The statutory test
Section 156.101 allows modification of conservatorship, possession or access where the circumstances of the child, a conservator or another party affected by the order have materially and substantially changed since the earlier of the date the order was rendered or the date the mediated settlement agreement was signed, and the modification would be in the child's best interest.
Both halves matter. A genuine change that is not in the child's best interest does not get you a modification, and a change that is plainly good for the child but was entirely foreseeable at the time of the last order may not clear the first hurdle either.
What courts have treated as enough
There is no statutory list, and the analysis is fact-intensive. In our experience in El Paso County, the following recur as the facts that carry a modification.
- A parent's relocation, or a move that makes the existing exchange schedule unworkable.
- A change in work schedule, particularly a move to nights or to a rotating roster.
- A new medical, educational or behavioural need in the child that the existing order does not address.
- A significant, involuntary and sustained change in either party's income, for support purposes.
- Remarriage or a change in household composition that materially affects the child's day-to-day life.
- A parent's sustained failure to exercise possession, or conduct endangering the child.
What is usually not enough on its own
Disliking the other parent's new partner. The child asking to change houses. A single missed exchange. General dissatisfaction with an order you agreed to eighteen months ago. A child turning twelve, without more.
Each of those can become part of a successful case when combined with something concrete and documented. None of them, standing alone, is a material and substantial change, and filing on one of them costs money and credibility.
The one-year affidavit gate
If you are asking to change who designates the child's primary residence within one year of the order, section 156.102 requires an affidavit with specific supporting facts: that the child's present environment may endanger their physical health or significantly impair their emotional development, that the person with the designation is the one seeking or consenting to the change, or that they have voluntarily relinquished primary care and possession for at least six months.
The judge reads the affidavit first. If it does not contain adequate facts, the case is dismissed without a hearing and without the other side ever filing anything. Vague affidavits are the single most common reason a modification suit ends before it begins.
Support has an easier route
Child support modification under section 156.401 offers a second path that does not require proving a material and substantial change at all. If three years have passed since the order was rendered or last modified, and the guideline amount now differs from the ordered amount by either twenty percent or one hundred dollars, that alone supports modification.
One practical warning: a support modification is generally effective from the date of service of the motion, not from the date your income actually changed. Every month you wait is a month at the old number that you will not get back. If your income has dropped, file now and negotiate afterwards.
