To determine whether special circumstances require that a decision be applied prospectively only, this court applies a three-part test, examining (1) whether the decision establishes a new principle of law, either by overruling clear past precedent or by deciding an issue of first impression, whose resolution was not clearly foreshadowed; (2) whether retroactive operation will further or retard the rule's operation, keeping in mind the purpose and effect of the rule; and (3) how the application matches with concerns about equity, justice, and hardship. Casper v. Casper, 593 N.W.2d 709, 712 (Minn.App. 1999) (citing Hoff, 317 N.W.2d at 363 (citations omitted)). When the second and third factors weigh in favor of retroactivity and the first does not, a decision will be given retroactive application.

The stipulated order, however, retained mother's and father's obligation to split evenly the cost of unreimbursed health expenses, which “are in the nature of child support.” In re Marriage of Casper, 593 N.W.2d 709, 714 (Minn.Ct.App.1999) (quotation omitted). ¶ 71.

. And we review district court decisions regarding medical insurance coverage for an abuse of discretion. Casper v. Casper, 593 N.W.2d 709, 714 (Minn.App. 1999). "A district court abuses its discretion by making findings of fact that are unsupported by the evidence, misapplying the law, or delivering a decision that is against logic and the facts on record."

We also review a district court's decision regarding medical support for an abuse of discretion. Casper v. Casper, 593 N.W.2d 709, 714 (Minn. App. 1999). The district court abuses its discretion if its decision stems from a misapplication of the law or contradicts the facts or logic.

We also review a medical-support determination under an abuse-of-discretion standard. Casper v. Casper, 593 N.W.2d 709, 714 (Minn. App. 1999) (recognizing that a child's medical needs "are in the nature of child support" (quotation omitted)). We will set aside the CSM's findings of fact only if they are clearly erroneous, and we defer to the CSM's opportunity to evaluate witness credibility.

A. FindingsWe review a district court's decision regarding medical support for an abuse of discretion. Casper v. Casper, 593 N.W.2d 709, 714 (Minn. App. 1999). In assessing "whether a parent has appropriate health care coverage" for joint children, a district court must consider the comprehensiveness of the health-care coverage, its accessibility, any special needs of the children, and its affordability. Minn. Stat. § 518A.41, subd. 3.

As a child's medical support is part of child support, this court will not reverse a district court's decision regarding a parent's support obligation absent an abuse of discretion. Casper v. Casper , 593 N.W.2d 709, 714 (Minn.App.1999). Because the parties agreed that their medical insurance policies provided comparable coverage, we must decide whether the district court properly exercised its discretion in finding Todnem's policy to be more affordable.

In addition to overruling Koser, appellant wants this court to adopt the ruling of Holmberg v. Holmberg, 578 N.W.2d 817, 827 (Minn. App. 1998) (concluding that an overpayment remaining after arrearage was paid was windfall to children), aff'd 588 N.W.2d 720 (Minn. 1999), and Casper v. Casper, 593 N.W.2d 709, 713 (Minn. App. 1999) (same). Koser declined to follow Holmberg because

This court reviews a district court's determination of medical support under an abuse-of-discretion standard. See Casper v. Casper, 593 N.W.2d 709, 714 (Minn. App. 1999) ("The medical needs of a minor child, including insurance coverage, 'are in the nature of child support' . . . [and] [t]he district court has discretion in determining child support obligations, and its decision will not be reversed absent an abuse of discretion." (quoting Korf v. Korf, 553 N.W.2d 706, 708 (Minn. App. 1996)).

Further, while the district court's September 2000 posttrial order amended the dissolution judgment to state that appellant's payment of respondent's health-insurance premium "is not spousal maintenance," an obligation to provide health insurance for a former spouse is in the nature of maintenance. See Thompson v. Thompson, 739 N.W.2d 424, 429 (Minn. App. 2007) (stating that "[h]usband did not provide any evidence to rebut wife's need for spousal maintenance in the nature of one-half of wife's medical-insurance premiums"); Casper v. Casper, 593 N.W.2d 709, 714 (Minn. App. 1999) (stating that a child's medical needs, "including insurance coverage, `are in the nature of child support'") (quoting Korf v. Korf, 553 N.W.2d 706, 708 (Minn. App. 1996)). A district court has subject-matter jurisdiction to address maintenance.