*1156This case requires us to consider the boundaries of "payment based wholly on service as a member of a uniformed service" for the purposes of Social Security benefit calculations. We agree with the Social Security Administration's interpretation, and affirm the district court's decision.
I.
Donald Larry Martin appeals from the Social Security Administration (SSA)'s decision to reduce his monthly retirement insurance benefits in accordance with the Social Security Act's "windfall elimination provision." Martin and the SSA disagree on whether he is eligible for an exception to the provision that would prevent the reduction of his benefits.
A.
The Social Security Act does not distribute social security benefits as a flat percentage of a recipient's earnings. Instead, it adjusts benefits payouts so that individuals with lower "average indexed monthly earnings"1 are entitled to a greater percentage of those earnings than those with higher earnings.2 This allows low-income workers to receive a higher return on their Social Security contributions than higher-income workers.3
Further, not all employment is subject to Social Security contributions. The statutory scheme distinguishes between "covered" and "noncovered" employment. Covered employment is subject to various Social Security taxes, and associated retirement benefits are calculated to account for average indexed monthly earnings in the manner we described.4 Noncovered employment is exempt from Social Security taxes,5 but many noncovered positions include a separate annuity or pension.
Taken together, these elements of the default Social Security plan mean that a person who worked in both covered and noncovered employment might doubly benefit. Such a person might receive a pension or annuity from a noncovered employer while simultaneously receiving higher-than-warranted Social Security benefits-since the percentage of average indexed monthly earnings to distribute would be calculated only on the basis of any income from covered employment.6
The Act's "windfall elimination provision" helps eliminate the potential for double-dipping.
*1157It modifies the default formula to account for an individual who receives a monthly payment "based in whole or in part upon his or her earnings" for noncovered work.7 Such an individual will receive a smaller percentage of average indexed monthly earnings than he or she would receive under the standard formula.8
There are some exceptions to the windfall elimination provision, however. Primarily relevant here is subsection 415(a)(7)(A)(III)'s exception for any "payment based wholly on service as a member of a uniformed service," which we will refer to as the provision's "uniformed services exception."9 "[M]ember of a uniformed service" is not defined in the provision, but rather incorporates definitions from across the U.S. Code. In doing so, it encompasses members of the Army National Guard.10
B.
At issue is how this statutory scheme applies to someone who served as a National Guard "military technician (dual status)," also known as a "dual status technician." Congress has provided for two types of technicians to provide support to National Guard units: dual status technicians and non-dual status technicians.11 The two roles have similar job responsibilities,12 both are supervised by military adjutants general,13 and neither is subject to military discipline under the Uniform Code of Military Justice.14 There are several relevant differences, however: only dual status technicians are required as a condition of employment to maintain membership in the Selected Reserve15 and a specified military grade,16 and to dress in uniform while performing technician duties.17 Moreover, unlike non-dual status technicians, dual status technicians are "authorized and accounted for as a separate category of civilian employees"18 and are exempt from the competitive service19 and requirements for reductions in Department of Defense civilian personnel.20 Despite these differences, a dual status technician is "assigned to a civilian position as a technician,"21 and consistently *1158referred to as a civilian employee.22
C.
Martin was a National Guard dual status technician from 1982 to 2005, and a member of the Alabama Army National Guard during the same time period.23 In his administrative hearing in this case, he stated that "[o]n [the] weekend [he] was treated just like a soldier in the Alabama National Guard" and assigned to a military position. He further explained that he received "military pay" for his weekend drills with the National Guard and "federal civil service pay" for his weekday employment as a dual status technician. Neither his National Guard membership nor his employment as a dual status technician were covered employment for Social Security purposes.
In 2003, after Martin's National Guard unit was selected to go on a tour to Norfolk, Virginia, a doctor referred Martin to a medical board due to a prior asthma diagnosis. The medical board concluded that Martin was non-deployable, so Martin was transferred to a non-deployable unit and subsequently discharged on December 4, 2004.24 Because he was no longer a member of the National Guard, the civil service also terminated him from his job as a dual status technician, effective April 9, 2005.
