Lee's Summit Modification Attorney
Changing a Custody, Parenting Time or Support Judgment

by Kirby L. Minor — 20 years in the Independence courthouse

A judgment is not permanent, but it is not casually revisited either. Missouri sets a deliberately high bar for reopening a custody or support decree, and the bar is different depending on which one you are trying to change. A large share of the modification cases I see fail on that distinction rather than on the facts.

I handle post-judgment modifications in Jackson County and the surrounding counties, including cases where I did not handle the original decree.

Custody modifications are harder than support modifications

They are governed by different statutes with different standards, and people routinely apply the easier one to the harder problem.

For custody, Section 452.410.1 requires that the court have jurisdiction under Section 452.745 and find, on facts that have arisen since the prior decree or that were unknown to the court at the time, that a change has occurred in the circumstances of the child or the child's custodian, and that modification is necessary to serve the best interests of the child.

Read that carefully, because the limitation is easy to miss. The change has to be in the circumstances of the child or the custodian. A change in the non-custodial parent's circumstances — a better job, a new house, more availability, genuine improvement — does not by itself satisfy the statute. That is the most common reason a sincere and sympathetic modification petition fails.

One procedural point worth knowing: under Section 452.410.2, either parent filing to modify joint legal or joint physical custody is entitled to a change of judge as of right under Supreme Court rule. See Relocation and Custody Modifications for the custody side in depth, and Lee's Summit Child Custody Attorney for how custody is decided in the first place.

Support modifications, and the twenty percent rule

Section 452.370.1 sets a different standard: changed circumstances so substantial and continuing as to make the terms unreasonable.

The practical shortcut is the twenty percent rule. If running the current guidelines would change the support figure by twenty percent or more, that is a prima facie showing of a substantial and continuing change — provided the existing amount was based on the presumed guideline amount in the first place. Twenty percent is the only threshold the statute contains. There is no dollar-figure alternative.

Maintenance follows the same substantial and continuing standard. Note that under Section 452.370.3, unless the parties agreed otherwise in writing or the judgment expressly provides otherwise, the obligation to pay future statutory maintenance terminates on the death of either party or on the remarriage of the party receiving it. Lee's Summit Child Support Attorney covers the calculation itself.

Relocation has its own statute and its own clock

If a parent intends to move a child's principal residence, Section 452.377 governs, and it is unforgiving about deadlines.

A relocation is a change in the child's principal residence for ninety days or more. It is not defined by distance — a move across town for more than ninety days is a relocation under the statute.

The moving parent must give written notice by certified mail, return receipt requested, at least sixty days in advance, and the notice must contain six specific items: the intended new address, the new home phone number if known, the date of the intended move, a brief statement of the reasons, a proposed revised schedule of custody or visitation, and a statement of the other party's right to object.

The other parent then has thirty days from receipt to file a motion to prevent the relocation, supported by an affidavit setting out the specific good-faith factual basis. The relocating party has fourteen days to respond. If no motion is filed within thirty days, the relocation may proceed once the sixty days run.

The burden is on the party seeking to relocate, who must prove the move is made in good faith and is in the best interest of the child — both, not either.

Two consequences of skipping the process. Under Section 452.377.6, failure to give notice may be treated as a factor in modifying custody, as a basis to order the child returned, and as sufficient cause to order the relocating parent to pay the objecting party's reasonable expenses and attorney fees. And under Section 452.377.14, violating the section or an order under it may be deemed a change of circumstance under Section 452.410 — which is to say, it can supply the very ground for a custody modification against you.

There is a counterweight worth knowing if you are the one objecting: under Section 452.377.15, a party who objects in good faith is not to be ordered to pay the relocating party's costs and fees.

Filing in the right court, on the right papers

Modifications are generally filed in the court that entered the original judgment, which for most of my clients means Jackson County at Independence. Where the other party and the child have moved out of state, jurisdiction becomes its own threshold question under Section 452.745 and has to be resolved before anything else.

Jackson County requires updated financial disclosure on a modification touching support: Form 1402B and Form 1402A under Local Rule 68.4. Where minor children are involved, expect the FOCIS class under Local Rule 68.13 and the two-hour mediation minimum under Local Rule 68.12. The filing fee for a motion to modify is $144.50 on the current schedule.

When the modification is high-conflict

Some modifications are not really disagreements about a schedule. They are campaigns. The other parent files motions that go nowhere, raises allegations that do not survive contact with the evidence, cancels exchanges and documents none of it, or keeps a relocation half-announced. The object is not to win a hearing. It is to exhaust you.

Those cases are won by discipline rather than volume, and there are four things I tell a client at the outset.

Keep the objective fixed. The statute decides this case on the Section 452.375.2 factors and, for custody, on the Section 452.410.1 threshold. Every filing, every exhibit, and every email you send should be traceable to one of them. Motions filed to make a point cost money and give the court a reason to see you as half the problem. The objective is a judgment you can live under for the next decade, not the other parent’s defeat.

