concurring in the re-
sult.[¶ 38] Although I am somewhat concerned the trial court merely applied the best interest factors as though this was an original custody order and failed to gauge them against the preference for stability for the children, the court’s rationale for concluding the change of custody was required in the best interests of the children can be deduced from its findings about the lack of stability that existed for a time in the children’s physical environment due to frequent relocations and in their emotional environment due to Susan Kelly’s indiscriminate relationships with men. I, therefore, concur in the result. I write separately because I believe the majority opinion’s citation to Wetch v. Wetch, 539 N.W.2d 309 (N.D.1995) is misplaced in light of the language of N.D.C.C. § 14-09-06.6(6) and the facts of this case. Also, I believe the majority opinion does not correctly set forth the two-step modification of custody analysis of N.D.C.C. § 14-09-06.6(6).
I
[¶ 39] The issue in Wetch was “whether it is error in a change of custody proceeding for a trial court to refuse to consider evidence of relevant custody factors occurring prior to entry of the original custody decree.” 539 N.W.2d at 312. We concluded the trial court abused its discretion in excluding such evidence because the prior custody decisions in Wetch were “based on stipulation of the parties, not upon evidence introduced in a contested proceeding and not by considered fact finding of the court.” Id. at 313. Thus, we remanded the case to the trial court to consider the pre-divorce conduct in its modification of custody analysis. Id.
[¶ 40] Subsequent to our decision in Wetch, the Legislature enacted N.D.C.C. § 14-09-06.6. Section 14-09-06.6(6), N.D.C.C., provides:
The court may modify a prior custody order after the two-year period following the date of entry of an order establishing custody if the court finds:
a. On the basis of facts that have arisen since the prior order or which were unknown to the court at the time of the prior order, a material change has occurred in the circumstances of the child or the parties; and
b. The modification is necessary to serve the best interest of the child.
The majority opinion cites to Wetch in its discussion of N.D.C.C. § 14 — 09—06.6(6)(b), whether the modification is necessary to serve the best interest of the child. See *47Majority Opinion at ¶22. However, the only issue resolved in Wetch, was whether a trial court should “consider” pre-divorce facts in a change of custody proceeding where the prior custody award was based upon a stipulation. See 539 N.W.2d at 312. The determination of what facts a trial court may consider in a change of custody proceeding is now governed by N.D.C.C. § 14-09-06.6(6).
[¶ 41] Under section 14 — 09—06.6(6)(a), N.D.C.C., a court may modify a prior custody order “[o]n the basis of facts that have arisen since the prior order or which were unknown to the court at the time of the prior order.” (Emphasis added). Thus, under 14-09-06.6(6)(a) a trial court should consider facts occurring prior to the entry of an original custody decree based on a stipulation if such facts “were unknown to the court at the time of the prior order.” N.D.C.C. § 14-09-06.6(6)(a). However, establishing what facts a trial court may consider at a modification proceeding merely begins the inquiry under N.D.C.C. § 14^09-06.6(6). More difficult is the use of this evidence in the application of the statutorily required findings. As explained by an Illinois Appellate Court in construing a statute somewhat similar to N.D.C.C. § 14-09-06.6(6):
Section 610 allows the court in making its decision to rely upon facts that have arisen since the prior judgment or that were unknown to the court at the time of entry of its prior judgment. Our court had an opportunity to address this section in Boggs v. Boggs (1978), 65 Ill.App.3d 965 [22 Ill.Dec. 645] 383 N.E.2d 9. There we stated:
“Section 610(b) clearly states that evidence may be received of either newly arisen facts or those unknown to the court at a prior hearing. Obviously, the reference to facts which were unknown at prior hearing includes a reference to such facts which were then in existence. Otherwise there would be no reason to refer to such facts because they would fall into the category of newly arisen facts. Not so clear is an answer to the question of whether the unknown facts in existence at the time of the prior hearing may be considered as bearing on the change of circumstances requirement. Obviously, facts in existence at a prior time cannot be the basis of a change in circumstances taking place after that time. However, the wording of 610(b) is constructed in such a way as to indicate that evidence of both newly arisen facts and those previously unknown to the court can be considered not only on the question of the child’s best interests but also on the change of circumstances requirement.
