Facts: Parents divorced in 2000 with a parenting plan providing for equal time with the children (alternating weeks) and no child support obligation for either parent.  In 2005, Mother filed a petition to modify the parenting plan based upon conditions in Father’s home and the children’s preference to live with Mother.  While the matter was pending, the parents allowed the children to reside with Mother because that was their preference.  After a hearing, the trial court granted Mother’s petition, modified the parenting plan, and established Father’s child support obligation as of the date of the hearing.  The trial court rejected Mother’s argument that Father’s child support obligation should be made retroactive to the date Mother filed her petition.  Mother appealed.

The Court of Appeals reversed the trial court.

The legal inquiry was whether this was an initial child support order (as Mother argued) or a modification of a prior child support order (as Father argued).  If it was a modification, the trial court would have the discretion to “order the modification effective as of the date of the modification petition, the date of the hearing, or any date in between.” Citing a prior decision, the Court explained:

Both parents have an equal and joint obligation to support their minor children. This obligation exists even if an order awarding child support has not yet been entered. . . . [W]e distinguish this case from cases involving the modification of a parent’s child support obligation, wherein the trial court has the discretion to order the modification effective as of the date of the modification petition, the date of the final hearing, or any appropriate date in between. In modification proceedings, the non-custodial parent is required by a previous court order to make at least some payment toward his or her support obligation during the pendency of the proceedings.

The Court further explained how the trial court lacks discretion when it comes to making an initial child support determination retroactive.

The [Child Support] Guidelines state that if the Court is making an initial setting of child support, the judgment must include support from a particular date, which in this case would be the date the mother took primary physical custody of the children, i.e., the date of the filing of her petition. It is not disputed the mother had actual custody of these children from at least the date of the filing of her petition, and that no support had been paid to her by the father during that time. Under the facts of this case, the Trial Court should have treated this as an initial setting of child support and awarded retroactive support back to the date of the mother’s petition. . . .

[D]uring this time the mother had sole responsibility for their well-being and provided for the children, and their visitation by their choice with the father had been minimal, but he paid no child support during that time. The father has significantly more income than the mother, and . . . both parents had the obligation to support their children, whether there was an order of support or not.

Smith v. Smith (Tennessee Court of Appeals, Sept. 22, 2010).

Information provided by K.O. Herston, Tennessee Divorce Lawyer.