concurring:
¶ 83 I join Justice Wilkins’s review of the statutory and procedural background of this case and note in particular my agreement with his cautionary remarks about perceived attempts to intrude on the constitutional obligations of this court to be the independent voice of the rule of law under our form of government. I also agree with Justice Wilkins that the plaintiffs have standing to bring their facial challenge to H.B. 213 and that their facial challenge fails. I therefore concur in the analysis of Part I and in the result of Part 11(1), as well as with its conclusion that the language concerning the meaning of “eligibility to receive retirement benefits” in H.B. 213’s predecessor statute is ambiguous.
¶ 84 Like Justice Parrish, I conclude that the statute that H.B. 213 supplanted survives facial attack on the strength of the presumption that the legislature cannot be bound unless it manifests a clear intention to create or vest a private property right. I find it unnecessary, however, to set out on a trek into the uncharted terrain of extrinsic evidence in the hope of resolving the ambiguity that infests the 2004 amendment to section 67-19-14.2, nor would I reach the question of whether the State undertook a voluntary obligation.
¶85 Although the lead opinion makes a persuasive case for the ambiguity of section 67-19-14.2, the close textual exegesis offered by Justice Parrish to defend her view that the statute plainly and unambiguously conditions “eligibility to receive retirement benefits” on actual retirement compels me to respond with a text-based analysis of my own that reaches the contrary result.
¶ 86 The portion of the text of the 2004 version of section 67-19-14.2 that bears on the question of whether the statute created a property right in the Option reads as follows:
(1) (a) There is created the “Unused Sick Leave Retirement Option Program.”
*227(b) An agency may offer the Unused Sick Leave Retirement Option Program to an employee who is eligible to receive retirement benefits in accordance with Title 49, Utah State Retirement and Insurance Benefit Act.
Utah Code Ann. § 67-19-14.2(l)(a)-(b) (2004).
¶ 87 According to Justice Parrish, this provision cannot create a property right in the Option because an agency that chooses to adopt the Option program does not offer it to an employee until the employee has retired. This is not, of course, an interpretation that can be harvested from the plain language of the statute. An “employee who is eligible to receive retirement benefits” to whom the employer agency offers the Option need not necessarily be an employee who has retired. Indeed, it is plausible, and in my view probable, that the phrase is meant both to disqualify employees excluded or exempted from participation in one of the State’s retirement systems, such as temporary employees, see, e.g., Utah Code Ann. § 49-12-203 (2002), and to make the offer available to employees who have satisfied the age and service requirements for retirement but who have not yet retired.
¶ 88 The contention that the Option cannot be offered to an employee until the employee has retired must derive from the phrase “in accordance with Title 49, Utah State Retirement and Insurance Benefit Act.” Utah Code Ann. § 67 — 19—14.2(l)(b). In the interpretation urged on us by the State, and in large measure adopted by Justice Parrish, the clause “in accordance with” that links the phrase “an employee who is eligible to receive benefits” with “Title 49” means that Title 49 should be canvassed for a provision that offers a supplemental definition for just who “an employee who is eligible to receive benefits” might be. The State and Justice Parrish contend that this defining language appears in section 49-12-401, which details the status of an employee who “is qualified to receive an allowance from this system.” They reason that such an employee is the same employee described as one “who is eligible to receive retirement benefits” in section 67-19-14.2(l)(b). Since the employee described in section 49-12-401 must have satisfied both the age and service conditions for retirement and formally applied to retire, formal retirement must be imparted into section 67-19-14.2(l)(b) as a condition precedent to becoming an offeree of the Option. Two fundamental flaws undermine this reasoning.
¶ 89 First, the premise that the reference to Title 49 in section 67 — 19—14.2(1)(b) inevitably compels the importation of the restrictive formal retirement requirement of section 49-12-401 is erroneous. A review of the text of the version of section 67-19-14 that the 2004 amendment modified discloses why. That iteration of the conversion options available for unused sick leave states that “[a]n employee must be eligible for retirement benefits to qualify for the program.” Utah Code Ann. § 67 — 19—14(l)(a)(iv) (1999).