... [We] construe the words ‘a change has occurred in the circumstances of the child or his custodian’ to mean that a change in circumstances as previously shown to the court has occurred. That construction would enable the court hearing the petition to modify to exercise its judicial discretion rather than be bound by the previous order based upon an agreement. We adopt that construction.” 65 Ill.App.3d 965, 967-68 [22 Ill.Dec. 645] 383 N.E.2d 9, 11-12.
We do not suggest that every time a noncustodial parent seeks to modify a stipulated custody judgment the court is to automatically find a change of circumstances and proceed to a decision based on the best interest of the child. The court must still weigh the evidence and find if the circumstances existing at the time of the prior custody hearing were different than they appeared. If the evidence indicates the custodial parent was fit and acceptable at the time of the prior hearing, then modification *48must rest on subsequent change of circumstances of the child or of the child’s custodian. However, if the evidence indicates a lack of fitness at the time of the prior agreed judgment, then that factor should be considered in determining the propriety of a modification under the provisions of section 610 which require clear and convincing evidence.
In re Marriage of Gibbons, 158 Ill.App.3d 998, 111 Ill.Dec. 148, 512 N.E.2d 52, 55 (1987) (emphasis added).2
[¶ 42] Similarly, under N.D.C.C. § 14-09-06.6(6)(a), a court must find that a material change in circumstances has occurred based on facts that have arisen since the prior order or that were unknown to the court. See N.D.C.C. § 14-09 — 06.6(6)(a). However, under the wording of N.D.C.C. § 14-09-06.6(6), the language “[o]n the basis of facts that have arisen since the prior order” only modifies the finding of a material change in circumstances and not subsection (b) relating to the best interest analysis. The question becomes whether the Legislature intended to permit the trial court to “rehash” facts existing both prior to and at the time of the prior custody order or to limit the evidence considered in the best interest analysis also to those that have arisen since the last custody order or that were unknown to the court. The doctrine of res judicata would make it inappropriate to rehash facts already tried or which could have been tried. Even Wetch was limited to cases involving stipulations. 539 N.W.2d at 313.
[¶ 43] However, we need not decide that issue in this case because Susan has never raised any issue regarding the consideration of pre-divorce evidence at the trial court level or on appeal. Thus, the majority’s citation to Wetch at ¶¶ 22 and 33 is misplaced. What Susan does argue is that the trial court erred in its application of N.D.C.C. § 14-09-06.6(6) by failing to properly weigh her past moves, health problems, and transitional relationships against the recent stability and continuity she had been providing her children.
II
[¶ 44] Section 14-09-06.6(6), N.D.C.C., was generally intended to codify this Court’s two-step approach to modification of custody determinations. See Anderson v. Resler, 2000 ND 183, ¶8, 618 N.W.2d 480 (“In 1997, the legislature codified this Court’s two-step approach for deciding a change of custody request.”). Under the two-step approach relied on by this court prior to the enactment of N.D.C.C. § 14-09-06.6(6), we recognized “[u]nlike an initial custody determination in which the trial court considers only the best interests and welfare of the child, a motion to modify custody requires a two-step analysis.” *49Anderson v. Hensrud, 548 N.W.2d 410, 412 (N.D.1996). “First, the trial court must determine whether there has been a significant change in circumstances since the original custodial placement.” Id. “If there has been a significant change in circumstances, then the trial court must determine whether the significant change compels, in the child’s best interests, a change in custody.” Id. “The two-step analysis reflects the ‘doctrinal aversion to changing the custody of a happy child who has been living with one parent for a substantial time.’ ” Id. (quoting Alvarez v. Carlson, 524 N.W.2d 584, 590 (N.D.1994)). We have noted, “the important factor in any change of custody proceeding is the stability of the child’s relationship with the custodial parent,” and “[i]t is the continuity of the custodial parent-child relationship that is critical.” Ramstad v. Biewer, 1999 ND 23, ¶¶ 14, 15, 589 N.W.2d 905.
