25-4A-11. Plaintiff in custody action to file and serve guidelines -- Guidelines as court order -- Custody of minors. Upon the filing of a summons and complaint for divorce or separate maintenance or any other custody action or proceeding, the plaintiff shall also file and serve upon the defendant a copy of the standard guidelines. The standard guidelines attached to the summons shall become an order of the court upon fulfillment of the requirements of service. Any minor child of the marriage shall remain in the custody of the parent who has been the primary caregiver for the minor child for the majority of time in the thirty days preceding the filing of the summons and complaint, unless the parties agree otherwise. The standard guidelines shall apply and continue in effect, unless the parties agree, or the court orders otherwise. Imposition of the standard guidelines creates no presumption as to who shall be awarded custody at any hearing.

25-5-8. Father's rights not superior to mother's while separated. The husband and father, as such, has no rights superior to those of the wife and mother in regard to the care, custody, education, and control of the children of the marriage, while such husband and wife live separate and apart from each other.

25-5-7.1. Order for joint legal custody -- Factors for court's consideration. In any custody dispute between parents, the court may order joint legal custody so that both parents retain full parental rights and responsibilities with respect to their child and so that both parents must confer on major decisions affecting the welfare of the child. In ordering joint legal custody, the court may consider the expressed desires of the parents and may grant to one party the ultimate responsibility over specific aspects of the child's welfare or may divide those aspects between the parties based on the best interest of the child. If it appears to the court to be in the best interest of the child, the court may order, or the parties may agree, how any such responsibility shall be divided. Such areas of responsibility may include primary physical residence, education, medical and dental care, and any other responsibilities which the court finds unique to a particular family or in the best interest of the child.

25-5-29. (Effective February 28, 2002) Person other than parent permitted to seek custody of child -- Parent's presumptive right to custody -- Rebuttal. Except for proceedings under chapter 26-7A, 26-8A, 26-8B, or 26-8C, the court may allow any person other than the parent of a child to intervene or petition a court of competent jurisdiction for custody or visitation of any child with whom he or she has served as a primary caretaker, has closely bonded as a parental figure, or has otherwise formed a significant and substantial relationship. It is presumed to be in the best interest of a child to be in the care, custody, and control of the child's parent, and the parent shall be afforded the constitutional protections as determined by the United States Supreme Court and the South Dakota Supreme Court. A parent's presumptive right to custody of his or her child may be rebutted by proof:

25-7-6.14. Abatement of portion of child support -- Shared responsibility cross credit. As used in this section, basic visitation means a parenting plan whereby one parent has physical custody and the other parent has visitation with the child of the parties. In a basic visitation situation, unless the parties otherwise agree and the agreement is approved by the court, the court may, if deemed appropriate under the circumstances, order an abatement of not less than thirty-eight percent nor more than sixty-six percent of the child support if:

The court shall allow the abatement to the obligor in the month in which the visitation is exercised, unless otherwise ordered. The abatement shall be pro-rated to the days of visitation. It shall be presumed that the visitation is exercised. If the visitation exercised substantially deviates from the visitation ordered, either party may file a petition for modification without showing any other change in circumstances.

As used in this section, shared responsibility means a parenting plan whereby each parent provides a suitable home for the child of the parties, the court order allows the child to spend at least one hundred twenty days in a calendar year in each home, and the parents share the duties, responsibilities, and expenses of parenting. In a shared responsibility situation, unless the parties otherwise agree and the agreement is approved by the court, the court may, if deemed appropriate under the circumstances, order a shared responsibility cross credit. The cross credit shall be calculated by multiplying the combined child support obligation using both parents' monthly net incomes by 1.5 to arrive at a shared custody child support obligation. The shared custody child support obligation shall be apportioned to each parent according to his or her net income. A child support obligation is computed for each parent by multiplying that parent's portion of the shared custody child support obligation by the percentage of time the child spends with the other parent. The respective child support obligations are offset, with the parent owing more child support paying the difference between the two amounts. It shall be presumed that the shared responsibility parenting plan is exercised. If the parenting plan exercised substantially deviates from the parenting plan ordered, either party may file a petition for modification without showing any other change in circumstances.