Assеrting diversity jurisdiction, the plaintiffs filed suit in federal court seeking damages under Texas law for the death of Louis Acridge in a Texas nursing home. The defendants Evangelical Lutheran Good Samaritan Society, Jerry Adams, Elaine Morrow, and Sherri Lunsford Harris appeal the denial of their motion for summary judgment on official immunity grounds. They also raise the issue of whether there is federal subject matter jurisdiction over the underlying proceeding. Because we conclude that complete diversity among the parties is lacking, we vacate the district court’s order denying summary judgment and remand with instructions to dismiss the case for lack of subject matter jurisdiction.
I. FACTS AND PROCEDURAL BACKGROUND
In 1968, Louis Acridge moved from Colorado to New Mexico, where he was employed as a sheriff and lived with his wife, Plaintiff-Appellee Mary Acridge. In 1996, Mary placed Louis in a retirement center in New Mexico as a result of a rapid deterioration in his mental status caused by Alzheimer’s dеmentia. Mary became dissatisfied with the treatment Louis was receiving and, in 1997, transferred him to the Farwell Convalescent Center in Far-well, Texas. 1 By that time, Louis was *447 completely unable to take care of himself, was disoriented as to time and place, had little memory, and was virtually unaware of his surroundings. When Mary moved Louis to Texas, she applied for and received Medicaid benefits from the Texas Department of Human Services. ■ The Texas Medicaid statute states:
Texas Residence Requirements
(a) General requirements. To be eligible for the Texas Title XIX Medical Assistance Program, an individual must be a resident of the State of Texas; that is, he must have established residence in Texas and he must intend to remain in Texas.
(b) Eligibility requirements for persons from another state. If a client is eligible for Title XIX benefits in another state and receives benefits in that state, he is not eligible for Title XIX benefits from the state of Texas.
40 Tex. Admin. Code. § 15.301 (West 2000).
After being at the Center for more than a year, Louis Acridge was placed in a room with Henry Plyler, another resident. Plyler had a history of abusive behavior toward past roommates. On June 23, 1999, staff members at the Center discovered Acridge in his bed, covered in blood; a ballpoint pen protruded from his right eye. An investigation revealed that Plyler had beaten Acridge on the head with a coffee mug and then stabbed him in the eye with a pen. The pen penetrated Acridge’s brain; he died eight hours later as a result of this wound.
In their First Amended Complaint filed June 7, 2001, the plaintiffs alleged that the defendants negligently failed to protect Louis Acridge from Plyler and that this failure was the proximate cause of Acridge’s death. The plaintiffs also claimed that the defendants were negligent in failing to warn Acridge and his family of the known risks that Plyler presented to his roommates. The defendants filed a motion to dismiss the suit on the grounds that no federal subject matter jurisdiction existed; the plaintiffs brought suit in federal court under diversity jurisdiction, but the defendants argued that complete diversity was lacking because both Louis Acridge and the defendants were Texas domiciliaries. The district court denied this motion without stated reasons.
The defendants also moved for summary judgment, claiming that each defendant was entitled to official immunity from suit. The defendants further asserted that Plyler’s unforeseeable criminal conduct was a superceding cause of Acridge’s death that absolved the defendants of liability for any alleged negligent conduct. The district court, again without stated reasons, denied the defendants’ motion for summary judgment.
The defendants now bring this interlocutory appeal of the district court’s denial of their summary judgment motion, arguing that the court should have granted their motion claiming official immunity. The defendants also urge us to examine whether there is diversity jurisdiction over these claims.
II. WHETHER DIVERSITY JURISDICTION EXISTS OVER THESE CLAIMS
Federal court jurisdiction here hinges on the domicile of Mary Acridge in her capacity as Independent Executrix of the Estate of Louis Acridge. Under 28 U.S.C. § 1332(c)(2) (2000), the legal representative of the estate of a decedent is deemed to be a citizen of the same state as the
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decedent for diversity purposes. Jurisdiction in this case rests on a single question: when Mary Acridge moved Louis Acridge into a Texas nursing home, did he become a Texas domiciliary? If he did, then complete diversity among the parties is lacking and the case cannot be heard in federal court.
Temple Drilling Co. v. La. Ins. Guar. Ass’n,
A. General Law of Domicile
A brief overview of the law of domicile will be helpful in our exploration of this question. First, while we may look to state law for guidance, the question of a person’s domicile is a matter of federal common law.