[¶ 45] The clear legislative intent of N.D.C.C. § 14-09-06.6 is to make custody determinations as permanent as possible and to curtail repeat “painful, disruptive, and destabilizing” custody battles. See Quarne v. Quarne, 1999 ND 188, ¶¶ 9-10, 601 N.W.2d 256. The question is how does N.D.C.C. § 14-09-06.6(6) accomplish the Legislature’s purpose of curtailing custody battles and of providing stability in the lives of children without the requirement that the material change in circumstances must compel or require a change in custody to further the best interests of the child.
[¶ 46] Under the first step of the two-step approach of our prior case law, a party moving for a modification of custody had to show that a significant change in circumstances occurred since the prior custody order. Under our prior case law, we defined a “change in circumstances” as “new facts that were unknown at the time of the prior custodial decree.” See Mc-Donough v. Murphy, 539 N.W.2d 313, 316 (N.D.1995); Alvarez, 524 N.W.2d at 589. Unfortunately, some of our recent cases have relied on this same definition to determine whether a “material” change has occurred in the circumstances of the child or the parties under N.D.C.C. § 14-09-06.6(6)(a). See Selzler v. Selzler, 2001 ND 138, ¶ 21, 631 N.W.2d 564 (“A material change in circumstances occurs when new facts are presented that were unknown to the moving party at the time the divorce decree was entered.”); Mayo v. Mayo, 2000 ND 204, ¶ 16, 619 N.W.2d 631 (same). However, we have also said that a “significant change in circumstances” is one that “so adversely affect[s] the child that custody should be changed,” Blotske v. Leidholm, 487 N.W.2d 607, 609 (N.D.1992), and “so adversely affects the child that a change of custody is necessary,” Alvarez, 524 N.W.2d at 589. Under N.D.C.C. § 14 — 09—06.6(6) (a), a trial court must make a finding that a “material change has occurred in the circumstances of the child or the parties” on facts “that have arisen since the prior order or which were unknown to the court at the time of the prior order.” This clearly means that it is after the court identifies new facts or changes in circumstances that it then determines whether these changes are a “material” change in circumstances. See Overboe v. Farm Credit Serv. of Fargo, 2001 ND 58, ¶ 10, 623 N.W.2d 372 (“If possible, each word of a statute must be given effect.”). Thus, in enacting N.D.C.C. § 14-09-06.6(6)(a), the Legislature clearly intended the occurrence of a material change in the circumstances of the child or the parties to be something more than the mere presentation of new facts that were unknown, to the moving party at the time the divorce decree was entered. See Mayo, at ¶ 16.
[¶ 47] The Legislature did not define a “material” change in circumstances, and it is very important, therefore, for our Court *50to interpret what is meant. In accord with the purpose of the legislation, the finality of decrees and the preference for stability of the custodial parent-child relationship, the determination of whether there is a material change of circumstances must be met only by evidence of a significant or important change that has a negative impact on the well-being of the child. This would adequately provide a threshold that would guard against modification of a prior custody decree and preserve the public policy in favor of stability for the children. The purpose of requiring moving parties to make this showing is similar to the purpose that was served by the requirement of our two-step approach which required the significant change in circumstances to compel a change in custody in order to serve the best interest of the child. See Ramstad, 1999 ND 23, ¶ 27, 589 N.W.2d 905 (Vande Walle, C.J., concurring in result) (“The requirement that the changes in circumstances necessary to support a change in custody must compel or require that change, expresses our position that because of the significance of stability in a child’s life, the custody of that child is not to be changed as a result of every change in circumstances of the parents.”).
