Florida Bar Journal

Retroactivity (or Not) of the Equal Timesharing Presumption

In 2023, the Florida Legislature adopted several amendments to F.S. §61.13. One of those amendments added “a rebuttable presumption that equal timesharing of a minor child is in the best interests of the minor child,” and provided that this presumption could be rebutted by a preponderance of the evidence.^[1] It is not immediately clear, however, whether a court considering a petition to modify an existing parenting plan that was established before the amendment’s effective date must apply this presumption.

This is not an easy question. Although this article ultimately concludes that the amendment is not retroactive to existing parenting plans, reaching a reliable conclusion on this issue requires thoughtful, fair-minded analysis.

To unpack this question in a meaningful way, I briefly discuss the changes that the 2023 Florida Legislature made to the relevant statute and provide an overview of the doctrine regarding retroactivity. I then assess whether the equal timesharing presumption should apply retroactively to existing parenting plans that were established before its effective date.

A Brief Overview of Parenting Plans, Time-sharing Plans, and Related Procedures

Before launching into a technical discussion of the 2023 amendments and their possible retroactivity, it is helpful to set the scene by defining the relevant terms and explaining how they all fit together.

“Parenting plan” and “time-sharing schedule” are closely related and have statutory definitions.^[2] The definition for “parenting plan” is especially lengthy, clocking in at 288 words spread over multiple subsections.^[3] Essentially, though, a parenting plan is a court order that governs the parents’ relationship vis-à-vis a minor child.^[4] Parents may agree to a parenting plan for the court to approve, or the court may establish one.^[5] Additionally, a parenting plan must contain a “time-sharing schedule.”^[6]

A “time-sharing schedule” is more specifically defined as “a timetable that must be included in the parenting plan that specifies the time, including overnights and holidays, that a minor child will spend with each parent.”^[7] As one might expect, parenting plans and time-sharing schedules often feature in dissolution of marriage cases and paternity cases.

Not all parenting plans are created equal. However, the law distinguishes between what I call “first-instance plans,” which are established when no prior parenting plan existed, and parenting plans that are modifications of a pre-existing parenting plan, which I refer to as “modification plans.” The touchstone in both types of parenting plan is the best interests of the child.^[8] The exception, however, is that “modification of a parenting plan and time-sharing schedule requires a showing of a substantial and material change of circumstances.”^[9]

This substantial change requirement “promotes the finality of the underlying time-sharing order…[,] establishes a presumption in favor of the reasonableness of the original decree and recognizes the [res judicata] effect of the final judgment.”^[10] Because the party seeking modification must first carry this “extraordinary burden” before the trial court can consider whether a modification is in the child’s best interests, “the trial court does not have the same broad discretion to modify [a parenting plan] that it exercises in initial determinations establishing a first-instance parenting plan.”^[11] With that groundwork in place, we can proceed to consider the statute.

What the 2023 Amendment Did

The Florida Legislature has bled many a red pen dry over the years on §61.13. As of January 2025, the section has been amended 67 times since its adoption in 1828.^[12] The frequency of these amendments has had crests and troughs, but the current millennium has seen 30 amendments in just 24 years, for an average of 1.25 amendments per year.^[13] This remarkable rate of legislative tinkering shows both that family law is an exciting and dynamic field, and also that the workings of this statute are a matter of intense and consistent concern to Florida’s policymakers. It is fair to say that Florida’s law on timesharing and parenting plans has not led an unexamined life.

Section 61.13 covers much territory and has many moving parts, but what concerns us here is §61.13(2), which regulates parenting plans for minor children. The version of the statute in force before the 2023 amendments — at least, the part of it at interest here — provided:

It is the public policy of this state that each minor child has frequent and continuing contact with both parents after the parents separate or the marriage of the parties is dissolved and to encourage the parents to share the rights and responsibilities, and joys, of childrearing. Except as otherwise provided in this paragraph, there is no presumption for or against the father or mother of the child or for or against any specific time-sharing schedule when creating or modifying the parenting plan of the child.^[14]

F.S. Ch. 2023-301, §1, amended subparagraph (2)(c)1 to read:

It is the public policy of this state that each minor child has frequent and continuing contact with both parents after the parents separate or the marriage of the parties is dissolved and to encourage the parents to share the rights and responsibilities, and joys, of childrearing. Unless otherwise provided in this section or agreed to by the parties, there is a rebuttable presumption that equal time-sharing of a minor child is in the best interests of the minor child. To rebut this presumption, a party must prove by a preponderance of the evidence that equal timesharing is not in the best interests of the minor child. Except when a time-sharing schedule is agreed to by the parties and approved by the court, the court must evaluate all of the factors set forth in subsection (3) and make specific written findings of fact when creating or modifying a timesharing schedule.^[15]

This article focuses on the emphasized part, which both establishes a new rebuttable presumption in favor of equal timesharing, and sets forth the conditions under which that presumption can be rebutted.

