T1 The State of Oklahoma ex rel. Oklahoma Department of Human Services (OKDHS), Howard Hendrick, Director of OKDHS, Oklahoma Health Care Authority (OHCA),1 Mike Fogarty, Director of OHCA, and Gerry Moore, individually, (collectively, the State) appeal the trial court's September 18, 2008, Order Granting Plaintiffs' Motion for Partial Summary Judgment in which the trial court found Dale McAlary and Pearl McAlary, husband and wife (MeAlarys), were improperly denied Medicaid benefits and issued an injunction preventing the State from denying Medicaid benefits to McAlarys and those similarly situated.2 We reverse.
FACTS AND PROCEDURAL BACKGROUND
12 On January 2, 2008, McAlarys moved from an assisted living facility to the Vici Nursing Home in Vici, Oklahoma. On January 8, 2008, McAlarys' daughter, Sandra Elliott (Daughter), created the McAlary Family Trust (the Trust)3 McAlarys are beneficiaries of the Trust during their lifetimes, and when they are both deceased, the remainder will be evenly divided among their three children, including Daughter. Daughter, as trustee of the Trust, is authorized to use the entire corpus and income at any time for the benefit of her parents during their lifetimes. As stated by Daughter in Article III of the Trust:
It is my desire, by this instrument, to create a trust in accordance with the laws of the State of Oklahoma whereby property placed in this trust shall be managed for the benefit of Beneficiaries during Benefi-claries' lifetimes and distributed to the remainder beneficiaries named herein upon Beneficiaries' deaths. My primary pur*402pose of this trust is to provide funds to be spent on behalf of the Beneficiaries. It is my intention to benefit the Beneficiaries to the fullest extent possible rather than the remainder beneficiaries.4
McAlarys, in their brief filed on January 20, 2009, state that Daughter did not establish the Trust at the direction or upon the request of McAlarys; instead, she established the Trust upon her own volition and in her individual capacity because she wanted to do some planning to benefit her parents.5 However, at the administrative level it was found that Daughter established the Trust in her capacity as attorney in fact for McAlarys.6
18 On January 21, 2008, Daughter transferred $178,080 of McAlarys' money and property to the Trust. In return, MceAlarys received a promissory note signed by Daughter in her capacity as trustee. The promissory note stated that the $178,030, plus four percent interest, would be repaid in six yearly installments of $29,671.76, beginning on January 8, 2009. However, the promissory note was unsecured and contained the following provision:
This is a non-recourse note. Notwithstanding anything to the contrary in this note, the Borrower shall not have any personal Hability for payment of this note or any sums due hereunder, and the Lender and all subsequent holders shall look solely to the payments hereunder for payment and satisfaction of all sums due under this note.7
14 On January 22, 2008, McAlarys filed a Medicaid application with OKDHS. In a letter dated March 18, 2008, OKDHS denied both applications because it found McAlarys had "countable resources in excess of $2,000 on the date of application and for the 90 days preceding."8 On March 19, 2008, McAlarys filed a Request for a Fair Hearing.
T5 A hearing was held on June 4, 2008.9 McAlarys argued at the hearing that their promissory note was unmarketable and had no value.10 On June 19, 2008, the OKDHS Appeals Committee issued a decision in which it found OKDHS acted correctly in denying McAlarys' Medicaid applications because they had countable resources worth $178,080. The Appeals Committee found, in the alternative, that if the $178,080 in the Trust was not a countable resource of McA-larys, then when McAlarys proved their promissory note had no value, they proved, by extension, that they had made a transfer of $178,030 without receipt of fair market value.
T6 On June 20, 2008, pursuant to 56 0.8. 2001 § 168(C), McAlarys requested that Howard Hendrick, Director of OKDHS (Director Hendrick), review the hearing decision. On July 18, 2008, Director Hendrick issued his decision. Director Hendrick concluded that the Trust was an available resource to McAlarys and the promissory note had no value. Director Hendrick stated, in part, that:
[Daughter] is authorized to exhaust the Trust's corpus and income for the benefit of [MecAlarys] during their lives. According to [Oklahoma Administrative Code (OAC)] 817:35-5-41.6(5)(C), whether the Trust is revocable or irrevocable, the entire $178,030 corpus is considered an available resource to them. According to OAC 317:85-19-20(2)(B), each of the McAlarys is allocated $89,015, half of the $178,030. This exceeds the $2,000 Medicaid resource limit. After Mr. McAlary died, all of the corpus became [Pearl] MeAlary's.