[¶ 48] This interpretation of section 14-09-06.6(6) is supported by an examination of N.D.C.C. § 14-09-06.6(4). See North Dakota Fair Housing Council, Inc., v. Peterson, 2001 ND 81, ¶ 36, 625 N.W.2d 551 (“ ‘Statutes relating to the same subject matter shall be construed together and should be harmonized, if possible, to give meaningful effect to each, without rendering one or the other useless.’ ”). Section 14-09-06.6(6) was adopted at the same time as N.D.C.C. § 14-09-06.6(4). Under 14-09-06.6(4), N.D.C.C., a party seeking modification of custody must first submit briefs and affidavits which establish a “pri-ma facie case justifying a modification” before the party is entitled to an evidentia-ry hearing. In enacting N.D.C.C. § 14-09-06.6(4), the Legislature recognized that an evidentiary hearing to determine a child’s best interest was often a difficult and time-consuming process for the child and the parents. See Hearing on SB 2167 before the Senate Judiciary Committee, 55th N.D. Leg. Sess. (Jan. 21, 1997) (testimony of Sherry Mills Moore). Thus, the purpose of N.D.C.C. § 14-09-06.6(4) was to curtail the number of these hearings by bifurcating the test for modification of custody. See id. Therefore, under N.D.C.C. § 14-09-06.6(4), a trial court is to first determine, from the briefs and affidavits, if the moving party has established a “prima facie case justifying a modification.” Only if a “prima facie case justifying a modification” is established, will a party be entitled to an evidentiary hearing to determine if modification is necessary to serve the best interest of the child. See N.D.C.C. § 14-09-06.6(4). In bifurcating these two steps, the Legislature hoped to not only prevent needless changes in custody, but to also spare children from the harmful effects of the custody battle itself. See Hearing on SB 2167 before the Senate Judiciary Committee, 55th N.D. Leg. Sess. (Jan. 21, 1997) (testimony of Sherry Mills Moore).
[¶ 49] The standards that a party must meet to establish a “prima facie case justifying a modification” are provided in subsections 5 and 6 of N.D.C.C. § 14-09-06.6. In the two-year period following the entry of an order establishing custody, a “prima facie case justifying a modification” is established if the moving party shows, through the submission of briefs and affidavits, willful interference with visitation, danger to the child’s health, or a change in primary physical care of the child to the other parent for longer than six months. See N.D.C.C. § 14r-09-06.6(4)-(5). If the moving party succeeds in showing one of these things, it is then entitled to an evi-*51dentiary hearing to determine if “modification is necessary to serve the best interest of the child.” See N.D.C.C. § 14-09-06.6(5). After the two-year period following the entry of a custody order, a “prima facie case justifying a modification” is established if the moving party shows, through the submission of briefs and affidavits, -that, on the basis of facts which have arisen since the prior custody order or which were unknown to the court at the time of the prior order, a material change in circumstances of the child or the parties has occurred. See N.D.C.C. § 14-09-06.6(4), (6)(a). Only if the moving party succeeds in this showing will it be entitled to an evidentiary hearing to determine if “modification is necessary to serve the best interest of the child.” See N.D.C.C. § 14-09-06.6(6)(b).
[¶ 50] When viewed in the context of its relationship to N.D.C.C. § 14-09-06.6(4), it is clear that the material change of circumstances requirement of N.D.C.C. § 14-09-06.6(6)(a) must require something more of parties than the mere presentation of new facts “that were unknown to the moving party at the time the divorce decree was entered,” see Selzler, 2001 ND 138, ¶ 21, 631 N.W.2d 564. As discussed above, N.D.C.C. § 14-09-06.6(6)(a) provides the standard for determining if a party has established a “prima facie case justifying a modification” under N.D.C.C. § 14-09-06.6(4). The Legislature intended this standard to curtail the number of evidentiary hearings on the best interest factors. This standard would be of little, if any, help in reducing the number of best interest hearings if it could simply be met by a showing of new facts “that were unknown to the moving party at the time the divorce decree was entered.” Selzler, 2001 ND 138, ¶ 21, 631 N.W.2d 564. Rather, it is clear the Legislature intended to require parties to meet the higher standard of showing that there has been a significant or important change of circumstances that has a negative impact on the well-being of the child.