On a first reading, one might be excused for wondering what the big deal is about this amendment. After all, once a party seeking modification established that there was a substantial and material change in circumstances under the pre-2023 version of §61.13(2)(c)1, that party was always going to have to prove their requested modification was in the child’s best interests. The preponderance of the evidence standard was the relevant threshold for that determination. In this cursory reading, the 2023 amendment merely makes explicit what the law always, in practical terms, required.

But on closer inspection, the question before the trial court changes substantially. Rather than asking what modifications to the existing parenting plan are in the child’s best interests, the 2023 amendment wipes the slate clean and requires the trial court to assume that 50/50 timesharing is in the child’s best interests unless one of the parties proves otherwise by a preponderance of the evidence, regardless of what the existing parent plan established.^[16] The question is not what modifications are in the child’s best interests, but rather whether anything other than equal timesharing is in the child’s best interests. Before the 2023 amendment, the trial court’s starting point was the pre-existing parenting plan. After the 2023 amendment, it starts from scratch.

Florida’s Retroactivity Doctrine in Brief

Given that the 2023 amendment to §61.13(2)(c)1 makes a difference to how courts treat petitions for modification of existing parenting plans, the natural next question is when to apply those changes. Florida’s courts have developed a substantial and nuanced judicial doctrine of statutory retroactivity, but a simplified survey will suffice for present purposes.^[17]

Florida’s retroactivity doctrine begins by dividing statutes into two categories: procedural and substantive. “The general rule is that a substantive statute will not operate retrospectively absent clear legislative intent to the contrary, but that a procedural or remedial statute is to operate retrospectively.”^[18] To describe this rule as “well established” is an understatement: The earliest Florida case referring to it dates from 1885.^[19]

So, if an amendment is procedural, it is treated as remedial and applied retroactively. If an amendment is substantive, one must ask additional questions. In their simplest form, those questions are: “First if the relevant provision provides for retroactive application, and second if such application is constitutionally permissible.”^[20] Put differently, one must ask of a substantive statute: 1) whether the legislature provided for the statute to apply retroactively; and 2) whether a higher legal authority — the U.S. and Florida constitutions — permits that instruction to be carried out.

To answer the first question, one examines whether the legislature provided for retroactive application by reading the law itself. To be retroactive, a substantive statute must affirmatively and clearly state that it shall be retroactive.^[21] If the legislature adopts an effective date for the legislation, that is a strong signal that it shall only apply prospectively.^[22] This makes sense. If the legislature says an act must become effective on such-and-such a date, then the courts’ duty is to give it effect on and after that date, but not before.

The second question is often more nuanced. “Even when the [l]egislature does expressly state that a statute is to have retroactive application, [courts have] refused to apply a statute retroactively if the statute impairs vested rights, creates new obligations, or imposes new penalties.”^[23] This is a constitutional question, because “retroactive abolition of substantive vested rights is prohibited by constitutional due process considerations.”^[24] Retroactive application is forbidden “in those cases wherein vested rights are adversely affected or destroyed or when a new obligation or duty is created or imposed, or an additional disability is established, on connection with transactions or considerations previously had or expiated.”^[25]

Applying the Retroactivity Analysis to the Equal-Timesharing Amendment

With that foundation laid, we can discuss whether the 2023 equal timesharing amendment applies to various types of parenting plans. There are a number of possible permutations here. I focus on two. First, the simplest situation is a first-instance plan that is created following a petition filed on or after the 2023 amendment’s effective date. The 2023 amendments plainly require a court creating such a first-instance plan to impose the rebuttable presumption that equal timesharing is in the child’s best interests, so the statute applies. The analysis of this situation does not get beyond step 1 of the retroactivity analysis.

If, however, a court is considering whether the rebuttable presumption in favor of equal timesharing applies to a modification of an existing parenting plan that predates the amendment’s effective date, this presents a second, more complicated, permutation. By its very nature, a modification plan is not a de novo proceeding, but rather an adjustment to a pre-existing parenting plan. Whether that pre-existing parenting plan is itself a first-instance plan or a modification plan based on an earlier first-instance plan does not matter for these purposes; the pre-existing parenting plan is a final judicial order that has res judicata effect.

Unlike the first permutation, the statutory text is not necessarily definitive in this second permutation. On the one hand, an effective-date provision is strong evidence against retroactivity and in favor of leaving the presumption of prospective application undisturbed. In this view, the 2023 amendment lacks the clear indicia of retroactivity that Florida law requires. On the other hand, the effective-date provision could be taken as a statement of intent for the amendment to apply to all parenting plans from that day forward, regardless of whether they are first-instance plans or modification plans. In this view, there is a clear statement of intent to apply the amendment to all timesharing schedules and impose the equal timesharing presumption irrespective of the court’s previous determination of the child’s best interests.

It is worth noting that the 2023 amendments did not invalidate any existing parenting plans and impose an equal timesharing presumption on them, suggesting the legislature did not intend to impose across-the-board retroactive application. Invalidating every existing parenting plan in the state would have proven enormously disruptive, so it is not difficult to imagine why the legislature might have chosen not to do this. Nevertheless, if the legislature intended retroactive application of the equal timesharing presumption to pre-existing parenting plans, one would expect the legislature to have made some substantive provision for doing so without waiting for someone to petition for modification.^[26]

Assuming the 2023 amendment provides for retroactive application and clears the hurdle of step 1 in this second permutation, there remains the matter of whether the amendment creates a new obligation or impairs a vested right.