Director Hendrick also stated:
If the Trust is a countable resource and the [promissory note] is worthless, then the [promissory note] should be considered a nullity because it has no practical effect. The McAlarys will benefit from the Trust either by payments to them directly, or for their benefit as Trust beneficiaries, or they *403will benefit from the Trust when [Daughter] makes payments of corpus and income to them as payments on the [promissory note].
Director Hendrick concluded:
I find that OKDHS acted correctly in denying Mr. and Mrs. MeAlary's Medicaid applications. The denial can be made on four separate grounds, as described above. Based on my conclusion that the Trust is an available resource and that the [promissory note] has no value, the Trust corpus constituted a countable resource to Mr. and Mrs. McAlary until his death and to Mrs. McAlary alone thereafter.11
Director Hendrick's decision was the final decision at the administrative level. See 56 ©.98.2001 § 168(C).
T7 Pursuant to 56 O.8.2001 § 168(D), McAlarys appealed the OKDHS decision to the District Court of Dewey County by filing their Petition on March 25, 2008. In the trial court's September 18, 2008, Order Granting Plaintiffs' Motion for Partial Summary Judgment, the trial court found McAlarys were improperly denied Medicaid benefits and issued an injunction preventing the State from denying Medicaid benefits to MecAlarys and those similarly situated. From this Order of the trial court, the State appeals.12
STANDARD OF REVIEW
8 Onee an administrative agency order is before us, the Oklahoma Administrative Procedures Act (OAPA), 75 0.8.2001 and Supp. 2005 §§ 250-827, governs our review. Pharmcare Oklahoma, Inc. v. State of Oklahoma Health Care Authority, 2007 OK CIV APP 5, 152 P.3d 267.13 Under the OAPA, the trial court, the Oklahoma Court of Civil Appeals, and the Oklahoma Supreme Court apply the same standard of review to the administrative record. Id.; City of Tulsa v. State. of Oklahoma ex rel. Public Employees Relations Board, 1998 OK 92, 967 P.2d 1214.14
19 Generally, an administrative decision should be affirmed if it is a valid order and the administrative proceedings are free from prejudicial error. 75 0.8.2001 § 322(8).15 An administrative order is subject to reversal, however, if an appealing party's substantial rights are prejudiced because the agency's decision is entered in excess of statutory authority or jurisdiction, or an order is entered based on an error of law. 75 0.8.2001 § 322(1)(b) and (d). Reversal is also appropriate if the agency's findings are clearly erroneous in view of the "reliable, material, probative and substantial competent evidence" in the record. 75 0.8.2001 § 322(1)(e). As to factual questions, neither a trial court nor this Court is entitled to substitute its judgment for that of the agency as to the weight of the evidence. Id.; Board of Examiners of Veterinary Medicine v. Mohr, 1971 OK 64, 485 P.2d 235.
*404T 10 We must accord great weight to the expertise of an administrative agency. City of Hugo v. State of Oklahoma ex rel. Public Employees Relations Board, 1994 OK 134, 886 P.2d 485. We may not substitute our judgment for that of the agency, and this holds true particularly in the area of the agency's expertise. City of Midwest City v. Public Employees Relations Board, 2003 OK CIV APP 36, 69 P.3d 1218.
ANALYSIS
1 11 The State argues that the $178,030 of McAlarys' money and property placed by Daughter into the Trust is an available resource to McAlarys, placing them well above the relevant resource limit and thereby disqualifying them from Medicaid eligibility in Oklahoma. This is consistent with the conclusion reached at the administrative level. In opposition, MceAlarys argue that the $178,030 located in the Trust is not an available resource to them.16
McAlarys' Attempt to Supplement the Record
112 McAlarys argue they are entitled to introduce additional evidence on appellate review in the form of an affidavit attached to their brief because the State allegedly did not raise the issue of whether the Trust assets are a countable (Le., "available") resource during the entire administrative process. In support, McAlarys cite to 75 0.9$.2001 § 821, which states:
The review shall be conducted by the court without a jury and shall be confined to the record, except that in cases of alleged irregularities in procedure before the agency, not shown in the record, testimony thereon may be taken in the court. The court, upon request, shall hear oral argument and receive written briefs.