¶ 90 This is a phrase that is less susceptible to competing interpretations than its 2004 successor. It communicates the unambiguous message that if a State agency offers a program that permits agency employees to convert their unused sick leave, an employee who has met the age and service requirements for retirement but who has not yet formally retired may participate. In fact, this language likely excluded employees who had, for example, retired before the genesis of an unused sick leave conversion program in 1975.
¶ 91 The phrase “[a]n employee must be eligible for retirement benefits to qualify for this program” has enjoyed an enduring presence within section 67-19-14. It first appeared in 1983. In that year, the legislature amended the unused sick leave conversion provision to accommodate the legislature’s desire to supplement the original rationale for providing employees the opportunity to convert unused sick leave into health and medical insurance, that is, the reduction of sick leave abuse, with an incentive for state employees to retire early, with the goal of controlling the growth of the state workforce.1 Utah Code Ann. § 67 — 19—14(2)(d). *228It was preserved when the statute was amended in 1998 and again in 1999. Did the 2004 amendment to section 67-19-14 result in a substantive change to pare back the class of those employees qualified to participate in the program to employees who had provided formal notice of retirement? No.
¶ 92 Neither the sponsor of the 2004 amendment nor anyone who rose in the legislature to speak to the merits of the amendment indicated that it would bring about any modification of the substance of the pre-amendment language. Yet, the State’s reading of the 2004 amendment requires a dramatic interpretive shift to a meaning squarely at odds with the legislative history. This alone does not make the State’s interpretation wrong. Indeed, the legislative history of the amendment would be irrelevant if it proved to be at odds with the unambiguous plain meaning of its text. The 2004 amendment can, however, be read to conform its interpretation to the plain meaning of its predecessor eligibility language acknowledging that an employee acquired a property right in her unused sick leave without the need to submit formal notice of an intent to retire.
¶ 93 The central alteration made by the 2004 amendment to the then-existing eligibility language was the replacement of the concluding phrase “to qualify for the program” with “in accordance with Title 49, Utah State Retirement and Insurance Benefit Act.” The concept of eligibility is not, however, displaced by the amending language. This is important. Even if we were to limit our inspection of Title 49 to the sections cited by Justice Parrish, we would nevertheless not be free to ignore the text of section 67-19-14.2(l)(b) that expressly renders the Option available to an employee “who is eligible to receive retirement benefits.” (emphasis added).
¶ 94 It is significant that the pre-2004 statutes contained both the words “eligible” and “qualify.” These two words persist in the 2004 amendment, but in an altered context. Because “eligible” and “qualify” appear prominently in every configuration of statutes relating to retirement, we take a closer look at them. The pre-2004 phrase “[a]n employee must be eligible for retirement benefits to qualify for the program” may be broken down into two components, one assembled around “eligible,” and the other around “qualify.” We start with the first half of the phrase, “[a]n employee must be eligible for retirement benefits.” There is no ambiguity in this phrase, and thus no occasion to turn to extrinsic sources to divine its meaning. We first observe that “eligible” is a word brimming with potential. That is, to be eligible, one may be desirable, fully capable of choosing or being chosen, but still uncommitted. Just as a bachelor is eligible to marry by choosing to do so, eligibility is defined by the ultimate choice or step a party must complete in order to realize the matter. This is why a boy who is under the legal marriage age is not yet eligible to marry— there is no decision or step that the boy can make or take to allow him to marry. So it is with the issue now before us. An employee is eligible for retirement benefits when there exists an election that she can make to start benefits flowing. Such a point could not be on the employee’s first day of work — presumably there is nothing the employee could do at that point to start to receive retirement benefits. However, without more information, we cannot be certain that the new employee is ineligible to receive retirement benefits because nothing in the statute explicitly states at what point an employee can choose to begin receiving those benefits. All the pre-2004 statute told us is that an employee must be eligible to “qualify for the program.”
