¶ 64. {dissenting). This case presents an oft-recurring situation. A clear answer is needed, one that can readily be applied in the numerous child support cases that present substantially the same issue. The majority opinion does not, in my opinion, fit the bill.
I
¶ 65. The issue presented is "whether... a 33-month unmodifiable floor for child support payments is enforceable." Majority op., ¶ l.1 The majority answers in the affirmative, relying on the equitable power of circuit courts to modify unmodifiable child support orders (notwithstanding the parties' stipulation that it is "unmodifiable"), unforeseen circumstances that adversely affect the best interests of the child, the doctrine of equitable estoppel, case law discussing equitable estoppel, and the duration of an "unmodifiable" stipulation. Majority op., ¶ 3 & passim. Thus, according to the majority opinion, the parties cannot effectively stipulate to unmodifiable child support.
*656¶ 66. Stripping away the language in the majority opinion about the doctrine of equitable estoppel and the application of the doctrine, I read the essence of the majority opinion as holding that a stipulation imposing a floor on child support is enforceable against the payer (here Michael May) unless the payer shows that "unforeseen circumstances" exist at the time the payer seeks to modify child support and that "those circumstances adversely affect the best interests of the child."
¶ 67. I agree with the majority opinion that a circuit court has the power to modify a support order, regardless of whether the stipulation purports to be "unmodifiable." I do not join the majority opinion because there is a simpler, more straight-forward approach to this case.
¶ 68. Once the court acknowledges that the circuit court has the power to modify "unmodifiable" support orders, which it does in the present case, the court should not, in my opinion, create its own rules and standards to govern when this power may be exercised. Rather, Wis. Stat. § 767.59(1©, the statute governing modification of support orders, should take over. Wisconsin Stat. § 767.59(1© demonstrates that the legislature has carefully attempted to shape circuit courts' and parties' power to modify child support. In its entirety, Wis. Stat. § 767.59(1© provides:
SUPPORT: SUBSTANTIAL CHANGE IN CIRCUMSTANCES.
(a) Except as provided in par. (d), a revision under this section of a judgment or order as to the amount of child or family support may be made only upon a finding of a substantial change in circumstances.
(b) In an action under this section to revise a judgment or order with respect to the amount of child support, *657any of the following constitutes a rebuttable presumption of a substantial change in circumstances sufficient to justify a revision of the judgment or order:
1. Commencement of receipt of aid to families with dependent children under s. 49.19 or participation in Wisconsin works under ss. 49.141 to 49.161 by either parent since the entry of the last child support order, including a revision of a child support order under this section.
2. Unless the amount of child support is expressed in the judgment or order as a percentage of parental income, the expiration of 33 months after the date of the entry of the last child support order, including a revision of a child support order under this section.
3. Failure of the payer to furnish a timely disclosure under s. 767.54.
4. A difference between the amount of child support ordered by the court to be paid by the payer and the amount that the payer would have been required to pay based on the percentage standard established by the department under s. 49.22(9) if the court did not use the percentage standard in determining the child support payments and did not provide the information required under s. 46.10(14)(d), 49.345(14)(d), 301.12(14)(d), or 767.511(ln), whichever is appropriate.
(c) In an action under this section to revise a judgment or order with respect to an amount of child support, any of the following may constitute a substantial change of circumstances sufficient to justify revision of the judgment or order:
1. Unless the amount of child support is expressed in the judgment or order as a percentage of parental income, a change in the payer's income, evidenced by information received under s. 49.22(2m) by the department or the county child support agency under s. *65859.53(5) or by other information, from the payer's income determined by the court in its most recent judgment or order for child support, including a revision of a child support order under this section.
2. A change in the needs of the child.
3. A change in the payer's earning capacity.
4. Any other factor that the court determines is relevant.
(d) In an action under this section to revise a judgment or order with respect to child or family support, the court is not required to make a finding of a substantial change in circumstances to change to a fixed sum the manner in which the amount of child or family support is expressed in the judgment or order.
