The administrator of an estate is a legal term referring to a person appointed by a court to administer the estate of a deceased person who left no will. Where a person dies intestate, i.e., without a will, the court may appoint a person to settle their debts, pay any necessary taxes and funeral expenses, and distribute the remainder according to the procedure set down by law. Such a person is known as the administrator of the estate and will enjoy similar powers to those of an executor under a will.

Once an individual dies, their estate must pass through the estate process. This process, conducted in a state or local probate court, involves the disposition of the decedent's estate either by will or intestacy. Often, to facilitate this process, the Court will appoint an Administrator of the Estate. The Court tasks this administrator with managing the decedent's estate—which includes collecting the decedent's assets, paying off all necessary debts, and distributing the remains to the decedent's heirs. However, these Administrators do not hold unlimited responsibilities but rather derive all of their power solely from the probate court. Thus, once the Administrator properly disposes of the estate, their role ceases to exist.

A court will appoint an estate administrator only when either the decedent died without a will, the decedent failed to name an executor in their will, or a named executor is unable or unwilling to perform their duties. Generally, while any person may serve as an Administrator of an Estate, probate courts are limited by state statute or common law as to whom they may select. Some of the most common restrictions will be provided below. So although the information below provides general overview of general formalities, it's best to consult a particular state's relevant statutes for further guidance.

In some states, statute requires probate courts to appoint an administrator from a selected "preferred party list." A preferred party could range from the decedent's surviving widow to a surviving cousin. To provide an example, see the District of Columbia's preferred party statute: "If the intestate leave[s] a widow or surviving husband and a child or children, administration, subject to the discretion of the court, should be granted either to the widow or surviving husband or to the child, or one or more of the children qualified to act as Administrator." While some states allow probate courts to stray from this preferred list, most are required to pick from the restricted pool unless all preferred parties waive the right to be administrator.

Before an Administrator may be appointed, they must first be determined competent. This competency, no different from competency in other legal matters, derived from the common law's requirement that administrators be free from any mental condition that would impair their ability to serve the best interests of the estate. Today, almost all states adopt this common law standard with some extending its boundaries to include physical impairments as well. It is important to note however that a Court cannot base their competency determination on general factors such as age or mobility. Rather, the Court or a petition party must establish specific mental or physical impairments that will almost certainly impair the administrators judgment (things such as dementia, cerebral palsy, or a traumatic brain injury).

Probate courts may refuse to appoint individuals as administrators if they possess an adverse interest to the estate. The exact definition of an "adverse interest" falls entirely on a strict case-by-case factual inquiry. For instance, generally, the fact that an individual also serves as a beneficiary of an estate does not bar them from serving as an administrator. Instead, courts are required to assess all circumstances regarding an administrator's adverse interest and determine whether these interests are egregious enough to require disqualification. While not representative of a de facto rule, many state courts found the following circumstances egregiously adverse: Parties who actively contest a will cannot serve as administrators; Parties asserting ownership of real or personal property cannot serve as administrators; Parties involved in other litigation regarding the decedent's estate cannot serve as administrators.

While courts may be disposed to approve preferred parties of the estate, they are generally not limited from appointing "strangers" of the estate. Courts generally define "stranger" of an estate as an individual unrelated, by either blood or marriage, to the decedent and one without any interest in the decedent's estate. Judges and scholars view these "strangers" as more desirable administrators because they, unlike preferred parties, will not clouded in their decision-making by any personal interest. Regardless, outside a statutory preferred-party requirement, probate courts are free to appoint any "stranger" as estate administrators

While this may not demonstrate an exhaustive list of all statutory limitations on the appointment of administrators, they represent a thread of common factors probate courts must review in their appointment decisions.