Coury v. Prot,
In determining whether a person has changed his domicile, courts have identified many factors which should be considered. Co
ury,
B. Law of Domicile for Incompetent Persons
Of course, the intent inquiry .becomes more problematic when the person in question has, like Louis Acridge, become mentally incompetent. Only minimal competency is required to choose a new domicile; even if the person in question has been adjudged incompetent by a court and is incapable of managing his own affairs, he can change his domicile so long as “he understands the nature and effect of his act.”
Juvelis by Juvelis v. Snider,
Where someone acting on an incompetent’s behalf moves the incompetent to another state, the question becomes whether *449 that move (coupled with the trappings of intent for the incompetent to remain in the new state indefinitely) should be permitted to change the incompetent’s domicile. There is a split in the circuits (and no Fifth Circuit precedent) on the question of whether someone acting on behalf of an incompetent can change the incompetent’s state of domicile.
In
Rishell v. Jane Phillips Episcopal Memorial Medical Center,
However, the Fourth Circuit takes the opposite position. In
Long v. Sasser,
The defendants urge us to adopt the position taken by the Seventh and Tenth Cirсuits (and rejected by the Fourth Circuit) that someone acting in the “best interests” of an incompetent may change the incompetent’s domicile. 3 After careful *450 ly considering the arguments set forth in each case, we agree with the Seventh and Tenth Circuits and hold that Mary Acridge had the authority to change the domicile of Louis Acridge so long as she was acting in his best interests.
An incompetent sits in an unenviable position in society, unable to fend for himself and completely dеpendent upon those closest to him. We agree with the Tenth Circuit: To hold that the person charged with making decisions on behalf of an incompetent lacks the authority to change the incompetent’s state of domicile in his best interests leaves the incompetent “in a never-ending limbo where the presumption against changing domicile becomes more important than the interests of the person the presumption was designed to protect.”
Rishell,
C. Analysis of Louis Acridge’s Domicile
Before turning to the “best interests” inquiry, we must first contend with arguments made by each party that Louis Acridge’s domicile has already been determined as a matter of law. The defendants rely on the fact that Mary Acridge applied for and received Medicaid benefits in the state of Texas. According to the Texas statute, only someone who has both “established residence in Texas” and has an “inten[t] to remain in Texas” is eligible for Medicaid benefits. 40 Tex. Admin. Code. § 15.301(a). The defendants conclude, therefore, that Louis Acridge’s domicile changed “through operation of law” when he applied for and received benefits that he could only be eligible for as a Texas domiciliary.
See, e.g., In re Gillmore’s Estate,
If we were to accept this argument, we would be expanding the general rule that a “domicile by operation of law” can be established only where “the law confers upon one party the control of the domicile of another because of the lack of competence of the latter.” Eugene F. Scales & Peter Hay, Conflict of Laws, § 4.42 (1st ed.1984). “Domicile by operation of law” typically *451 limits itself to domestic relations situations, such as the common law rule that a married wоman took the domicile of her husband or the rule that an unemancipated child has the domicile of his parents. 8 C.J.S. Domicile, § 9 (2002) (“Domicile by operation of law ... ordinarily results from legal domestic relations.”). Nothing in the Texas Medicaid statute purports to create a domicile based upon the act of applying for benefits — the statute merely limits eligibility to Texas domieiliaries.
However, while the defendants cannot argue that Louis Acridge’s domicile chаnged by operation of law, their reliance on Mary’s application for Texas Medicaid benefits for Louis as a factor favoring a finding of changed domicile is persuasive. According to the federal regulations governing state Medicaid eligibility:
(3) For any institutionalized individual who became incapable of indicating intent at or after age 21, the State of residence [for purposes of Medicaid eligibility] is the State in which the individual is physically present, except where another State makes a placement.
(4) For any other institutionalized individual, the State of residence is the State where the individual is living with the intention to remain there permanently or for an indefinite period.
42 C.F.R. § 435.403(i)(3)-(4) (2002). The definition of “State of residence” in subsection (4) mimics the generally understood definition of “domicile” — including the definition set forth in the Texas Medicaid statute.
See
Restatement (Second) of Conflict of Laws § 11 cmt. k (1988) (“Statutes in the United States rarely speak in terms of domicil but use ‘residence’ instead. Residence is an ambiguous word whose meaning in a legal phrase must be determined in each case. Frequently it is used in a sense equivalent to domicil.”);
see also Martinez v. Bynum,
However, we decline to accept the defendants’ related argument that, beсause Louis Aeridge was a Texas domiciliary for purposes of Medicaid law, he must also be a Texas domiciliary for purposes of determining diversity jurisdiction. The general rule is that “[a] person has only one domicile at a particular time.”
