Mary Johnson (Plaintiff) appeals orders dated 6 October 2000 and 18 October 2000 modifying Plaintiff’s sole custody of the minor child Mary Catherine Adolf (Katie) to joint legal custody with the biological parents, Louis Adolf (the Father) and Mary Adolf (the Mother) (collectively, Defendants).
Katie was born 10 April 1992 and is the maternal granddaughter of Plaintiff. In March 1996, a court order was entered granting joint *877custody of Katie to Plaintiff and Defendants. During the fall of 1996, the Mother, who had care of Katie during the day, was hospitalized twice with delusional and irrational thought patterns for which her doctor increased her medications. Around this time, Katie and her brother were found several times playing in the streets and a report was filed with the Carrollton County Department of Social Services in Kentucky. On several occasions in 1997, Katie arrived at her half-day preschool program without a lunch and improperly clothed. After these occurrences, Plaintiff moved the trial court on 7 February 1997 to modify the March 1996 custody order. In August 1997, the trial court awarded sole custody of Katie to Plaintiff, finding the Defendants unfit to have custody because of the Mother’s periods of delusional behavior, Defendants’ nomadic lifestyle in that they had moved six times since Katie’s birth, and the Father’s failure to demonstrate the necessary insights into his wife’s condition that would allow Katie to be safe in the home.
On 19 May 1999, Defendants filed a motion to modify the August 1997 custody order. In an order filed 18 October 2000 nunc pro tunc for 9 June 2000, the trial court found as fact that “there had been a substantial change in circumstances since 1997.”
The trial court concluded as a matter of law that:
2. The proper standard for deciding whether a modification of custody is justified is whether there has been a substantial change in circumstances affecting the welfare of the child. If there has been a substantial change in circumstances, then the [trial] court must consider whether a change in custody would be in the best interest of the child. Bivens v. Cottle [,] 120 N.C. App. 467, 462 S.E.2d 829 (1995).
3. There have been changes in circumstances since August 1997.
4. It is not, however, in [Katie’s] best interest to move her custody from North Carolina to Iowa at this time.
The trial court further stated it was not entering a permanent order, but it would give Defendants thirty days to consider whether they would be willing or able to move to Durham, North Carolina.
At a 24 July 2000 hearing, the Father informed the trial court that he had a job offer from a firm in Greenville, North Carolina, and had made steps toward moving back to North Carolina. In an order dated *8786 October 2000, issuing from the 24 July 2000 hearing, the trial court decreed that Plaintiff and Defendants would share joint legal custody of Katie, with physical custody remaining with Plaintiff until further order from the trial court.
The dispositive issue is whether conclusions exist showing that there has been a substantial change of circumstances affecting the welfare of the child and that it is in the best interest of the child to place joint legal custody with Plaintiff and Defendants.
In a custody modification action, even one involving a parent, the existing child custody order cannot be modified except upon a showing by the party seeking a modification that there has been a substantial change in circumstances affecting the welfare of the child and if so, that a change in custody is in the best interest of the child. Bivens v. Cottle, 120 N.C. App. 467, 469, 462 S.E.2d 829, 831 (1996), appeal dismissed, 346 N.C. 270, 485 S.E.2d 296 (1997). The trial court must first determine whether the movant has met her burden of making these showings. Id. Because these determinations involve an exercise of judgment and an application of legal principles, they are appropriately classified as conclusions of law. See In re Everette, 133 N.C. App. 84, 85, 514 S.E.2d 523, 525 (1999).
In this case, the trial court stated there “had been a substantial change in circumstances” since entry of the August 1997 custody order.1 The trial court never determined, however, that the changes impacted the child, either positively or negatively. See Pulliam v. Smith, 348 N.C. 616, 620, 501 S.E.2d 898, 900 (1998). Furthermore, assuming the changes impacted the child, the trial court never assessed (in its orders) whether it is in the best interest of the child that the August 1997 child custody order be modified. For these reasons, the orders of the trial court must be reversed and remanded. On remand, because it has been some eighteen months since the entry of the orders modifying custody, the trial court must take new evidence and enter a new order in response to Defendants’ 19 May 1999 motion for change of custody.
Judges McGEE and CAMPBELL concur.