Martin was eligible for three different payments as a consequence of these events. First, he began receiving disability retirement payments from the federal civil service in 2005.25 Second, he was eligible for military retired pay due to his National Guard service and prior active and inactive military duty in the 1970s, and began receiving those payments once he turned sixty in 2010. Finally, Martin was granted Social Security retirement insurance benefits in 2012 based on covered employment he had performed before the age of thirty-two.
Martin's Social Security retirement insurance benefits are at the heart of this case. The SSA determined that because Martin was also receiving civil service disability retirement payments, his Social Security benefits should be reduced under the windfall elimination provision. It correspondingly reduced his Social Security retirement insurance benefits from $658.90 per month to $439.20 per month. This reduction solely reflected Martin's receipt of the civil service payments; it did not take into account his military retired pay, as that was indisputably based on his performance of military duties.
Martin sought recourse against this determination from the SSA-requesting reconsideration from the SSA, a determination by an administrative law judge (ALJ), and review by the SSA Appeals Council26 -and was denied at each step. Once he received the agency's final determination, he sought review from the district court, which agreed with the agency27 and denied Martin's subsequent motion to amend its judgment. He timely appealed to this Court.
*1159Martin's position is that any payments he now receives based on his employment as a dual status technician are "payment[s] based wholly on service as a member of a uniformed service," and are therefore subject to the uniformed services exception to the windfall elimination provision. As such, he claims that the disability retirement payments should not be taken into account to reduce his Social Security payments. In turn, the SSA claims that the uniformed services exception should not be construed to extend to dual status technician employment.
II.
We review findings of fact by the Commissioner of Social Security for substantial evidence,28 and review the Commissioner's legal decisions de novo.29 We will therefore review the construction of the uniformed services exception de novo, albeit potentially subject to the principles of deference we apply to an agency's statutory interpretation.30
A.
At a minimum, we give an agency interpretation deference under Skidmore v. Swift & Co. corresponding to the "thoroughness evident in its consideration, the validity of its reasoning, its consistency with earlier and later pronouncements, and all those factors which give it power to persuade, if lacking power to control."31 This recognizes an agency's specialized experience and information-seeking capacities, as well as the value of uniformity.32
If an agency's interpretation meets a certain threshold, we instead give heightened deference according to the two-step framework laid out in Chevron, U.S.A., Inc. v. National Resources Defense Council, Inc .33 Under that framework, we must defer to an agency's reasonable interpretation of an ambiguous statute.34
B.
Since Chevron , the Supreme Court has clarified what some refer to as "step zero" of Chevron35 : the threshold requirement that an agency interpretation be of the sort that warrants Chevron analysis in the first instance. Specifically, in United States v. Mead Corp. , the Court concluded that the principles underlying Chevron are only applicable where Congress explicitly or implicitly "expect[s] the agency to be able to speak with the force of law when it addresses ambiguity in the statute or fills a space in the enacted law," and the agency actually acts in line with that expectation.36 This will frequently be apparent when the agency acts pursuant to its authority to engage in notice-and-comment rulemaking or formal adjudication on *1160the topic, but those formal procedures are not universally necessary.37 Importantly, even when an agency interpretation is not eligible for Chevron deference because it does not overcome step zero, it may still be entitled to Skidmore deference.38
The SSA's interpretation of the uniformed services exception appears in three different agency issuances. Most importantly, the agency issued an "acquiescence ruling" in response to Petersen v. Astrue ,39 an Eighth Circuit case holding that the uniformed services exception applies to dual status technicians. This ruling-which was published in the "Notices" section of the Federal Register-lacks "the force and effect of the law or regulations," but binds internal components of the SSA.40 It concluded that the SSA would only apply Petersen 's interpretation within the Eighth Circuit, and would continue to treat dual status technicians as ineligible for the exception everywhere else.41 The agency's interpretation also appears in its "Program Operations Manual System" (POMS), which lays out internal procedures for the SSA.42 Finally, it loosely appears within the SSA's discussion of its implementing regulation for the uniformed services exception.43
