ORDER REVERSING AND DIRECTING COMMISSIONER TO CALCULATE BENEFITS WITHOUT APPLYING THE WINDFALL ELIMINATION PROVISION

The matter before me is plaintiffs Complaint [# 1]2 filed June 15, 2011, seeking review of the Commissioner’s decision determining the monthly amount of retirement insurance benefits to which plaintiff is entitled under Title II of the Social Security Act, 42 U.S.C. § 401, et seq. I have jurisdiction to review the Commissioner’s final decision under 42 U.S.C. § 405(g). The matter has been fully briefed, obviating the need for oral argument. I reverse the decision and direct the Commissioner to calculate plaintiffs benefits without applying the Windfall Elimination Provision.

*1109I. FACTUAL AND PROCEDURAL BACKGROUND

Plaintiff, originally a citizen of Spain, emigrated to the United States in 1968 and became a naturalized citizen in 1984. He retired in 1997 and began receiving retirement insurance benefits at that time. In 2001, plaintiff applied for and was granted pension benefits from Spain. After the Commissioner received notice of these benefits, he recomputed and reduced plaintiffs retirement income benefits pursuant to the Windfall Elimination Provision (“WEP”), 42 U.S.C. § 415(a)(7)(A).

Plaintiff disagreed that the WEP applied to his Spanish benefits, and filed a motion for reconsideration. Following denial of that motion, plaintiff requested a hearing before an Administrative Law Judge. This hearing was held on October 19, 2005. The ALJ found that the WEP was properly applied to reduce the amount of plaintiffs retirement income benefits. The Appeals Council denied review, and plaintiff appealed to the federal district court. The court granted the Commissioner’s motion to remand in order to submit English translations of pertinent documents. Nevertheless, the Appeals Council ultimately affirmed the ALJ’s unfavorable decision.

Plaintiff then filed an appeal this court. I remanded the case to the Commissioner for further proceedings to

develop the record regarding the particulars of SOVI [Seguro Obligatorio de Vejeze Invalidez, the Spanish pension program under which plaintiff has received benefits], [3] including but not limited to, whether benefits thereunder are based on earnings, and to determine whether the express language of the statute and its implementing regulations can be squared with the relevant POMS’s [sic] guidelines.

(Tr. 257.) Pursuant to this mandate, the Appeals Council vacated the prior decision and remanded the case. A second hearing was held on December 1, 2010. The ALJ concluded that plaintiffs SOVI benefits were subject to the WEP, but because the recording of that hearing could not be located, the Appeals Council vacated that decision and remanded for yet another hearing. This most recent hearing was held on July 9, 2012, and the ALJ concluded again that plaintiffs Spanish pension benefits were subject"to reduction under the WEP. This appeal followed.

II. STANDARD OF REVIEW

Under the Social Security Act, an individual who is at least 62 years old and is otherwise “fully insured” as defined by the Act4 is entitled to receive monthly retirement insurance benefits. See 42 U.S.C. § 402. The amount' of this payment is called the primary insurance amount (“PIA”). See id. § 415(a)(1). The PIA is calculated and may be adjusted based on a number of different considerations and circumstances, one of which is whether the claimant receives, in addition to retirement income benefits under the Act, other monthly periodic payments based on “non-covered” employment, that is, wages exempt from Social Security tax*1110es. Stroup v. Barnhart, 327 F.3d 1258, 1259-60 (11th Cir. 2003), cert. denied, 540 U.S. 1074, 124 S.Ct. 935, 157 L.Ed.2d 745 (2003); Das v. Department of Health & Human Services, 17 F.3d 1250, 1253 (9th Cir. 1994). In that scenario, the WEP is invoked to recompute the PIA. 42 U.S.C. § 415(a)(7)(A) & (B).

The WEP was enacted in 1983 to prevent individuals who earned wages from both covered and non-covered employment from receiving an unwarranted windfall. See Fernandez v. Barnhart, 200 Fed.Appx. 325, 326-327 (5th Cir. 2006); Stroup, 327 F.3d at 1259-60; Das, 17 F.3d at 1253. Pursuant to the WEP, the PIA will be recomputed when the claimant is entitled to “a monthly periodic payment ... which is based in whole or in part upon his or her earnings for service which did not constitute ‘employment’ as defined in section 410 of this title for purposes of this subchapter.” 42 U.S.C. § 415(a)(7)(A). The regulations implementing the WEP provide further:

Noncovered employment includes employment outside the United States which is not covered under the United States Social Security system. Pensions from noncovered employment outside the United States include both pensions from social insurance systems that base benefits on earnings but not on residence or citizenship, and those from private employers.

20 C.F.R. § 404.213(a)(3).

Review of the Commissioner’s decision is limited to determining whether the ALJ applied the correct legal standard and whether the decision is supported by substantial evidence. See Hamilton v. Secretary of Health and Human Services, 961 F.2d 1495, 1497-98 (10th Cir. 1992); Brown v. Sullivan, 912 F.2d 1194, 1196 (10th Cir. 1990). Substantial evidence is evidence a reasonable mind would accept as adequate to support a conclusion. Brown, 912 F.2d at 1196. It requires more than a scintilla but less than a preponderance of the evidence. Hedstrom v. Sullivan, 783 F.Supp. 553, 556 (D.Colo. 1992). “Evidence is not substantial if it is overwhelmed by other evidence in the record or constitutes mere conclusion.” Musgrave v. Sullivan, 966 F.2d 1371, 1374 (10th Cir. 1992). Further, “if the ALJ failed to apply the correct legal test, there is a ground for reversal apart from a lack of substantial evidence.” Thompson v. Sullivan, 987 F.2d 1482, 1487 (10th Cir. 1993).

