory to us" language may not be sufficient to trigger abuse-of-discretion review. In Kinstler, 181 F.3d at 252, the court explained:

Id. at 252.

Shortly thereafter, the United States Court of Appeals for the Seventh Circuit squarely held that "satisfactory to us" language is insufficient to confer discretion. In Diaz v. Prudential Insurance Co. of America, 424 F.3d 635, 639-40 (7th Cir. 2005), the court broke from other courts of appeals, and its own prior precedent,6 by holding that the "satisfactory to us" language was no longer sufficient to compel abuse-of-discretion review. Diaz held that the "critical question is whether the plan gives the employee adequate notice that the plan administrator is to make a judgment within the confines of pre-set standards, or if it has the latitude to shape the application, interpretation, and content of the rules in each case." Id. Diaz relied on language from Herzberger v. Standard Insurance Co., 205 F.3d 327 (7th Cir.2000), for the proposition that Herzberger changed the course of Seventh Circuit jurisprudence on this issue. In so holding, it reaffirmed the safe harbor language it pioneered in Herzberger:

Diaz, 424 F.3d at 637 (quoting Herzberger, 205 F.3d at 331). However, the Diaz court went further than Herzberger by holding that "[n]o single phrase such as `satisfactory to us' is likely to convey enough information to permit the employee to distinguish between plans that do and plans that do not confer discretion on the administrator." Id. at 639.

The United States Court of Appeals for the Ninth Circuit followed the footsteps of the Seventh Circuit and held that "satisfactory to us" language does not "unambiguously provide discretion to the plan administrator." Feibusch v. Integrated Device Tech., Inc., 463 F.3d 880, 883 (9th Cir.2006) (applying de novo review). The Ninth Circuit adopted safe harbor language7 and explained that the "policy does not unambiguously indicate that the plan administrator `has authority, power, or discretion to determine eligibility or to construe the terms of the Plan, [and therefore] the standard of review will be de novo.'" Id. at 884 (quoting Sandy v. Reliance Std. Life Ins. Co., 222 F.3d 1202, 1207 (9th Cir.2000)). It reasoned that the term "satisfactory to us," "only arguably confer[red] discretion," and that therefore the ambiguity must be resolved in favor of the insured. Id. It also noted that although it endorsed the safe harbor language, it was not requiring "magic words." Id.

There is, however, a split among our sister courts of appeals regarding the impact of the "satisfactory to us" language. In contrast to the courts of appeals for the Second, Seventh, and Ninth Circuits, the First, Eighth, and Tenth Circuits have held that the "satisfactory to us" language confers discretion sufficient to insulate an administrator from de novo review. The First Circuit dealt with similar language in Brigham v. Sun Life of Canada, 317 F.3d 72 (1st Cir.2003). The policy at issue provided that the administrator "must be provided with such evidence satisfactory to us as we may reasonably require under the circumstances." Id. at 81 (emphasis in original). The court noted that "[c]ircuits that have considered similar language view the `to us' after `satisfactory' as an indicator of subjective, discretionary authority on the part of the administrator, distinguishing such phrasing from policies that simply require `satisfactory proof' of disability, without specifying who must be satisfied." Id. It concluded that the language "trigger[ed] discretionary review."8 Id. at 82.

Similarly, in Nance v. Sun Life Assurance Co. of Canada, 294 F.3d 1263, 1267-68 (10th Cir.2002), the Tenth Circuit held that the policy language adequately conferred discretion. The language at issue in the insurance policy required that "[p]roof must be satisfactory to Sun Life" before benefits would be paid. Id. at 1267. The court was careful to "caution [ ] that plan drafters who wish to convey discretion to plan administrators are ill-advised to rely on language that is borderline in accomplishing that task." Id. at 1268 n. 3. However, it ultimately held that the "satisfactory to Sun Life" language "suffice[d] to convey discretion to Sun Life in finding the facts relating to disability." Id. at 1268; see also Ferrari v. Teachers Ins. & Annuity Ass'n, 278 F.3d 801, 806 (8th Cir.2002) (a plan sufficiently conferred discretion because it "specifie[d] that the employee must provide written proof of continued total disability" and "that such proof must be satisfactory to [the plan administrator]").9

We find the reasoning of the Second, Seventh and Ninth Circuits persuasive. To be insulated from de novo review, a plan must "communicate the idea that the administrator not only has broad-ranging authority to assess compliance with pre-existing criteria, but also has the power to interpret the rules, to implement the rules, and even to change them entirely." Diaz, 424 F.3d at 639. We agree that "[n]o single phrase such as `satisfactory to us' is likely to convey enough information to permit [an insured] to distinguish between plans that do and plans that do not confer discretion on the administrator." Id.

Specifically, the language at issue here "does not alert the plan participant to the possibility that [LINA] has the power to re-define the entire concept of [a covered loss] on a case-by-case basis." Id. Indeed, the only discretion reserved by this single phrase, nested within a section wholly regarding the procedural requirements for submission of a claim, is "the inevitable prerogative to determine what forms of proof must be submitted with a claim—something that an administrator in even the most tightly restricted plan would have to do."10 Id. (emphasis in original). In other words, it is not clear whether "satisfactory to Us" means "electronic proof of loss [in a form] satisfactory to Us" or "electronic proof of loss [substantively and subjectively] satisfactory to Us." We resolve this ambiguity in favor of the insured:

Kinstler, 181 F.3d at 252 (emphasis added).