The parties seemingly agree that the SSA's interpretation, couched in these issuances, clears the "step zero" hurdle such that we should apply Chevron 's ordinary two-step process. Martin makes no argument that the SSA's interpretation does not speak sufficiently with the force of law to qualify for Chevron deference, and indeed appears to assume that the Chevron framework applies.44 For its part, the SSA
*1161argues that any objections under Chevron step zero are waivable, and that Martin has waived them by failing to contest the applicability of Chevron . The district court analyzed the step zero issue and held that the SSA's interpretation was eligible for Chevron deference,45 but acknowledged that it reached that conclusion in part because Martin had failed to contest the issue.46
This raises two unsettled issues. The first is whether "step zero" of Chevron is waivable-that is, whether the parties may agree that the court must grant Chevron deference if a statute is ambiguous and the agency's construction is reasonable, even if the agency interpretation would not ordinarily be eligible for Chevron deference under Mead and its progeny.47 Other circuits have split on this issue, with some concluding that an objection to the Chevron framework is a non-jurisdictional argument that parties may waive,48 and others analogizing Chevron deference to a standard of review that the court must independently assess.49
The second is whether, if we concluded that step zero is not waivable, the SSA's interpretation would meet Mead 's threshold requirement. The district court emphasized a number of aspects of the SSA's acquiescence ruling that appear to warrant deference, such as the intricacy of the statutory scheme the SSA must administer and the consistency of the SSA's interpretation.50 But there are also several factors *1162that counsel against granting the acquiescence ruling Chevron deference, like that the SSA disavows that its acquiescence rulings have the force of law, its relatively cursory rationale, and the lack of notice-and-comment procedure.51 Further, while it is unclear whether the acquiescence ruling would qualify for Chevron deference under a step zero analysis, the POMS entry and regulation preamble are more plainly not Chevron -eligible.52
We do not need to unravel whether the parties can agree to bypass Chevron step zero or whether, if they cannot, the SSA's interpretation would survive that analysis. Instead, we conclude that even under Skidmore deference, the SSA has the best reading of the uniformed services exception.
III.
The crux of Martin's position is that work as a dual status technician is "essentially military" in nature, and therefore his employment as a dual status technician was rendered "wholly ... as a member of a uniformed service." After parsing the provision's text, giving the SSA's interpretation the deference it is due under Skidmore , we cannot agree.
A.
As we have observed, the SSA's interpretation is at least entitled to deference based on its power to persuade, accounting for the "thoroughness evident in its consideration, the validity of its reasoning, [and] its consistency with earlier and later pronouncements."53 This recognizes that informal agency interpretations "constitute a body of experience and informed judgment to which courts and litigants may properly resort for guidance."54
Here, the SSA administers a "highly detailed" statutory scheme and "can bring the benefit of specialized experience to bear on the subtle questions in this case."55 It previously considered the issue presented *1163by Martin and resolved to preserve its longstanding interpretation of the provision based on its reading of the legislative history.56 Further, the SSA POMS provides specific, detailed instructions on how to apply the SSA's interpretation, especially in light of the Petersen decision that governs claims by residents of the Eighth Circuit.57 Taken together, these considerations reflect a carefully reasoned agency interpretation that meshes with the SSA's overall administration of the Social Security Act-exactly the type of interpretation that warrants a reasonable degree of deference under Skidmore . While this deference may not override our reading of the provision's plain meaning,58 it will inform our interpretation of any text that is more difficult to untangle.
B.