Prepare against chance. You do not choose your judge, your guardian ad litem, or what a child says when the court hears from them. What you can control is that nothing surprises you — full discovery, school and medical records, third-party witnesses, and an evaluation where alienation is genuinely in play. Preparation is the only reliable answer to a courtroom you do not control.

Know what actually decides the case. In most high-conflict modifications it is credibility. A parent who has spent a year telling a story the documents contradict loses on the documents. That is why a dated, unemotional log of missed exchanges, cancelled calls and refused decisions is worth more than any argument I can make for you — and why the reactive text sent at eleven at night is one of the most common ways a strong case gets damaged by the person holding it.

Know when to stop. Missouri starts from a presumption of equal or approximately equal parenting time, rebuttable only by a preponderance. Pushing past a sound result toward sole custody or no contact usually turns a winnable case into an expensive one and invites the court to discount what you have already proven. Take the decisive gain — the schedule, the enforceable boundaries, the decision-making structure — and consolidate it.

Clausewitz wrote that war is the continuation of policy by other means, and that the side which best masters uncertainty and friction is the side that prevails. A custody case is not a war. But the discipline transfers exactly: fix the objective, prepare ruthlessly, strike at what actually decides the case, and stop at the point where more fighting costs more than it gains.

What Clients Say

Literally the best lawyer! I hired Kirby after my divorced had been finalized with a previous lawyer and I wish I would have hired him off the bat. He is amazing, will fight for you, is super knowledgeable, and timely in responses! (Courtney Z.)

I recommend Kirby to everyone! I used him for my divorce and he helped me every step of the way. I have had to consult with him about a few issues even after the divorce and each time he has kept me calm and has been on top of everything. I feel so blessed to have him as my lawyer and would trust him with anything! (Laken G.)

Kirby was amazing and took on my case when I thought I had no hope. He worked hard and continues to support my journey. I highly recommend him! The best feeling when you are in this position is knowing you have someone that will fight for what is right and someone that is truly in your corner. I wish there was more than 5 stars!! (Kate J.)

Kirby and his law office were amazing! He always responded promptly and professionally. Going through a divorce is emotionally taxing... If you want to at least feel the burdens of getting divorced lifted from your shoulders I highly recommend Kirby. His prices were very affordable. During a trying time he will help alleviate some of the burden and fight for you! (Liz B.)

Move before the pattern hardens

Modification relief is not retroactive to the day your circumstances changed. On a support order you cannot pay, the court can reach only installments accruing after the date of personal service, so every month of delay is money you will not recover. On a custody arrangement that is failing, delay does something worse — it establishes a status quo, and courts are reluctant to disturb an arrangement a child has settled into, however it came about.

If something has genuinely changed, the question is not whether to act but whether what changed meets the standard. That is a half-hour conversation, not a leap of faith.

A thirty-minute phone consultation is $100. I will tell you plainly whether you have a modification worth filing, including when the answer is that you do not.

​

When the other parent fights everything

Some modification cases are not really about the change in circumstances. They are about a parent who will contest every filing, miss every exchange, and answer every motion with one of their own. Those cases are won on preparation and on staying pointed at the same objective from the first filing to the judgment.

​

Know which standard actually applies. Custody and support modifications are governed by different statutes, and the difference matters. A custody modification under § 452.410.1 RSMo requires facts that have arisen since the prior decree or were unknown to the court at the time, a change in the circumstances of the child or the custodian, and that modification is necessary to serve the child's best interests. A support or maintenance modification under § 452.370.1 RSMo is the "changed circumstances so substantial and continuing as to make the terms unreasonable" test, with the twenty-percent-deviation rule available as prima facie proof. Arguing the wrong standard is a common and expensive mistake.

​

Fix the objective and do not move off it. The court decides custody on the eight factors in § 452.375.2, against the rebuttable presumption that equal parenting time is in the child's best interests. Every exhibit, every deposition question, and every motion should map to one of those factors. A filing that exists to punish the other parent — rather than to prove a factor — costs money, delays the case, and reads badly from the bench.

​

Cut the uncertainty before the hearing. High-conflict cases run on incomplete information. Pull the records that exist: school attendance, medical, messaging and exchange logs, the other parent's own social media. Build more than one path to each fact you need, because one witness gets sick and one document goes missing. Preparation is what converts a contested hearing from a coin flip into an argument you already know the shape of.

​

Move early and control the temporary order. The temporary order sets the pattern the court sees for the rest of the case, and patterns are hard to undo. It also matters for money: on support, § 452.370.6 RSMo lets the court reach only installments that accrue after the date of personal service. Delay in getting the other party served is money you do not get back.

​

Know what winning looks like, and stop there. Missouri courts favor both parents staying involved. Pushing for sole custody or no contact, in a case where the facts do not support it, tends to cost credibility on everything else you asked for. The order worth having is one that is specific enough to enforce and durable enough that you are not back in six months.

​

If you are facing a contested modification in Jackson County, call or text 816-888-0632.

​