McAlarys' attempt to supplement the record before this Court is not supported by § 821. Section 321 applies to the trial court-hence the reference to "a jury" and to "testimony." Absent a statute requiring otherwise, this Court will not consider as part of an appellate record any instrument or material which has not been incorporated into the assembled record by a certificate of the clerk of the trial court. City of Lawton v. International Union of Police Associations, Local 24, 2002 OK 1, ¶ 7 n. 15, 41 P.3d 371, 375 n. 15. (Citations omitted.) A deficient record may not be supplemented by material physically attached to a party's appellate brief. Id. at n. 16.
113 Furthermore, the issue McAlarys allege was never raised by the State-whether the Trust assets are an available resource-was present from the first stage of the administrative process when OKDHS denied McAlarys' applications for this very reason.17 In addition, it was present at the final stage of the administrative process because it received extensive treatment in the July 18, 2008, decision by Director Hendrick. In that decision,18 Director Hendrick states:
On July 10, 2008, you, as counsel for the McAlarys, were contacted by an OKDHS employee who was working with me on this decision. You were informed that the Trust was going to be treated as an available resource in this decision ... [and] you were given excerpts dealing with the Trust from a draft of this decision and asked if you wished to submit comments. You declined.
"Parties to an action on appeal are not permitted to secure a reversal of a judgment upon error which they have invited, acquiesced or tacitly conceded in...." Samedan Oil Corporation v. Corporation Commission of the State of Oklahoma, 1988 OK 56, ¶ 7, 755 P.2d 664, 668. "[TThis is a well-settled rule which emanates from the very heart of the purpose served by an appeal." Id. McAlarys waived appellate relief as to this alleged error of their own accord.19
*405The Trust as an Available Resource to McAlarys
T14 Prior to turning to the specific Oklahoma Administrative Code (OAC) see-tions which govern Medicaid eligibility in Oklahoma, it is important first to set forth the purpose and objective of the federal Medicaid Act. While a state is not obliged to participate in a Medicaid program, if it does participate, it must operate its program in compliance with the federal Medicaid Act. Pharmcare Oklahoma, Inc. v. State of Oklahoma Health Care Authority, 2007 OK CIV APP 5, 152 P.3d 267. "States do, however, have broad discretion to adopt standards for determining the extent of medical assistance, with the Act requiring only that the standards be reasonable and consistent with the objectives of the Medicaid Act." Id. at 112 (citing 42 U.S.C. § 1896a(a)(17)).20
T 15 "Congress established the Medicaid program in 1965 as Title XIX of the Social Security Act ... to provide federal financial assistance to States that choose to reimburse certain medical costs incurred by the poor." Blum v. Yaretsky, 457 U.S. 991, 993-994, 102 S.Ct 2777, 73 LEd.2d 534 (1982). (Citation omitted.) Medicaid was created by Congress "[flor the purpose of enabling each State, as far as practicable under the conditions in such State, to furnish (1) medical assistance on behalf of families with dependent children and of aged, blind, or disabled individuals, whose income and resources are insufficient to meet the costs of mecessary medical services ...." 42 U.S.C. § 1396. (Emphasis added.) Hence, Medicaid is a welfare program and its fundamental objective is to provide medical services for the poor. See Zelman v. Simmons-Harrig, 536 U.S. 639, 667, 122 S.Ct. 2460, 153 L.Ed.2d 604 (2002) (O'Connor concurring); Soskin v. Reinertson, 353 F.3d 1242 (10th Cir.2004). "[Medicaid] is a cooperative program of the state and federal governments that provides medical assistance for the poor." Pharmcare Oklahoma, Inc., at ¶ 12, 152 P.3d at 269. (Emphasis added.) Therefore, the specific OAC sections which we will apply in determining whether McAlarys are eligible for Medicaid payments in Oklahoma must be reasonable and consistent with the fundamental objective of providing medical assistance for the poor.