¶ 69. In sum, my preferred holding in the present case is to apply Wis. Stat. § 767.59(lf) to govern the circuit court's power and the rights and responsibilities of payers and payees in modification of a child support order, regardless of whether the stipulation for support (upon which the circuit court's order is based) is purportedly "unmodifiable."
¶ 70. My preferred holding would forthrightly accomplish what the majority opinion might be doing in what I consider a circular, hard-to-follow fashion.
¶ 71. My preferred holding, just like the majority opinion, majority op., ¶¶ 3, 47, deprives parties of the ability to stipulate to a truly unmodifiable child support floor. This result is necessary because freedom of contract cannot take precedence over the best interests of the child.2 While it is more frequently the case that *659raising the amount of child support would be in the child's best interests, situations could arise in which lowering the amount would be in the child's best interests because of fluctuations in the parents' income levels. See majority op., ¶ 35.
¶ 72. When an "unmodifiable" floor or a ceiling on child support is at issue, the judicial methodology, in my opinion, should be the same as when the child support stipulation is silent about whether it is modifiable: Apply Wis. Stat. § 767.59(lf) to determine whether the parties may obtain a modification of child support.
¶ 73. I recognize that "unmodifiable" stipulations are meant to avoid the frivolous, repeated motions that unfortunately sometimes are filed in the aftermath of a contentious divorce. But crucially, courts are not powerless to curb abusive litigation tactics. See majority op., ¶ 7 n.2. More importantly, the legislature has attempted to reduce motions to change child support by creating a high bar for modifying child support (i.e., a substantial change in circumstances) precisely to put a brake on repetitive, unnecessary litigation. If this legislative brake is insufficient, the legislature should create a steeper burden on those seeking modification of child support and impose steeper consequences for frivolous or abusive attempts to modify child support. Until that time, I believe courts should apply Wis. Stat. § 767.59(11).
II
¶ 74. Beyond my fundamental disagreement with the majority's approach, I do not join the majority because its reasoning presents numerous quandaries and glitches.
*660¶ 75. First, the majority's rule is circular. It in effect holds that unmodifiable floors on child support, for limited durations, are enforceable, but explains that they are enforceable because circuit courts may modify them. In other words, a stipulation adopting an unmodifiable floor on child support is enforceable because it is judicially modifiable!
¶ 76. This circularity allows the majority to confusingly and incorrectly apply equitable estoppel in the present case. Majority op., ¶¶ 3, 38-48. The first two elements of estoppel are not implicated by the present case. First, the parties freely and knowingly entered into the stipulation. Second, the terms were fair and equitable to the parties when made.
¶ 77. The confusion arises in the majority's treatment of the third element: Equitable estoppel is not available if the stipulation is contrary to public policy.
¶ 78. The majority holds that the stipulation in the present case is not contrary to public policy because a court may modify it. Majority op., ¶¶ 3, 47. Accordingly, as a matter of law, the payer in the present case is not equitably estopped from seeking a modification.
¶ 79. I understand why the majority opinion falls into the trap of trying to apply equitable estoppel in the present case. Prior cases have analyzed an unmodifiable floor on support in terms of the third element of equitable estoppel (public policy), and the parties' arguments in the present case discuss equitable estoppel and public policy.3 Consequently, the majority opinion feels compelled to use this analysis.
¶ 80. The majority errs, however, because it fails to recognize that the third element of equitable estop*661pel no longer applies because the majority holds, as a matter of law, that the "unmodifiable" floor is judicially modifiable, and consequently the stipulation is not against public policy. Majority op., ¶¶ 3, 47. Thus, as a matter of law, the doctrine of equitable estoppel does not apply in the present case. The majority, is oblivious to the fact that as a result of its opinion, the equitable estoppel analysis falls out of the picture.
¶ 81. Nevertheless, the majority moves to the second question applying the doctrine of equitable estoppel according to our prior case law. The question then becomes, may the payer (here Michael May) get a modification of the support stipulation inasmuch as he is not equitably estopped? In other words, may the circuit court exercise its discretion to modify child support regardless of equitable estoppel? That depends, according to the majority opinion, on whether the payer demonstrates that unforeseen circumstances exist that adversely affect the best interests of the child, which leads me to the next reservation I have about the majority opinion.