If an administrator wishes to insulate its decision to deny benefits from de novo review, we suggest that it adopt the following "safe harbor" language: "Benefits under this plan will be paid only if the plan administrator decides in [its] discretion that the applicant is entitled to them." Herzberger, 205 F.3d at 331. This is not to say that "magic words" are required for a policy to reserve discretion. See Luby, 944 F.2d at 1180. Instead, the Policy at issue here simply does not clearly indicate that LINA has discretion to "interpret the rules, to implement the rules, and even to change them entirely," and thus the District Court erred in applying abuse-of-discretion review rather than de novo review to LINA's decision. Diaz, 424 F.3d at 639.

Because we have concluded that a de novo standard of review applies, we need not reach Plaintiff's argument regarding LINA's conflict of interest in being both the payor and administrator of benefits. That issue is only pertinent to an abuse-of-discretion standard of review.11 On remand, the District Court must determine whether LINA properly denied Plaintiff recovery under the Policy. This determination may be based on any information before the administrator initially, Hoover, 290 F.3d at 809, as well as any supplemental evidence, such as Dr. Gindea's report. See, e.g., Luby, 944 F.2d at 1184-85 ("[A] district court exercising de novo review over an ERISA determination between beneficiary claimants is not limited to the evidence before the Fund's administrator."); Quesinberry v. Life Ins. Co. of N. Am., 987 F.2d 1017, 1025 (4th Cir.1993) (district courts have discretion during de novo review to consider evidence not before administrator); Perry, 900 F.2d at 966 (citing 2 S. Childress & M. Davis, Standards of Review § 15.2 (1986)).

B. The District Court's Interpretation of Policy Language

Although we have already determined that the District Court erred in applying an abuse-of-discretion standard, we consider nonetheless Plaintiff's second contention to provide guidance to the District Court on remand. Plaintiff argues that the District Court misinterpreted the Policy because the Medical Exclusion Provision was ambiguous at best. Specifically, she argues that LINA should not be able to apply the Exclusion to Viera's Coumadin treatment based on a canon of statutory construction, the last-antecedent rule, and the general maxim that ambiguous contract language should be construed against the drafter.12 The District Court rejected this argument and held that "although a strict application of the last-antecedent rule supports Plaintiff's interpretation, sufficient indicia of contrary meaning exist to overcome this maxim of interpretation." Viera, 2010 WL 1407312, at *10.

We review the legal interpretation of contractual language de novo. Heasley, 2 F.3d at 1254. The last-antecedent rule is a canon of statutory interpretation, but we have extended application of the rule to a life insurance policy as well. See J.C. Penney Life Ins. Co. v. Pilosi, 393 F.3d 356, 365-66 (3d Cir.2004). The rule provides "that qualifying words, phrases, and clauses are to be applied to the words or phrase immediately preceding and not to others more remote." Stepnowski v. C.I.R., 456 F.3d 320, 324 (3d Cir.2006) (quoting United States v. Hodge, 321 F.3d 429, 436 (3d Cir.2003)). In other words, if a sentence reads "A or B with respect to C," it should be interpreted as containing two items: (1) "A" and (2) "B with respect to C." Id. at 324 n. 7. However, the last-antecedent rule "is not an absolute and can assuredly be overcome by other indicia of meaning." Pilosi, 393 F.3d at 365 (quoting Barnhart v. Thomas, 540 U.S. 20, 26, 124 S.Ct. 376, 157 L.Ed.2d 333 (2003)).

The Medical Exclusion Provision at issue states:

(App. at 83.) Plaintiff argues that the placement of the comma immediately preceding the term "bacterial or viral infection" suggests that the term "medical or surgical treatment thereof" would not be extended to the other terms "sickness, disease, bodily or mental infirmity." In other words, Plaintiff contends that the Policy excludes coverage only for "medical treatment" of "bacterial or viral infection[s]" and does not exclude coverage for "medical treatment" of "bodily infirmities" like atrial fibrillation. The District Court agreed with Plaintiff's literal application of the last-antecedent rule. However, the District Court ultimately concluded that there were sufficient indicia of meaning that contradicted Plaintiff's interpretation. Specifically, the District Court pointed out that:

Viera, 2010 WL 1407312, at *10. The District Court appropriately looked to and analyzed the indicia of meaning in the Policy so as not to "contort the language beyond its limits." Pilosi, 393 F.3d at 365. Where the meaning of the contract language is clear, the last-antecedent rule should not be used to create ambiguity.

Plaintiff also argues that the inherent ambiguity in the plan must be construed against LINA under the doctrine of contra proferentem. "Whether an ambiguity exists is a question of law." 12th St. Gym, Inc. v. Gen. Star Indem. Co., 93 F.3d 1158, 1165 (3d Cir.1996). Under Pennsylvania law, an insurance contract is ambiguous where it: "(1) is reasonably susceptible to different constructions, (2) is obscure in meaning through indefiniteness of expression, or (3) has a double meaning."13 Lawson v. Fortis Ins. Co., 301 F.3d 159, 163 (3d Cir.2002). To be sure, we must construe ambiguous policy provisions against the drafter of the contract once a determination of ambiguity has been made, but the language at issue here is not ambiguous. Pilosi, 393 F.3d at 363; 12th St. Gym, 93 F.3d at 1166.

As noted above, Plaintiff's alternative reading of the provision under the last-antecedent rule is not reasonable. "Disagreement between the parties over the proper interpretation of a contract does not necessarily mean that a contract is ambiguous." 12th St. Gym, 93 F.3d at 1165. Where there is only one reasonable interpretation of a contract, that interpretation controls because "[s]traightforward language in an insurance policy should be given its natural meaning." Lawson, 301 F.3d at 162. The District Court correctly interpreted the Medical Exclusion Provision.

IV.

For the foregoing reasons, we will reverse in part, affirm in part, and remand to the District Court for proceedings consistent with this opinion.