€ 16 Oklahoma's Medicaid program is set forth in Title 817 of the OAC, 817:35-1-317:35-28. In order for an individual to receive payment for medical services under Oklahoma's Medicaid program, he or she must meet the relevant eligibility requirements found therein. OAC 817:35-1-1.
T17 As determined at the administrative level pursuant to OAC 817:85-19-21(2)(B), McAlarys' individual resource limit is $2,000.21" If McAlarys' individual resources exeeed this amount, then they are ineligible for Medicaid payments. OAC 317:85-19-21(2) explains how the resources of a couple such as the McAlarys are to be allocated. In pertinent part, § 317:35-19-21(2) states that "resources are determined for each individual as the amount owned by each individual plus one-half of the jointly owned resources of the couple." If it is determined that the *406Trust is an available resource to McAlarys, then each spouse will own $89,015, or one-half, of this joint resource, placing each of them $87,015 above the $2,000 resource limit and thereby disqualifying them from eligibility for Medicaid payments. This resource limit is reasonable and consistent with the fundamental objective of Medicaid.
1 18 Determination of whether the Trust is an available resource to McAlarys begins with determining whether McAlarys "established" the Trust. OAC 817:85-5-41.6(5), which applies to trust accounts established after August 10, 1998, states, in part:
(A) ... An individual is considered to have established a trust if assets of the individual were used to form all or part of the principal of the trust and if the trust was established other than by will and by any of the following individuals:
() the individual;
(ii) the individual's spouse;
(iii) a person, including a court or administrative body, with legal authority to act in place of or on behalf of the individual or the individual's spouse; or
(iv) a person, including a court or administrative body, acting at the direction or upon the request of the individual or the individual's spouse.
(B) Where trust principal includes assets of an individual described in this subpara-graph and assets of any other person(s), the provisions of this subparagraph apply to the portion of the trust attributable to the assets of the individual. This subpara-graph applies without regard to the purposes for which the trust is established, whether the trustees have or exercise any discretion under the trust, and restrictions on when or whether distributions may be made from the trust, or any restrictions on the use of the distribution from the trust.
The above OAC language does not require that the individual or the individual's spouse establish the trust. Rather, the OAC states that even if a trust is established by a person with legal authority to act in place of or on behalf of the individual, or even if a trust is established by a person acting at the direction or upon the request of the individual, the individual will be considered to have established the trust.
19 The Trust was established by Daughter. Evidence that Daughter acted on behalf of McAlarys as their attorney in fact includes Daughter's statement in Article III of the Trust that her primary purpose in establishing the Trust was to provide funds to be spent on behalf of McAlarys, and it was her intention to benefit McAlarys to the fullest extent possible rather than the reraainder beneficiaries. Additionally, within just two weeks of establishing the Trust, it was funded by $178,030 of McAlarys' own money and property (on January 21, 2008). Furthermore, just one day after the $178,080 was placed in the Trust (on January 22, 2008), McAlarys applied for Medicaid. The administrative agency found that when Daughter established the Trust, she was acting on behalf of McAlarys as their attorney in fact. In view of the "reliable, material, probative and substantial competent evidence" in the record, this finding is not clearly erroneous. 75 0.8.2001 § 822(1)(e). Therefore, since the record supports the finding that Daughter acted on behalf of McAlarys, we must consider McAlarys to have established the Trust. OAC 317:835-5-41.6(5)22 We must accord *407great deference to the factual findings and conclusions of an administrative agency. 75 O.S.2001 $ 322(1)(e); Board of Examiners of Veterimary Medicine v. Mohr, 1971 OK 64, 485 P.2d 235. Even if competent evidence exists in opposition to a factual finding, this Court is not entitled to substitute its judgment for that of the ageney as to the weight of the evidence. Id. Moreover, we must accord great weight to the expertise of an administrative agency. City of Hugo v. State of Oklahoma ex rel. Public Employees Relations Board, 1994 OK 134, 886 P.2d 485.