Knapp v. State Farm Ins.,
*452 The plaintiffs argue that this court must find that Louis Acridge is a New Mexico domiciliary because a New Mexico state court, in probating Louis Acridge’s will, found that it had venue over the case “because the Decedent’s domicile at the time of death was Clovis, Curry County, New Mexico.” The plaintiffs seek to rely upon the principles of collаteral estoppel (combined with the Full Faith and Credit Clause) to conclude that the defendants are bound by that determination of Louis Acridge’s domicile and may not relitigate the question in these proceedings.
Where a party seeks to use an issue decided in state court to preclude relitigation in federal court, the federal court must, under the full faith and credit doctrine, give that issue the same preclusive effect that the courts of the state which decided the issue would give it. 28 U.S.C. § 1738 (2000);
see also Matsushita Elec. Indus. Co. v. Epstein,
While this suit certainly presents a different cause of action than the probating of Acridge’s estate, the plaintiffs cannot satisfy the remainder of the test. There is no evidence that the issue of Louis Acridge’s domicile was ever fully litigated in state court; all we have is the bare statement by the court that Acridge was a New Mexico domiciliary. Additionally, whether or not Louis Acridge was a New Mexico domiciliary was not necessary to the determination that his estate was eligible for probate in New Mexico; according to state law, the estate of a non-domiciliary can be probated in New Mexico “in any county where property of the decedent was located at the time of his death.” N.M. Stat. Ann. § 45-3-201 (Mi-chie 1978). Thus, even if the court found that Louis Acridge was a Texas domiciliary, it still could have permitted probate of the estate оn the grounds that Acridge owned property located in New Mexico (as, in fact, he did). Finally, none of the defendants was a party to the probate proceedings, nor were his or her interests represented by someone who was a party to those proceedings. As such, none of the defendants had a full and fair opportunity to litigate the question of Louis Acridge’s domicile. Because the plaintiffs cannot satisfy the requirements for collаteral es-toppel under New Mexico law, this court is not required to give preclusive effect to the determination by the New Mexico state court that Louis Acridge was domiciled in that state.
Having disposed of these arguments, we can now turn to the “best interests” analysis to determine Louis Acridge’s domicile, keeping in mind that the burden of proof concerning change of domicile rests with the party seeking to establish that domicile has changed.
Juvelis,
Since domicile is a fact-bound question, we would ordinarily remand for the district court to make the necessary determination. This record, however, per *453 mits of only one conclusion. Mary Acridge admits that she removed her husband from the Buena Vista Retirement Center in Clovis, New Mexico because she was “dissatisfied with the care that Louis was receiving.” There is no evidence in the record that Mary Acridge gained any personal benefit from having her husband moved to another state. Louis Acridge remained in the Farwell Convalescent Center for more than two years before being stabbed by Henry Plyler; there is no evidence in the record that, at any point during his stay, Mary Acridge had grown unhappy with the care her husband was reсeiving or considered relocating him to a third retirement home in another state. In short, on the evidence in the record, Mary Acridge moved her husband from New Mexico to Texas in order to obtain, in his best interests, the highest possible standard of care for the remainder of his life.
Because Mary Acridge was acting in the best interests of her husband when she moved him to the Farwell Convalescent Center, it is clear that, for purposes of diversity jurisdiction, Louis Acridge was a Texas domiciliary at the time of his death. As such, complete diversity among the parties in this action is lacking. There is no federal subject matter jurisdiction over this case. 4
III. CONCLUSION
We VACATE the district court’s order denying the defendants’ motion for summary judgment and REMAND the case with instructions to dismiss for lack of subject matter jurisdiction. Costs shall be borne by the plaintiffs.
Notes
. Defendant Evangelical Lutheran Good Samaritan Society ("Good Samaritan”) operated the Farwell Convalescent Center. Defendant Jerry Adams was an administrator at the Center; defendants Elaine Morrow and Sherri Lunsford Harris were the directors of nurs *447 ing at the Center during times relevant to this case.
. Mary Acridge is a Colorado domiciliary and her son, also a plaintiff, is a New Mexico domiciliary. The individual defendants are all Texas domiciliarles; Good Samaritan is a North Dakota corporation.
. Each of the prior cases dealing with this question has involved a court-appointed guardian with recognizеd legal capacity to act on behalf of the incompetent; the record in this case does not reveal that Mary Acridge took the step of having herself appointed her
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husband's legal guardian. However, neither party argued, here or in the district court, that
Rishell, Long,
or
Dakuras
should be distinguishable on that basis; as such, we will treat the arguments to that effect as having been waived.
Trevino v. Johnson,
. Because we conclude that federal jurisdiction over these claims is lacking, we decline to reach the defendants' additional contentions regarding the district court’s denial of their motion for summary judgment on official immunity grounds.