We begin with the text of the uniformed services exception.59 We must first determine whether the uniformed services exception's language "has a plain and unambiguous meaning."60 If the meaning of the exception is "inescapably ambiguous," we may look outside the statutory text to aid in our interpretation.61
In relevant context, the provision reads as follows:
(7)(A) In the case of an individual whose primary insurance amount would be computed under paragraph (1) of this subsection, who-
(i) attains age 62 after 1985 (except where he or she became entitled to a disability insurance benefit before 1986 and remained so entitled in any of the 12 months immediately preceding his or her attainment of age 62), or
(ii) would attain age 62 after 1985 and becomes eligible for a disability insurance benefit after 1985,
and who first becomes eligible after 1985 for a monthly periodic payment ( ... but excluding ... (III) a payment based wholly on service as a member of a uniformed service (as defined in section 410(m) of this title)) which is based in whole or in part upon his or her earnings for service which did not constitute ... [covered employment], the primary insurance amount of that individual during his or her concurrent entitlement to such monthly period payment and to old-age or disability insurance benefits shall be computed or recomputed under subparagraph (B).62
We agree with Martin, and the SSA does not contest, that "wholly" has a plain meaning in this context-it means "to the full or entire extent" or "to the exclusion of other things."63
*1164The word "service," in the first sense in which it is used in the provision, does not have a definite meaning in context. It could be taken to relate to employment generally, or it could be read to be specific to military membership.64 Resolving this will not decisively clarify the provision's scope, however. If we read "service" in its broader sense to constitute employment, it will still be limited by the requirement that it be performed "as a member of a uniformed service," as we will explain. If we read it in its narrower scope to constitute solely military service, we must still determine what activities fall within the sweep of military service.
This brings us to the use of the word "as" to limit what service qualifies for the uniformed services exception. In the context of the requirement, "as" appears to limit the uniformed services exception only to payments for work performed in one's capacity or role as a member of the uniformed services.65 As the SSA points out, if Congress had intended the uniformed services exception to cover any payments made to someone who had been a member of a uniformed service, it could have accomplished that objective much more simply by excepting payments "to" a member of a uniformed service or payments for service "by" a member of a uniformed service.66 To put a finer point on the issue, it is not enough that Martin was a member of a uniformed service at the same time he performed the noncovered employment at issue. Rather, the work for which Martin now receives civil service disability retirement payments-his employment as a dual status technician-must have been performed in his role as a member of a uniformed service.67 On this point, too, there is no serious dispute between the parties.68
*1165The controversy is ultimately over what it means to perform service wholly in one's capacity or role as a member of a uniformed service . The text of the uniformed services exception is of limited use here; while it cross-references and incorporates definitions across the U.S. Code, at bottom it only clarifies that members of the United States Army National Guard are "member[s] of a uniformed service."69 It does not further define service performed as a member of the National Guard, and therefore does not resolve whether the civil service payments at issue were wholly for work Martin performed as a member of the National Guard, or whether they were at least partially for work he performed outside of that role.
C.
But we are not limited to the twenty-one words of the uniformed services exception. We must also look to Congress's conception of the dual status technician role, as evidenced by the rest of the statutory scheme.70 Martin notes the many elements of the dual status technician role that appear to place it within the bounds of service as a member of the National Guard. Specifically, he observes that he was required to maintain membership in the Alabama National Guard to preserve his position as a dual status technician; that dual status technicians are "authorized and accounted for as a separate category of civilian employees";71 that dual status technicians "shall only be reduced as part of military force structure reductions," in contrast to reductions in Department of Defense civilian personnel;72 that Martin's job was administered by a military adjutant general;73 and that military technicians may be employed in "the administering ... or training of the National Guard."74 These aspects led the district court and the administrative law judge to concede that the dual status technician role is "essentially military" in nature.75
Martin's work as a dual status technician was distinct from his National Guard service in important ways, though. Congress consistently refers to dual status technician employment as a civilian position.76 Martin acknowledges that he performed his technician work during the work week for federal civil service pay, and took up his military position on the *1166weekends for military pay. Now that Martin no longer serves in the National Guard or as a dual status technician, he receives separate military retired pay-including for his twenty-seven years of National Guard service-and civil service disability payments.77 Even the use of the title "dual status" suggests that dual status technicians are employed not just in their capacity as members of the National Guard.
The critical issue is therefore how the word "wholly" interacts with the nature of the dual status technician position. By its plain meaning, "wholly" limits the payments covered by the uniformed services exception: even if dual status technician employment is essentially military, it is not subject to the uniformed services exception if it is not wholly military in nature. Accounting for all of the features of the dual status technician role, we find it difficult to conclude that a dual status technician wholly performs that role as a member of the National Guard.
D.
Recognizing that the plain text of the provision itself is not necessarily determinative of what it means to perform service "as a member of a uniformed service," nothing Martin has presented extrinsic to the statutory scheme convinces us of his position. Martin urges us to consider several additional sources, but none of them indicate that the uniformed services exception covers payments for work performed as a dual status technician.