120 Having determined that MceAlarys must be considered to have established the Trust, we must now focus on the Trust itself to determine if it was an "available resource" to McAlarys. OAC 317:35-5-41.6(5) states, in pertinent part:
(C) There are two types of trusts, revocable trusts and irrevocable trusts.
(1) In the case of a revocable trust, the principal is considered an available resource to the individual. Home property in a revocable trust under the direct control of the individual, spouse or legal representative retains the exemption as outlined in OAC 317:35-5-41.8(a)(@). Payments from the trust to or for the benefit of the individual are considered income of the individual. Other payments from the trust are considered assets disposed of by the individual for purposes of the transfer of assets rule and are subject to the 60 months look back period.
(i) In the case of an irrevocable trust, if there are any cireumstances under which payments from the trust could be made to or for the benefit of the individual, the portion of the principal of the trust, or the income on the principal, from which payment to the individual could be made is considered available resources. Payments from the principal or income of the trust is considered income of the individual. Payments for any other purpose are considered a transfer of assets by the individual and are subject to the 60 months look back period. Any portion of the trust from which, or any income on the principal from which no payment could under any cireumstances be made to the individual is considered as of the date of establishment of the trust (or if later, the date on which payment to the individual was foreclosed) to be assets disposed [of] by the individual for purposes of the asset transfer rules and are subject to the 60 months look back period.
Under this language it is unnecessary to determine whether the Trust is revocable or irrevocable. Either way, the Trust is an available resource to McAlarys. If the Trust is a revocable trust, then the $178,080 simply "is considered an available resource to [McA-larys]." If the Trust is an irrevocable trust, then the $178,030 is also an available resource to McAlarys because there are circumstances under which payment of all of the $178,080 from the Trust could be made to or for the benefit of McAlarys. Once again, as stated by Daughter in Article III of the Trust:
It is my desire, by this instrument, to create a trust ... whereby property placed in this trust shall be managed for the benefit of [McAlarys] during [MeAlarys'] lifetimes and distributed to the remainder beneficiaries named herein upon [MecAlar-ys'] deaths. My primary purpose of this trust is to provide funds to be spent on behalf of [MeAlarys]. It is my intention to benefit [MceAlarys] to the fullest extent possible rather than the remainder benefi-claries.
Therefore, the $178,030 in the Trust is an available resource to McAlarys. As stated above, this places them well above the applicable Medicaid resource limit, thereby disqualifying them from Medicaid eligibility.
121 The specific sections of the OAC requiring this result are reasonable and consistent with the fundamental objective of Medicaid to serve the poor. Furthermore, these specific sections follow the mandatory requirements set forth in 42 U.S.C. § 18396p(d). *408"The legislative purpose behind § 1896 is clear from the language of the statute. Congress required that states generally count trust assets ... for purposes of determining Medicaid eligibility...." Keith v. Rizzuto, 212 F.3d 1190, 1193 (10th Cir.2000).23 The "available asset rule," as set forth in § 1896, "is consistent with Congress's intent to strictly limit Medicaid payments to the "truly needy.'" Gayan v. Illinois Dept. of Human Services, 342 Ill.App.3d 1035, 277 Ill.Dec. 571, 796 N.E.2d 657, 661 (2003) (citing Cherry by Cherry v. Sullivan, 30 F.3d 73, 75 (7th Cir.1994)).24
122 We must "affirm the order and decision of the agency, if it is found to be valid and the proceedings are free from prejudicial error...." 75 0.8.2001 § 3228). Finding no prejudicial error at the administrative level, we reverse the Order of the trial court.25
CONCLUSION
23 For the reasons set forth, we reverse the Order of the trial court and reinstate the administrative decision "that OKDHS acted correctly in denying [MceAlarys'] Medicaid applications." If the OHCA determines an overpayment has been made as a result of the injunction issued by the trial court, it may institute a recoupment procedure pursuant to OAC 317:35-13-5(b)(1).26
1 24 REVERSED.
WISEMAN, V.C.J., and GOODMAN, J., concur.