In Re the Marriage of: Bryan S. Skupas, petitioner, Appellant, vs. Dianna M. Skupas, n/k/a Dianna M. Bourgeios, Respondent.

may not be cited except as provided by

Minn. Stat. § 480 A. 08, subd. 3 (1996).

 STATE OF MINNESOTA

 IN COURT OF APPEALS

C5-97-2190

In Re the Marriage of:

Bryan S. Skupas, petitioner,

Appellant,

vs.

Dianna M. Skupas, n/k/a

Dianna M. Bourgeios,

Respondent.

 Filed June 9, 1998

Affirmed

 Peterson, Judge

Dakota County District Court

File No. F79513258

Stuart L. Finney, Fuller & Finney, 7301 Ohms Lane, Suite 325, Edina, MN 55439 (for appellant)

Dianna M. Bourgeois, 4051 152nd Court West, Rosemount, MN 55068 (respondent pro se)

Considered and decided by Peterson, Presiding Judge, Crippen, Judge, and Mansur, Judge.[*]

U N P U B L I S H E D O P I N I O N

 PETERSON, Judge

Appellant-father claims the district court erred in apportioning the costs of a visitation expediter. We affirm.

 FACTS

The stipulated 1995 judgment dissolving the marriage of appellant-father Bryan S. Skupas and respondent-mother Dianna M. Skupas, n/k/a Dianna M. Bourgeois: (a) awarded mother custody of the parties' child; (b) awarded father unspecified visitation; (c) required visitation disputes to be resolved by mediation; and (d) required the parties to equally share mediation costs. Since entry of the judgment, the parties have had a series of acrimonious visitation disputes. In September 1997, the district court appointed a visitation expediter and ordered the parties to share the expediter's costs in proportion to their incomes. Father appeals.

 D E C I S I O N

The district court "shall modify an order granting or denying visitation rights whenever modification would serve the best interests of the child." Minn. Stat. § 518.175, subd. 5 (Supp. 1997). Because the order granting visitation rights is subject to modification, and because the portion of the judgment granting visitation rights requires the parties to equally share the costs of mediating visitation disputes, whether to modify the apportionment of the costs of the visitation expediter is discretionary with the district court. See Gray v. Hauschildt, 528 N.W.2d 271, 273 (Minn. App. 1995) (determination and enforcement of visitation rights are legal questions but other visitation-related questions are discretionary with the district court).

Father cites Beck v. Kaplan, 566 N.W.2d 723, 726 (Minn. 1997) and Claybaugh v. Claybaugh, 312 N.W.2d 447, 449 (Minn. 1981) to argue the district court's ability to modify stipulated agreements is limited. Beck and Claybaugh involve stipulated maintenance awards; awards where the stipulating parties are the ones whose rights will be impacted by the stipulation. Beck 566 N.W.2d at 725; Claybaugh, 312 N.W.2d at 449. The supreme court has not extended the same deference to stipulations that directly impact the rights of children. See Moylan v. Moylan, 384 N.W.2d 859, 865 (Minn. 1986) (admitting a stipulation is an "important element" in considering a party's motion to modify stipulated support obligation, but holding stipulations addressing support are "afforded less weight" because they address "the non-bargainable interests of the children"). Giving the parties' apportionment of mediation costs less deference than a maintenance stipulation is consistent with the direct impact visitation has on the interests of a child and the statutory standard for modifying visitation orders being the child's best interests. Minn. Stat. § 518.175, subd. 5. Therefore, we review whether the district court abused its discretion by modifying the judgment to apportion the costs of the visitation expediter in proportion to the parties' incomes. We conclude it did not. See Minn. Stat. § 518.1751, subd. 2a (Supp. 1997) (district court may apportion the costs of a visitation expediter and may reapportion those costs if initial apportionment is not equitable). Cf. Minn. Stat. § 518.171, subd. 1(d) (Supp. 1997) (unless agreed otherwise by parties and approved by court, when medical support recipient does not receive public assistance, court "shall" apportion medical support costs based on parties' net incomes).

Father argues the stipulation is "law of the case" under Karon v. Karon, 435 N.W.2d 501, 503 (Minn. 1989). Karon does not address law of the case. Further, because there has been no prior appellate ruling or remand regarding the discretionary apportionment of visitation costs, there is no reason to apply the doctrime of law of the case here. See Loo v. Loo, 520 N.W.2d 740, 744, n.1 (Minn. 1994) (law of the case "ordinarily" applies where appellate court rules on a "legal issue" and remands to district court).

Father cites Borgeson v. Borgeson, 461 N.W.2d 402, 403 (Minn. App. 1990) to argue the district court lacks jurisdiction to address the costs of the expediter. Borgeson, addresses a district court's ability to modify maintenance when the judgment includes a divestiture of jurisdiction over maintenance. 461 N.W.2d at 402-03. Here, there was a divestiture of jurisdiction over maintenance. There was, however, no divestiture of jurisdiction over mediation costs. If father is arguing the divestiture of jurisdiction over maintenance should apply to mediation costs, he cites no supporting authority. See Schoepke v. Alexander Smith & Sons Carpet Co., 290 Minn. 518, 519-20, 187 N.W.2d 133, 135 (1971) (assignment of error based on "mere assertion" and not supported by argument or authority is waived unless error is obvious). Further, any such claim is inconsistent with case law. See Loo, 520 N.W.2d at 745 (absent "a clear or express statement divesting the court of jurisdiction[,]" courts should not assume divestiture was intended).

Father claims that, under Kellen v. Kellen, 367 N.W.2d 648, 650-51 (Minn. App. 1985), apportionment of visitation-related expenses is functionally a modification of child support and requires the substantial change in circumstances required by Minn. Stat. § 518.64, subd. 2 for a support modification. We previously rejected this argument. See Ballard v. Wold, 486 N.W.2d 161, 163 (Minn. App. 1992) (noting "Kellen's holding was unique to its circumstances"). Also, while this case bears some similarity to Kellen, we conclude it is more like Ballard because the costs of the visitation expediter are new and, at least at this point, it appears they will be permanent. For this reason, and given Kellen's uniqueness, the district court did not err by not applying Kellen here.

  Affirmed.

[*] Retired judge of the district court, serving by appointment pursuant to Minn. Const. art. VI, § 10.