The Court in Marriage of LaMusga clarified the parents’ respective burdens when the custodial parent seeks to move and the noncustodial parent opposes the move. Marriage of LaMusga (2004) 32 Cal.4th 1072. A parent entitled to custody of a child has a right to change the residence of the child, subject to the power of the Court to restrain a removal that would prejudice the rights or welfare of the child. Cal. Fam. §7501(a); Marriage of Burgess (1996) 13 Cal.4th 25, 32. When the move-away contest comes after a final (“permanent”) custody order is in place, the noncustodial parent has the substantial burden of demonstrating a material change of circumstances of a kind that renders it “essential or expedient” for the welfare of the children that custody be modified. Id. at 38. The noncustodial parent bears the initial burden of showing that the proposed relocation of the child’s residence would cause detriment to the child, requiring a reevaluation of the child’s custody. Marriage of LaMusga, 32 Cal.4th at 1078. The court in LaMusga did not describe the degree of detriment which must be shown, although it has since indicated that the noncustodial parent must make a substantial showing. In re Marriage of Brown and Yana (2006) 37 Cal.4th 947, 960.

If the noncustodial parent carries that threshold burden, the Court must perform the delicate and difficult task of determining whether a change in custody is in the best interests of the children. Marriage of LaMusga, 32 Cal.4th at 1078. Neither parent is assigned the burden of persuasion to justify his choice of residence, “as the statutory policy promoting ‘frequent and continuing contact with both parents’ (Family Code Section 3020) does not limit the ‘trial court’s broad discretion to determine in light of all the circumstances, what custody arrangement serves the “best interest” of minor children.’ [Citation]” Marriage of LaMusga, 32 Cal.4th at 1088.

In Marriage of LaMusga, the mother with primary physical custody of two children filed a motion on February 13, 2001 to modify visitation order to permit her to relocate with children from California to Ohio after a Judgment was entered dissolving the marriage as of December 31, 1997. The Superior Court of Contra Costa County ordered that father would gain physical custody of the children at least during the school year if mother relocated. Mother appealed and the Court of Appeal reversed and remanded.

The Supreme Court granted review and the Judgment of the Court of Appeal was reversed and the matter was remanded to the lower court with directions to affirm the Superior Court’s postjudgment order transferring custody of the children to the father if the mother moves to Ohio.

The Supreme Court held among the factors that the court ordinarily should consider when deciding whether to modify a custody order in light of the custodial parent’s proposal to change the residence of the child are the following:

• the children’s interest in stability and continuity in the custodial arrangement;
• the distance of the move; the age of the children;
• the children’s relationship with both parents;
• the relationship between the parents including, but not limited to, their ability to communicate and cooperate effectively and their willingness to put the interests of the children above their individual interests;
• the wishes of the children if they are mature enough for such an inquiry to be appropriate;
• the reasons for the proposed move; and
• the extent to which the parents currently are sharing custody. Id at 1076.

In that case, the Supreme Court focused on the relationship between the boys and their father and that said relationship being lost if the children relocated 2000 miles away and that said relocation under those circumstances would be detrimental to the children’s welfare. Id at 1085.

The trial court may properly conclude that a history of animosity between the parents and more significantly of the custodial parent’s consistent attempts to limit contact between the children and the noncustodial parent indicates that the proposed move would be detrimental to the children. Id at 1095. In that case, the trial court concluded that the mother’s (custodial) past conduct made it unlikely that she would facilitate the difficult task of maintaining the father’s (noncustodial) long-distance relationship with the boys.