The purpose of this article is to review issues of child custody decision making within the context of current divorce law in the United States. The review is divided into seven sections. In the introduction, the locus of custody standards within state law is noted, with a brief review of national and international influences. In section two, frequently used terms are defined to give clearer meaning to the discussion than follows. In sections three through seven, we reexamine four central issues in custody law identified by Mnookin (1975) and update each issue with recent literature. The rights and responsibilities of noncustodial parents, grandparents, and stepparents are briefly described within this discussion of central legal custody issues. We conclude by suggesting the need for intermediate decision rules to improve the use of the best interests of the child (BIOC) standard in child custody decision making. Before beginning, it is important to recognize what is not covered in this review. Laws addressing grounds and financial aspects of divorce (i.e., spousal support, property divisions, child support) are not covered in this article because they are reviewed in a recent article by Buehler (1995). Mediation is not addressed in any detail because the topic is covered by Emery in this special issue. Finally, other areas of custody law, such as juvenile court child-neglect law, are not addressed because the focus of at this article is on divorce law. STATES: THE LOCUS OF DIVORCE CUSTODY LAW Historically, most divorce law has been established through state statutes, and reviewed and tested through the appellate courts at the state level (Buehler, 1995; Fine & Fine, 1994). As a result, there is a fair amount of variability in laws from state to state. However, it is possible to examine national trends by using a wide lens and focusing on general patterns rather than unique state variations. During the process of identifying and elaborating these general patterns, we began to recognize a subtle shift in the locus of divorce custody decision making. Although the U.S. Congress has increased federal involvement in regulating the financial aspects of divorce decision making (e.g., the child support regulations entailed in the 1988 Family Support Act; Buehler, 1995; Elrod, 1994), national activity related to child custody regulation has been minimal. Instead, discussions of divorce-related child custody issues have focused on deregulation. Most states have stressed that parents should be encouraged to arrive at a custody decisions privately (as long as children are not in harm's way) and that, when disputes occur, they should be resolved on a case-by-case basis using the BIOC standard (see Appendix; Atkinson, 1984). This standard will be discussed in detail in the next section of the article, but it is important to note that the use of this standard allows for individualized decision making by the courts and considerable discretion by judges (Mnookin, Maccoby, Albiston, & Depner, 1990). Additional evidence of the trend toward n privatizing custody decision making is the increased interest in moving the process from the courtroom to the mediation office (Emery & Wyer, 1987). Mediation is being considered by many as a viable alternative forum for custody decision making (Emery, 1994), and may replace some of the states' active involvement in the future. Before considering legal trends in state divorce custody decision making, several federal and international actions need mention. First, federal courts typically do not claim jurisdiction over matters of divorce, alimony, or child custody (Elrod, 1994; Federal Procedure, 1:286, 1981). Implications of this limitation are that custody decisions are not appealed to the U.S. Supreme Court, and general national trends are discernible primarily at the state level of appeal through an examination of case law. Second, in 1970, the National Conference of Commissioners on Uniform State Laws adopted the Uniform Marriage and Divorce Act (UMDA; Editors of The Family Law Reporter, 1974). …