¶ 95 The most logical interpretation of the link between “eligible” and “qualify” is that the right to elect to receive retirement benefits — to be eligible for those benefits — is one, but not necessarily the only, requirement to access the program.
¶ 96 Therefore, it must be established when an employee would be qualified. The best answer is found in section 49-12-401, which tells us when a member is qualified to receive a retirement allowance. In essence, this section states that someone is qualified to receive an allowance when she has accrued *229a specified number of service credits and attained a certain age, and then ceased work and filled out the requisite paperwork. Therefore, one must ask, how can an employee become eligible to qualify? As discussed above, one is eligible when she can choose to effectuate the matter for which she is eligible. The only possible answer is that she is eligible to qualify when she has accrued the mandatory service credits and age, so that she can choose, at her discretion, when to complete the qualification requirements by ceasing work and filling out the retirement paperwork.
¶ 97 As mentioned above, the 2004 amendment to section 67-19-14 was not intended to effectuate any substantive changes to the statute, but merely to clarify its substance. This description of the amendment is supported by what was done to section 67-19-14.2(l)(b). There, the statute dropped “to qualify for the program” and replaced it with the language quoted above, “in accordance with Title 49, Utah State Retirement and Insurance Benefit Act.” Where there may have been some initial doubt before as to where one could discover the qualifications for receiving the benefits provided by section 67-14-19, it was replaced with an explicit reference to Title 49. Of utmost importance is the fact that the term “eligible” remained in the statute while pointing to Title 49. The first line of section 49-12-401 states that “[a] member is qualified to receive an allowance from this system when,” and then outlines the requirements for qualification as discussed above. The key is that although the word “qualify” was removed from the text of section 67-19-14.2, it was preserved by the reference to Title 49 which replaced it, and which begins by describing the qualification requirements. Therefore, the 2004 amendment must be read, as its predecessor read, that an agency can offer the program to an employee who is eligible to qualify for the program — in other words, to someone who has accrued the service credits and attained the age outlined by section 49-12-401, but who has yet to effectuate that eligibility by ceasing employment and filling out the retirement paperwork.
¶ 98 This understanding is enforced by a more comprehensive look at Title 49. Taken as a whole, the content of Title 49 can easily support the conclusion that an employee acquires a property interest in unused sick leave when she satisfies the age and service requirements for retirement without regard to whether she has submitted an application to retire.
¶ 99 Section 49-11-102(34) defines “retiree” as “an individual who has qualified for an allowance under this title.” This definition is in complete harmony with section 49-12-401 which, in sub-parts (b) and (c), requires the submission of a formal application to retire and satisfaction of age and service requirements before “[a] member is qualified to receive an allowance from this system.” Put another way, the “member” in section 49-12-401 is a “retiree” as defined in section 49 — 11— 102(34). It is obvious that not every “employee eligible to receive retirement benefits” is a retiree, yet under the State’s statutory interpretation, they must be.
¶ 100 Title 49’s definition of “retirement” further exposes the weakness of relying solely on the text of section 49-12-401. Section 49-11-102(35) states that “ ‘Retirement’ means the status of an individual who has become eligible, applies for, and is entitled to receive an allowance under this title.” Under this definition, the “member” identified in section 49-12-401 who is “qualified to receive an allowance” is a “retiree” as defined in Title 49 and has also entered the realm of “retirement” because she has met the three conditions for retirement: she has become eligible for retirement, she has applied for retirement, and she is entitled to receive an allowance. It is clear from the definition of retirement that eligibility to receive retirement benefits is a status different than retirement. Because the status defined as “retirement” is achieved by complying with the requirements of section 49-12-401 to file a formal application for retirement and to satisfy the age and service standards, and because mere eligibility to receive retirement benefits satisfies but one of the three elements of “retirement,” an employee must logically be capable of being eligible to receive retirement benefits without filing a formal application to retire.