Although one could view the 2023 amendment as affecting only the means by which timesharing rights are assigned, this would overlook the nature of modification proceedings and the res judicata effect of a pre-existing parenting plan. As explained above, the question in a modification proceeding before the 2023 amendment was whether a particular adjustment to an existing parenting plan was justified by a substantial change in circumstances and would be in the best interest of the child. Because the pre-existing parenting plan was res judicata, there had to be a substantial change in circumstances to justify changing it, and the specific modifications made to the plan had to serve the child’s best interests.

The 2023 amendment, however, effectively wipes away the res judicata effect of the pre-existing parenting plan and resets it to zero once a substantial change in circumstances is shown. Instead of asking what change to the prior plan will best serve the child’s interests, the 2023 amendment requires a court to assume that equal timesharing is best, irrespective of any prior findings, and for the parties to then prove by a preponderance of the evidence that any departures from equal timesharing are in the child’s best interests; including any prior findings that would not be disturbed by the particular change in circumstances giving rise to the modification. That is, having once proven that something was in the child’s best interests, the 2023 amendment requires the parties to prove it all over again, even if those aspects of the parenting plan have not been affected by any substantial change in circumstances.

Again, it is perhaps tempting to respond, “So what?” The fact that a party proved something once strongly suggests they can prove it again. But this overlooks the reality of the degradation of evidence over time: memories fade, witnesses become unavailable, documents are damaged or destroyed or simply put away and forgotten about. Proving a thing takes time and resources. The point of res judicata is that it excuses the parties to a controversy and the court system itself from needing to retrace their steps in this way. It gives the parties one chance to prove their case, and excuses them from the costs of holding themselves in perpetual readiness to prove it all over again. It also lightens the burden on the court system by ensuring that a decision, once made, stays made.

Properly understood then, applying the 2023 amendment’s equal timesharing presumption in a proceeding to modify a parenting plan that predates the amendment’s effective date would indeed be a retroactive, substantive change. Furthermore, removing the res judicata effect of a final judicial order is the alteration of a vested right. Florida law teaches that “when a final decree…becomes absolute it puts at rest and entombs in eternal quiescence every justiciable, as well as every actually adjudicated, issue.”^[27] The res judicata effect of a judgment is a vested right that a party is entitled to rely on. A substantial change in circumstances permits modification for the limited purpose of bringing the judgment in line with the changed circumstances.^[28] It has not, however, been a vehicle to wipe the slate of the prior judgment completely clean as a default option. Therefore, the 2023 amendment should not be applied retroactively.

Although Florida’s jurisprudence on the interplay between statutory retroactivity and the modification of parenting plans is somewhat thin, there are precedents supporting the conclusion that the 2023 amendment should not be applied retroactively in proceedings to modify parenting plans that predate its effective date. In Hahn v. Hahn, 42 So. 3d 945 (Fla. 4th DCA 2010), the Fourth District Court of Appeal considered whether to apply 2008 amendments to a 2007 petition to modify a 2005 parenting plan.^[29] The Hahn court concluded the amendments in question could not be applied retroactively. The Second District Court of Appeal reached a similar conclusion in Bachman v. McLinn, 665 So. 3d 71 (Fla. 2d DCA 2011), although it reasoned the retroactive application at issue in that case would impair contractual rights — presumably because the final judgment incorporated a marital settlement agreement.^[30] The Bachman court did expressly conclude, however, “that the legislature did not intend the retroactive application to child custody judgments which became final before the effective date of the legislation.”^[31]

It must be said that Hahn stands on a somewhat uncertain foundation. It relies in part on Poole v. Savage, 561 So. 2d 360, 363 (Fla. 1st DCA 1990), a First District case holding that “[§]61.13 has no retroactive application.”^[32] Poole in turn relies on Malchiodi v. Malchiodi, 431 So. 2d 301 (Fla. 3d DCA 1983), which simply states: “The Shared Parental Responsibility Act — Chapter 82-96, Florida Laws — which took effect July 1, 1982, has no retroactive application to child custody judgments which became final prior to July 1, 1982.” It is tempting to take this and run with it, and argue that any amendment to §61.13 that is not purely procedural and remedial would never apply retroactively to pre-existing parenting plans; but that seems to oversimplify the inquiry. No case goes so far as to impose a per se rule to this effect. These cases are, however, consistent with the conclusion that the 2023 amendment should not apply retroactively.

Conclusion

Taken altogether, the relevant elements of Florida law strongly suggest the equal timesharing provision of the 2023 amendments to §61.13 should not apply in proceedings to modify existing parenting plans established before the amendment’s effective date. The question demands a nuanced analysis, and it reveals interesting subsidiary questions that Florida law may be required to explore when the correct circumstances arise.

This column is submitted on behalf of the Family Law Section, Aimee Gross, chair, and Meghan McDonough, editor.