He emphasizes the contrasts between dual status technicians and other National Guard technicians, but this comparison does not sustain a conclusion that dual status technicians wholly perform their service as members of the National Guard. It is true that the role of "military technician (dual status)" is defined in a section of the U.S. Code separate from the section defining the role of "non-dual status technician," and that non-dual status technicians need not maintain membership in the National Guard or wear military uniform.78 For all other purposes, however, non-dual status technicians appear able to perform the same responsibilities as dual status technicians,79 and they are "employ[ed] and administer[ed]" by the same adjutants general.80
Nor are other portions of the U.S. Code helpful in establishing the meaning of the uniformed services exception. Martin isolates the use of the phrase "based wholly on service as a member of a uniformed service" in 42 U.S.C. § 402(k)(5)(B)(i), which provides a similar exception to a provision reducing old age and survivor's insurance benefits, but that context does not bring information on its interpretation.81 Martin also notes that "[f]ull-time National Guard duty" encompasses "training or other duty[ ] performed ... in the member's status as a member of the National Guard,"82 and that "training or duty"
*1167extends to "[s]upport of operations or missions undertaken by the member's unit at the request of the President or Secretary of Defense."83 In context, this definition of "training or duty" only suggests that National Guard members may permissibly be called upon to perform tasks other than "assembl[ing] for drill and instruction ... at least 48 times each year" and "participat[ing] in training ... at least 15 days each year."84 And, while "[s]upport of operations or missions undertaken by the technician's unit at the request of the President or the Secretary of Defense" is one of the "additional duties" that a National Guard technician may be called upon to perform,85 it is not one of the technician's core duties-instead, employing a technician for operation or mission support is only permissible "to the extent that ... [it] does not interfere with the performance" of those core duties.86 This does not establish that work performed as a dual status technician constitutes work performed as a member of the National Guard.
Finally, Martin urges that the legislative history of the uniformed services exception brings evidence that Congress intended the exception to encompass employment like the dual status technician role at issue here. It does not. Rather, the legislative history only reflects an effort by Congress to harmonize the treatment of military pensions for active and inactive military service.87 It does not show that Congress intended to exclude dual status technicians from the windfall elimination provision. The legislative history of the National Guard Technicians Act of 1968 also offers no special guidance; on one hand, Congress evidently recognized that the vast majority of technicians would be dual status and that the program would be "organized and operated along military lines,"88 but on the other hand, it consistently emphasized that part of even a dual status technician's work would be civilian employment.89
*1168* * *
After using the interpretive tools at our disposal, we conclude-accounting for the unique nature of the dual status technician position and the deference we have determined we owe the SSA's interpretation under Skidmore -that Martin did not perform his dual status technician employment wholly as a member of a uniformed service. As a result, payments based on that employment do not qualify for the exception.
IV.
We recognize in reaching this result that we are at odds with the Eighth Circuit, which held in Petersen v. Astrue that the exception unambiguously applied to a dual status technician.90 In doing so, the Eighth Circuit emphasized that dual status technicians are required to maintain National Guard membership and to wear uniforms while on duty, noting that these were "unique National Guard technician requirements" that a dual status technician performed in his work as a member of the National Guard.91 It further rejected the SSA's proposal to read what the court referred to as a "military duty" requirement into the statute, noting that all the exception requires is that the service be conducted as a member of a uniformed service.92
For the reasons we have explained, we do not think the requirements of the dual status technician position are sufficient to place dual status technicians within the sweep of the exception-especially given the provision's use of the word "wholly." We agree with the Eighth Circuit that not all service performed "as a member of a uniformed service" must have characteristics of military duty . We further agree that certain aspects of a dual status technician's employment may ultimately be performed as a member of a uniformed service.93 Given the dual nature of the role and the civilian elements we have discussed, however, we cannot agree that the employment is performed wholly as a member of a uniformed service. We must instead hold that the uniformed services exception does not apply in Martin's case.
V.
We affirm the judgment of the district court.