Guide to Modifications in Jackson County, Missouri

The two standards, and why people file the wrong case

Missouri does not have one modification standard. It has two, and they are not close to each other.

Custody is governed by Section 452.410.1. A court cannot modify a prior custody decree unless it finds, on facts that have arisen since the decree or that were unknown to the court when it was entered, 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.

Child support and maintenance are governed by Section 452.370.1, which requires a showing of changed circumstances so substantial and continuing as to make the existing terms unreasonable.

Both sound like "something changed." They are not the same test, they are not proven with the same evidence, and a motion that recites the wrong one invites a motion to dismiss before anyone reaches the merits.

Most of the modification cases I see that go badly went badly at this step.

What counts as a change in circumstances — and what does not

Read Section 452.410.1 again and notice whose circumstances matter: the child, or the child's custodian. That is the whole list.

This is where most people are surprised. A parent who has gotten sober, gotten a better job, moved into a bigger house, remarried into stability, or finally gotten their life together has not, by doing those things, created a change in circumstances that supports modifying custody. The improvement is real and it matters to how a court sees that parent. It is not, standing alone, the statutory predicate.

What does tend to support a custody modification:

A change in the child's circumstances — school failure, a medical or mental health development, a safety issue, the child's situation in the custodial household deteriorating.
A change in the custodial parent's circumstances — instability, a new household member who presents a problem, substance abuse, a pattern of withholding the child, an intended relocation.
Facts that existed at the time of the decree but were concealed from or unknown to the court.

And "necessary to serve the best interests of the child" is a second hurdle, not a restatement of the first. A court can find a change occurred and still decline to modify because modification is not necessary. The eight statutory best-interest factors under Section 452.375.2 are how that second question gets answered.

Parenting time is easier to change than custody

This is the most useful thing on this page, and it is the thing most people calling me do not know.

Modifying custody requires the 452.410.1 showing. Modifying the parenting time schedule does not. Under Section 452.400.2 a court may modify visitation whenever modification would serve the best interests of the child — no substantial change required. The higher bar attaches to restricting parenting time, which requires a finding that the visitation would endanger the child's physical health or impair the child's emotional development.

So there are two very different cases:

"I want to be the primary custodian instead of her." That is a custody modification, and it is hard.
"The schedule we have does not work anymore and I want more time." That is a parenting time modification, and the standard is best interests.

People file the first when what they actually want, and can actually get, is the second. If your real complaint is that the schedule is bad rather than that the child is in the wrong home, say so out loud, because it changes the case you file, the evidence you need, and what it costs.

Child support and the twenty percent rule

Under Section 452.370.1, a prima facie showing of a substantial and continuing change is made when applying the child support guidelines to the financial information available to the court would produce a support amount differing from the existing amount by twenty percent or more.

Practically, that means the first thing to do is not to write a motion. It is to run a current Form 14. If the new presumed amount is inside twenty percent of the existing order, you are not automatically out — but you are arguing the general standard rather than pointing at a number, and you should know that going in.

Things that commonly move the number: a real and lasting change in either parent's income, a change in which parent pays health insurance or work-related child care, a change in overnights that affects the line 11 adjustment, and a child aging out.

Things that commonly do not move it as much as people expect: a raise that is offset by the other parent's raise, a voluntary reduction in income, and overtime that cannot be shown to be steady.

Maintenance

Maintenance modification runs on the same 452.370.1 standard — substantial and continuing change making the terms unreasonable.

Two things worth knowing before you spend money on it. First, if your judgment or separation agreement made maintenance non-modifiable, that is generally the end of the analysis, and it is the first thing I look for. Second, retirement, a new job at lower pay, or a recipient's remarriage or cohabitation are the fact patterns that most often support a motion — but each of them is fact-intensive, and the outcome depends on what your particular judgment says.

Relocation is its own statute

If the issue is a parent moving, you are not primarily in 452.410 at all. You are in Section 452.377, which runs on notice and deadlines rather than on the general modification standard.

The moving parent must give written notice by certified mail, at least sixty days in advance, containing specific information the statute requires — the intended new address, the home telephone number, the date of the intended move, a statement of the specific reasons for the move, and a proposal for a revised schedule of custody or visitation.

The other parent has a limited window to file a written objection, and failing to object on time is how people lose relocation cases without a hearing.

Relocation is the one modification issue where the calendar can decide the outcome before the facts do. If you have received a notice, or you are thinking about sending one, that is a call worth making the same week.

What a modification actually looks like in Jackson County

A modification is a new case with a new case number, filed in the court that entered the original judgment, and it moves much the way the original did: motion, service, answer, case management conference, discovery, often mediation, then settlement or trial.

The practical differences from an original case are worth planning around. The record already exists, so discovery tends to be narrower and more targeted. The judge may be the one who entered the judgment you are asking to change. And a guardian ad litem may be appointed again if custody is genuinely contested.

Where a child's safety cannot wait for that schedule, the question is not modification but emergency relief, which is a different filing on a different timeline.

Modification or appeal?

These get confused, and they are opposites.

A modification says the judgment was right when it was entered and circumstances have since changed. An appeal says the judgment was wrong when it was entered and asks a higher court to say so on the record that already exists.

If you are within the window to appeal and the real complaint is that the judge got it wrong on the evidence presented, filing a modification is not a substitute — and the appellate deadline will not wait while a modification is pending.

Before you file, the questions I ask

What does the existing judgment actually say? Not what you remember agreeing to — what the signed judgment says.
What has changed, when did it change, and can you prove it with something other than your own testimony?
Whose circumstances changed — the child's, the custodial parent's, or yours?
Is the real problem custody, or is it the schedule?
Has a current Form 14 been run?
Is anyone moving, and has notice been sent or received?
Is there a safety issue that cannot wait?

If you can answer those, the consultation is worth the money. If you cannot, the first part of the consultation is getting the answers, which is fine too.

The initial consultation is $100 for 30 minutes.

Talk to me

If you have a Jackson, Cass, Clay or Johnson County judgment you are thinking about changing, call or text 816-888-0632. Bring the judgment.