¶ 82. Second, the majority opinion unnecessarily introduces new, undefined criteria to cases involving modification of a stipulation on child support.
¶ 83. Are "unforeseen circumstances," majority op., ¶ 3, the same as a "substantial change in circumstances" under Wis. Stat. § 767.59(lf), which governs modification of support orders?4
*662¶ 84. Is "adversely affect the best interests of the child," majority op., ¶ 3, the same standard as "in the best interests of the child?"
¶ 85. I cannot tell whether the majority is creating a higher bar for a circuit court to modify child support when the parties' stipulation is "unmodifiable" than Wis. Stat. § 767.59(lf) provides when the stipulation does not include an "unmodifiable" provision. Since an "unmodifiable" stipulation and a stipulation that does not include an "unmodifiable" provision are, as a matter of law, both judicially modifiable, why shouldn't a court treat the two stipulations the same?
¶ 86. Third, the majority opinion's reliance on a circuit court's power to modify "unmodifiable" stipulations is a break from the analyses in past case law. Because the majority nevertheless relies on equitable estoppel and does not explain prior cases in terms of this change in the analysis, the majority creates confusion and incoherence in the case law.
¶ 87. In prior cases, the court has assumed that an "unmodifiable" stipulation is actually unmodifiable and analyzed the stipulation as such.
¶ 88. For example, in Frisch v. Henrichs, 2007 WI 102, ¶¶ 76-77, 304 Wis. 2d 1, 736 N.W.2d 85, this court held that any unmodifiable stipulation imposing a ceiling on child support violates public policy and is unenforceable. The Frisch court acknowledged that "[t]he ability to contract is fundamental to our legal system and may aid parties in settling their divorces more amicably," but recognized that in the child support context, "the child's best interests are paramount." Frisch, 304 Wis. 2d 1, ¶ 75. A truly unmodifiable ceiling would violate public policy because it would prevent a modification of child support even when there is a *663substantial change in circumstances and modification would be in the child's best interests.
¶ 89. Frisch seems to have been wrongly decided in light of the majority's newfound reliance on the circuit court's equitable power to modify "unmodifiable" stipulations. Under the majority's reasoning, unmodifiable stipulations imposing a ceiling on child support should be enforceable because circuit courts have the discretion to modify them when necessary to protect the child's best interests. Despite the incoherence injected into the Frisch holding by the majority's holding in the present case, the majority opinion, ¶¶ 31, 45-46, claims it reaffirms Frisch (although it adds a new twist that is not present in the Frisch opinion).5
¶ 90. Similar incoherence arises in the majority's treatment of Krieman v. Goldberg, 214 Wis. 2d 163, 571 N.W.2d 425 (Ct. App. 1997). In Krieman, the court of appeals held that an unmodifiable floor on child support that was unlimited in duration violates public policy and is unenforceable. The Krieman court stated that "an unreviewable stipulation for child support could jeopardize a payer parent's financial future . . . ." Id. at 178 (emphasis added). Such a stipulation "may have detrimental effects on the parent/child relationship and in this way would ultimately not serve the best interests of the child." Id.
*664¶ 91. As Krieman demonstrates, under prior case law, the duration of the unmodifiable stipulation was of great importance. But duration was significant because it was understood that "unmodifiable" in the stipulation meant unmodifiable. Duration was a proxy for determining whether the stipulation was in the best interests of the child or against public policy (that is, not in the best interests of the child). The longer the duration of the stipulation, the more likely the stipulation would prevent a modification of child support despite a substantial change in circumstances that rendered the current support not in the best interests of the child.
¶ 92. Under the majority's reasoning, duration should be irrelevant. Yet the majority treats duration as potentially dispositive. Majority op., ¶¶ 36, 44, 47. According to the majority opinion (which admits to being influenced by Wis. Stat. § 767.59(lf)), a 33-month stipulation is acceptable but a stipulation lasting more than four years may be too lengthy. Majority op., ¶ 46. If circuit courts have the power to modify unmodifiable stipulations imposing a floor on child support, why does the duration of the stipulation matter? Under the logic of the majority opinion, an unmodifiable stipulation of unlimited duration imposing a floor on child support is not per se contrary to public policy because the circuit court has the power to modify it at any time for unforeseen circumstances that adversely affect the best interests of the child.