[¶ 51] The second step, after the trial court has found a material change in circumstances, is to apply the best interest factors in N.D.C.C. § 14-09-06.2 gauged against the preference for stability of the custodial parent-child relationship. In Blotske, we described how a trial court is to apply the best interest factors:
We have said that in determining the best interests of a child in a change of custody proceeding, the trial court is to apply the factors in N.D.C.C. § 14-09-06.2. However, that application must be done within the constraints of a modification proceeding, as contrasted to an original custody proceeding. In an original custody proceeding, the fact finder is given free rein to weigh each factor as it deems fit, under no constraints (in the majority view) to assign one factor priority or give one factor more weight than another. A trial court making an original award of custody must determine the single issue of what is in the child’s best interests. But a modification proceeding is different from an original custody award. In a modification proceeding, the best interests of the child must be gauged against the backdrop of the stability of the child’s relationship with the custodial parent.
Blotske, 487 N.W.2d at 610 (citations omitted). It is this analysis that a trial court must apply in N.D.C.C. § 14-09-06.6(6)(b), “[t]he modification is necessary to serve the best interest of the child.” Evidence that establishes the first step, a material change of circumstances, can also be considered by the trial court under N.D.C.C. § 14-09-06.2, the best interest factors, in the second step of the analysis. However, such evidence may be more significant in the court’s consideration of one step of the *52analysis than the other step. See McDonough, 539 N.W.2d at 317; Alvarez, 524 N.W.2d at 589.
[¶ 52] In summary, in my opinion, the proper method for analyzing a motion to change custody is, first, the moving party must submit affidavits and briefs in support of the motion. N.D.C.C. § 14-09-06.6(4). Based on these briefs and affidavits, the trial court must determine if the party has established a “prima facie case justifying a modification.” Id. If the motion is brought in the two-year period following the entry of a custody order, a “prima facie case justifying a modification” is established by showing any of the three items listed under N.D.C.C. § 14-09-06.6(5). If the motion is brought after this two-year period, a “prima facie case justifying a modification” is established if the court finds a material change has occurred in the circumstances of the child or the parties. See N.D.C.C. § 14-09-06.6(4), (6)(a). A material change in circumstances is a significant or important change that has a negative impact on the well-being of the child. See Alvarez, 524 N.W.2d at 589; Blotske, 487 N.W.2d at 609. Only when a party meets the standards for a “prima facie case justifying a modification” is the court required to hold an evidentiary hearing to determine if “modification is necessary to serve the best interest of the child.” See N.D.C.C. § 14-09-06.6(4), (6)(b). At that point, the best interest factors must be gauged against the preference for the stability of the custodial parent-child relationship. Such a construction of N.D.C.C. § 14-09-06.6 gives meaning to every word of the statute and furthers the Legislature’s intent of curtailing changes in custody and providing stability to children.
Ill
[¶ 53] I, therefore, respectfully concur in the result only.
[¶ 54] MARY MUEHLEN MARING and WILLIAM A. NEUMANN, JJ„ concur.. The statute at issue in Gibbons provided:
After the expiration of the 2 year period following a custody judgment specified in subsection (a) of this Section, the court shall not modify a prior custody judgment unless it finds by clear and convincing evidence, upon the basis of facts that have arisen since the prior judgment or that were unknown to the court at the time of entry of the prior judgment, that a change has occurred in the circumstances of the child or his custodian, or in the case of a joint custody arrangement that a change has occurred in the circumstances of the child or either or both parties having custody, and that the modification is necessary to serve the best interest of the child. In the case of joint custody, if the parties agree to a termination of a joint custody arrangement, the court shall so terminate the joint custody and make any modification which is in the child's best interest.
1982 Ill. Laws 82-1002 Sec. 610(b). Since the decision in Gibbons, Illinois's modification statute has been amended in ways not pertinent to this case. See 750 Ill. Comp. Stat. Ann. 5/610(b) (West 1999).