*230¶ 101 Section 49-12-701 underscores the point that under Title 49 an employee’s eligibility to receive retirement benefits does not require an employee to file a formal application to retire. Title 49 defines the eligibility for and the benefits of early retirement. Section 49-12-701(l)(a) makes early retirement available if “the member is eligible for retirement under Section 49-12-401, or has 25 years of service credit.” The only reasonable interpretation of this provision is that the right to choose to become a retiree under section 49-12-401, in other words to become “eligible” for retirement, is separate and independent from actually electing to retire and undertaking the tasks — most notably the submission of a formal application for retirement — necessary to make the employee “qualified to receive an allowance” under section 49-12-401.
¶ 102 Finally, it is unclear to me why section 49-11-103(2) should be excluded from the provisions of Title 49 that should be considered under the “in accordance” directive of section 67-19-14.2. This section states that “[Title 49] shall be liberally construed to provide maximum benefits and protections consistent with sound fiduciary and actuarial principals [sic].”
¶ 103 While I have considerable confidence in the correctness of this textual interpretation, I do not discount the legitimacy of Justice Parrish’s closely reasoned approach. I therefore stop short of asserting that my interpretation has won the day and that section 67-19-14.2 should be crowned with my reading as its sole, unambiguous construction. I am, instead, content to pursue the more modest objective of reinforcing the lead opinion’s claim that the statute is ambiguous.
¶ 104 Having offered up my interpretation of the statute central to this appeal, I turn to interpreting the law that governs how an ambiguous statute that purports to create a vested private property right should be evaluated when confronted by a facial challenge to its constitutionality. The key feature of this law is the policy-based principle that the legislative branch should be free to respond to the changing needs and will of the people. The law acknowledges the fundamental need for legislative flexibility and accountability when it imposes more rigorous demands on those who would claim that the legislature has bound itself by statute to duties and obligations that may mature in the future to demonstrate with particular clarity the legislature’s intent to assume such future duties.
¶ 105 Owing to the unique policy considerations that attend to commitments made by the legislature, I would end the facial-challenge inquiry into whether a statute creates a vested property right upon a finding that the statute is ambiguous. It is unnecessary and contrary to the presumption against the creation of statutorily-vested property interests to take the next step typically taken when confronted with statutory ambiguity and examine extrinsic evidence, most notably legislative history, for guidance on the intent of the statute.
¶ 106 I hasten to add that although in this instance the State is rewarded for successfully enacting a statute remarkable for its impenetrability (during the course of this appeal I have mused over how a lawyer who might have been visited by a state employee in late 2004 would have responded to her request for an opinion concerning the status of her unused sick leave), any legislative body that chooses to adopt as a strategy the notion that there is victory in opacity would, besides betraying the trust of the people, find that outside the context of a facial challenge to a statute, ambiguity would offer scant defense against the claim of a vested property right.
¶ 107 The voluntary undertaking exception to the presumption against the statutory creation of vested property rights provides parties who believe that they have sustained damage through the unconstitutional deprivation of a statutorily-conferred property right the opportunity for redress under circumstances where no statute clearly creates that right. Buchner v. Kennard, 2004 UT 78, 99 P.3d 842. The lead opinion suggests that such a voluntary undertaking must supplement an expressly-created statutory obligation. This does not go far enough. Correctly understood, the exception includes the use of evidence of a voluntary undertaking to resolve a statutory ambiguity that bears on the existence and scope of a claimed vested *231property right. In this setting, evidence of a voluntary undertaking would be identical in its form and purpose to extrinsic evidence that we call upon routinely to aid in the resolution of statutory ambiguities. This formulation of the exception would thereby compliment my central proposition that the presence of ambiguity itself should defeat a claim that a statute has conferred a vested property right.
. The early retirement program that was created by the 1983 amendments and which at that time was grafted onto section 67-19-14 was disconnected from the unused sick leave provisions and *228recodified in Title 49. Utah Code Ann. § 49-12-701.