III. LEGAL ANALYSIS

In both this and his prior appeal of the administrative decision, plaintiff argues that the ALJ erred in concluding that the WEP applied to his Spanish pension benefits because his receipt of those benefits is based on his Spanish citizenship, not on his earnings.5 I remanded to the Commissioner to clarify whether plaintiffs non-covered benefits were based on earnings and to determine whether the Commissioner’s interpretation of the apposite statute and regulations in the POMS guidelines was supportable. Because the ALJ was unwilling or unable to address either of these issues, I reverse. However, because I find that the governing statute and regulations cannot be read to allow application of the WEP when receipt of non-*1111covered pension benefits are based on a claimant’s status as a citizen of a foreign country, I direct that plaintiff be awarded benefits calculated without application of the WEP.

As I noted in my previous opinion, the WEP applies to non-covered benefits that are “based in whole or in part upon ... earnings for service.” 42 U.S.C. § 415(a)(7)(A) (emphasis added). See also 20 C.F.R. § 404.213(a)(3) (noting that the WEP applies to “pensions from social insurance systems that base benefits on earnings but not on residence or citizenship”). Under the now-defunct SOVI, a worker was entitled to benefits if he had made at least 1,800 days of “contribution payments” into the program prior to January 1, 1967. Because “[njothing in the record suggested] that SOVI benefits are based in any way on plaintiffs earnings,” I remanded with directions for the ALJ to consider that question and further develop the record. (Tr. 255.)

That directive was largely ignored. Instead, it appears the ALJ relied principally on plaintiffs own, uncorroborated statement that his SOVI benefits were based on the number of hours he worked, not on his earnings (see Tr. 90, 325, 344-345, 226), and on the description of the SOVI as being a “Worker Retirement Scheme”6 (Tr. 226; see also Seguridad Social, Procedures and Formalities, Compulsory Elderly and Disability Insurance, Procedure (available at (http://www.seg-social.es/ Internet_6/Masinformacion/Tramitesy Gestiones/SeguroObligatoriode45964/index. htm?ssUserText=103257# 45966_6 (last accessed October 17, 2013)). This was hardly the in-depth inquiry that this court mandated on remand.7

Moreover, to the extent any of the evidence on which the ALJ relied was competent, plaintiffs status as a “worker” vel non merely begs the ultimate question *1112the court directed the ALJ to consider. Indeed, the ALJ utterly failed to undertake any substantive examination of the court’s additional mandate to determine whether the POMS, in equating earnings with work, was incongruent with the governing statute and regulations. Thus, the ALJ’s purported finding that “[t]he Social Security Act and applicable regulations do not require a foreign pension to be based on foreign earnings in order to be considered under the [WEP]” (Tr. 227), was nothing more than a mere conclusion, unsupported by substantial evidence.

As set forth in the statute, the PIA must be recomputed if the claimant is entitled to a non-covered benefit “based in whole or in part upon his or her earnings for service.” 42 U.S.C. § 415(a)(7)(A). As I noted in my previous opinion, the Commissioner’s decision to equate “earnings” with “work” is not clearly justified. Not all “work” one might undertake professionally is necessarily remunerative. Nothing in the ALJ’s opinion demonstrates that the equivalence of the two concepts in the POMS is appropriate. I conclude that it is not, and therefore that the POMS’s interpretation of the statute is arbitrary and capricious to the extent it equates “earnings” with “work.” Neikirk v. Massanari, 13 Fed.Appx. 847, 849-850 (10th Cir. 2001). Unless the claimant is receiving non-covered benefits based in whole or in part on his earnings — that is, money paid for services rendered — the WEP cannot be applied. Thus the ALJ’s determination that plaintiffs SOVI benefits are granted because of his status as a “worker,” as ill-supported factually as it is, ultimately is meaningless in any event.

Were these the only shortcomings of the Commissioner’s determination, I would feel constrained to remand yet again for further fact finding. Yet I perceive an even more fundamental issue that I find determinative of plaintiffs claim. The governing regulation provides that foreign pensions subject to the WEP “include both pensions from social insurance systems that base benefits on earnings but not on residence or citizenship, and those from private employers.” 20 C.F.R. § 404.213(a)(3) (emphasis added).8 Thus, the regulation expressly excludes from the WEP any pension from a social insurance system — such as the SOVI — that is based on residence or citizenship, regardless of whether it is also based on earnings.9

The Commissioner here already has accepted plaintiffs position that his SOVI benefits are based on his status as a citizen of Spain. (See Tr. 226 (“The claimant receives a monthly pension based on his work as a Spanish Citizen in Spain.”).) This determination is law of the case and thus binding on the Commissioner. See Nelson v. Astrue, 2009 WL 2338113 at *3-4 (D.Colo. July 27, 2009). Having thus conceded this determinative fact, the Com*1113missioner may not now apply the WEP to plaintiffs claim for benefits that he receives by virtue of his Spanish citizenship.

THEREFORE IT IS ORDERED as follows:

1. That the conclusion of the Commissioner through the Administrative Law Judge regarding plaintiffs benefits determination is REVERSED; and

2. That the Commissioner is DIRECTED to compute plaintiffs PIA, both past and future, without applying the Windfall Elimination Provision to account for the benefits he receives under the SOVI.

Dated October 18, 2013, at Denver, Colorado.