¶ 93. Frisch and Krieman are not the only cases that no longer make sense in light of the majority opinion. A dramatic additional example is Honore v. Honore, 149 Wis. 2d 512, 439 N.W.2d 827 (Ct. App. 1989), in which the court of appeals held that an unmodifiable floor lasting approximately three years was enforceable and not contrary to public policy, *665despite the fact that the stipulation prevented modification of child support even on "a showing of cause." Honore, 149 Wis. 2d at 516.
¶ 94. The present case features a nearly identical fact pattern as Honore. The child support floor is unmodifiable here for 33 months, compared to approximately 36 months in Honore. The majority claims that it is not rejecting "Honore's determination that a three-year stipulation was acceptable," majority op., ¶ 46, but in fact, the majority overrules Honoré sub silentio.
¶ 95. The Honoré court explicitly held that the stipulation could not be modified even on a showing of cause; the floor on child support in Honoré was truly unmodifiable for three years and was nevertheless declared enforceable. Under the majority's reasoning in the present case, Honoré is no longer good law. According to the majority opinion, the Honoré stipulation could be judicially modified for cause within the three-year period, that is, the stipulation would be judicially modified if the payer or payee demonstrated at any time unforeseen circumstances that adversely affected the best interests of the child. The majority does not come to terms with this reality or the incoherence in the case law.
¶ 96. The court of appeals certified the instant case to this court to clarify what the court of appeals saw as confusion in the case law. The certification memorandum asks whether a recent court of appeals decision, Jalovec v. Jalovec, 2007 WI App 206, 305 Wis. 2d 467, 739 N.W.2d 834, which held that a four-year unmodifiable floor on child support was against public policy, was inconsistent with the following footnote in Frisch, 304 Wis. 2d 1, ¶ 74 n.23: "Stipulating to a minimum amount for a limited period of time does not violate public policy because it ensures that a *666certain amount of child support is received, which is in the best interests of the children."
¶ 97. The certification also asked this court to explain whether it mattered for purposes of public policy if the duration of an unmodifiable floor on child support was "tied to" a future time when it would be logical to reexamine support.
¶ 98. How does the majority opinion clarify the meaning and continued validity of the Frisch footnote and the continued validity of Jalovec and other case law developed by the court of appeals? It doesn't.
¶ 99. The majority does not answer the court of appeals' question about a stipulation's duration being "tied to" a logical point in the future. It merely states that stipulations not related to a reasonable future reevaluation point "may not meet with the approval of the circuit court." Majority op., ¶ 47. Under the standard actually adopted by the majority, why does the duration of the stipulation matter, irrespective of whether it is "tied to" a logical point in the future? A court may modify the terms of the stipulation if needed for the best interests of the child.
¶ 100. The majority has created a new approach to unmodifiable stipulations imposing a floor on child support. It focuses on the circuit court's equitable power to modify "unmodifiable" stipulations under certain circumstances and has jammed this approach onto past case law without explaining the dramatic shift in the court's analytical framework. Rather than acknowledging that its methodology clashes with prior case law involving "unmodifiable" floors on child support, the majority tries to save prior cases in some form and muddies the waters even further.
*667III
¶ 101. Despite these concerns, I believe that circuit courts will wisely apply the majority's opinion in the same way that they apply Wis. Stat. § 767.59(lf) to payers and payees seeking to modify child support orders (that do not include any "unmodifiable" provision). The majority's analysis relying on equitable estoppel and unforeseen circumstances that adversely affect the best interests of the child will morph into the statutory standards of "substantial change in circumstances" and "the best interests of the child."
¶ 102. Nevertheless, I dissent rather than concur because the majority errs in its bottom line in the present case.
¶ 103. The majority claims that the circuit court applied the majority opinion's analysis when the circuit court applied equitable estoppel and denied the payer's attempt to modify the stipulation. Majority op., ¶ 48. Yet the circuit court did not know about the majority opinion's newly minted equitable power of the circuit court and therefore could not have applied it and did not apply it.
¶ 104. The circuit court heard legal argument by counsel for both parties about whether the stipulation violated "public policy" (which was not defined) and, relatedly, whether equitable estoppel could apply. Neither counsel nor the circuit court addressed the significance of any "unforeseen circumstances" that might "adversely affect the best interests of the child." Although the circuit court heard counsel briefly summarize background facts that led the payer to seek modification, the circuit court did not hold a hearing to figure out whether there were unforeseen circumstances that adversely affect the best interests of the *668child. The circuit court focused entirely on the question whether a 33-month unmodifiable child support floor was void as a matter of law as contrary to public policy, the third element of equitable estoppel.
¶ 105. The circuit court carefully applied the then-existing equitable estoppel framework. It concluded that the 33-month unmodifiable floor was not void as a matter of law, which satisfied the third legal element of equitable estoppel. Therefore, the payer could be equitably estopped from seeking modification of the "unmodifiable" stipulation.
¶ 106. The circuit court then announced, properly, that it was exercising its discretion whether to apply equitable estoppel in the present case and decided to apply equitable estoppel, but did not explain why it decided to do so, beyond the fact that the legal elements of equitable estoppel were satisfied. The circuit court stated: "So all the requirements for the application of estoppel have been met. I exercise my discretion, which is the final step under [Jalovec], I exercise my discretion to apply the doctrine of estoppel. .. ."
¶ 107. As this court often notes, a discretionary decision must be founded upon proper legal standards.6 In the present case, the circuit court simply concluded that estopping the payer spouse did not violate public policy "where the children's best interest demand that they continue to receive a certain amount of child support or at least a minimum level." This language is reminiscent of Frisch, in which the court explained in a footnote that unmodifiable floors do not violate public policy because they "ensure[] that a certain amount of *669child support is received."7 But the circuit court's discretionary decision was not based on the legal standard the majority creates today. The circuit court made no findings about unforeseen circumstances that might adversely affect the best interests of the child and this court cannot make any such findings on the basis of the record before it.
¶ 108. The majority opinion is correct that the payer has not demonstrated the existence of such circumstances, majority op., ¶ 3, but it fails to acknowledge or realize that the payer was never given the opportunity to make any such demonstration because it was not the focus of the hearing. Thus, under the reasoning of the majority opinion, the matter must be remanded to the circuit court to give the payer an opportunity to demonstrate "unforeseen circumstances" that "adversely affect the best interests of the child."
¶ 109. For the reasons set forth, I dissent.
The circuit court's 2008 judgment incorporated the parties' stipulation regarding child support. Both parties were represented by counsel. Neither party appealed the judgment. Neither party claims in the present proceeding that he or she did not understand the stipulation or that when the stipulation was adopted it was unfair to the parties or was not in the best interests of the child.
See Frisch v. Henrichs, 2007 WI 102, ¶ 75, 304 Wis. 2d 1, 736 N.W.2d 85.
Michael May's brief addresses estoppel but takes a broader view of the case law. See majority op., ¶ 49.
Noting that no statutory definition exists for what constitutes a substantial change in circumstances, the court of appeals has explained that "[o]ne shorthand definition for a substantial change in circumstances is that it is some unforeseen event which occurs after an agreement has been executed." Jalovec v. Jalovec, 2007 WI App 206, ¶ 24, 305 Wis. 2d 467, 739 N.W.2d 834.
The majority opinion at ¶ 34 reads Frisch as holding that ceilings on child support payments are "presumed" to be invalid, citing ¶ 74 of Frisch and Ondrasek v. Tenneson, 158 Wis. 2d 690, 694-96, 462 N.W.2d 915 (Ct. App. 1990). Neither Frisch nor Ondrasek refers to a presumption. Both cases held that the unmodifiable agreements placing a ceiling on child support were per se unenforceable as contrary to the public policy of protecting the best interest of the child.
See, e.g., McCleary v. State, 49 Wis. 2d 263, 277, 182 N.W.2d 512 (1971).
Frisch, 304 Wis. 2d 1, ¶ 74 n.23.