How to Modify Child Support in Texas

Child support orders in Texas are not permanent. When circumstances change significantly, either parent can petition the court to increase, decrease, or otherwise modify the existing order. Texas law provides specific standards for when and how modifications can occur, and understanding these rules is critical whether you are seeking a change or responding to one.

For a general overview of child support modification across the country, see our national guide on how to modify child support.

When Can You Modify Child Support in Texas?

Under Texas Family Code Section 156.401, a court may modify a child support order if one of the following conditions is met:

1. Material and Substantial Change in Circumstances

The most common basis for modification is proving a material and substantial change in the circumstances of the child, the person paying support (the obligor), or the person receiving support (the obligee) since the date of the last order.

Examples of changes that typically qualify include:

• Job loss or significant income reduction of the obligor (involuntary, not self-imposed)
• Substantial increase in the obligor’s income since the last order
• Change in the child’s needs, such as new medical conditions, educational requirements, or the child aging out of daycare
• Change in custody or possession — if the child begins living primarily with the other parent, the support obligation may need to change
• The obligor’s legal obligation to support additional children born since the last order
• The obligee remarrying or cohabitating, which may change the child’s household financial situation
• A child becoming emancipated, turning 18, or graduating from high school

The change must have occurred after the date of the existing order. Circumstances that existed at the time of the original order generally cannot be used as a basis for modification.

2. The Three-Year / $100 Rule

Texas provides an alternative ground for modification under TFC 156.401(a)(2). You can seek modification if:

• It has been at least three years since the order was last set or modified, and
• The monthly amount of support under the existing order differs by 20% or $100 from the amount that would be calculated under the current child support guidelines

This provision allows a parent to seek modification based solely on the passage of time and the updated guideline amount, without proving a separate material and substantial change. It is particularly useful when incomes have gradually changed over time or when the guidelines themselves have been updated.

How Texas Calculates Child Support

Texas uses a percentage-of-income model for calculating child support. Under TFC Chapter 154, the guideline amounts are based on the obligor’s net monthly resources:

Net resources include wages, salary, commissions, overtime, tips, bonuses, self-employment income, interest, dividends, rental income, retirement benefits, and most other forms of income, minus certain deductions (federal income tax, Social Security, Medicare, health insurance for the child, and union dues).

There is a statutory cap on the income subject to child support guidelines. As of recent years, the cap applies to the first $9,200 in net monthly resources (this amount is adjusted periodically). For obligors earning above the cap, the court may order additional support above the guideline amount if the child’s proven needs justify it.

For more detail on child support calculations nationally, see how is child support calculated.

How to File for a Child Support Modification

Option 1: Through the Texas Attorney General’s Office

The Texas Office of the Attorney General (OAG) Child Support Division can help parents file for child support modifications. The OAG provides this service at no cost to the parent.

The process typically involves:

1. Contacting the OAG to request a review of the existing order. You can do this online, by phone, or in person at a local child support office.
2. Providing documentation of changed circumstances or updated income information.
3. The OAG conducts a review and determines whether the order should be modified under the guidelines.
4. If both parties agree to the proposed change, the OAG prepares a modified order for the court to sign.
5. If the parties disagree, the OAG can file a motion to modify and represent the state’s interest at a court hearing.

Advantages of using the OAG:

• No attorney fees
• The OAG handles paperwork and court filings
• Accessible for parents who cannot afford private representation

Disadvantages:

• The OAG represents the state’s interest in supporting the child, not your individual interest
• Processing times can be longer
• The OAG may not advocate for your specific position on contested issues
• Complex cases involving business income, self-employment, or disputed finances may not receive the level of attention a private attorney would provide

Option 2: Through a Private Attorney

Hiring a private family law attorney to file a modification gives you dedicated legal representation focused on your interests. This is generally advisable when:

• The case involves complex income issues (self-employment, business ownership, stock options, irregular income)
• You need to challenge the other parent’s claimed income or expenses
• There are related custody or possession issues to address simultaneously
• The other parent is represented by an attorney
• You want to move quickly and cannot wait for the OAG’s timeline

The process with a private attorney involves:

1. Filing a Petition to Modify in the court that has continuing jurisdiction over the existing order (usually the court that issued the original order)
2. Serving the other parent with the petition
3. Exchanging financial information through discovery or informal disclosure
4. Negotiating a resolution or proceeding to a hearing before the judge
5. The court enters a modified order if the legal standard is met

Retroactivity

Under Texas Family Code Section 156.401(b), a modified child support order can be made retroactive to the date the petition to modify was filed, or to the date of the filing of a motion for enforcement that also seeks modification.

This means:

• If you file a petition to modify and the case takes several months to resolve, the modified amount may apply retroactively to the filing date
• You cannot get retroactive modification for periods before you filed. This is why filing promptly when circumstances change is important.

The court has discretion on whether to apply the modification retroactively and is not required to do so.

Medical Support

Texas child support orders include provisions for medical support in addition to the base cash support amount. Under TFC Chapter 154, Subchapter D, the court must address:

• Health insurance coverage for the child. The court typically orders the parent who has access to employer-sponsored health insurance at a reasonable cost to maintain coverage for the child.
• Cash medical support. If neither parent has access to affordable insurance, the court may order one or both parents to pay cash medical support to cover the cost of health insurance premiums.
• Uninsured medical expenses. The court allocates responsibility for medical expenses not covered by insurance, often splitting them between the parents.

When modifying child support, the medical support provisions can also be reviewed and adjusted.

TFC 156.401: The Full Legal Standard

For reference, Texas Family Code Section 156.401 provides the complete legal framework. A modification order must include findings that:

1. The circumstances of the child or a person affected by the order have materially and substantially changed since the date of the last order, or
2. It has been three years since the order was last modified (or since the order was originally rendered) and the monthly support amount differs by either 20% or $100 from the guideline amount based on current circumstances

The court applies the same child support guidelines (TFC Chapter 154) to calculate the appropriate modified amount, considering the obligor’s current net resources and the number of children.

For a complete overview of Texas family law, visit our Texas divorce guide. You may also find our guide on child support enforcement helpful if you are dealing with non-payment.

What to Do Next

If your circumstances have changed or it has been three or more years since your child support order was set, here is how to move forward:

1. Gather financial documentation. Collect recent pay stubs, tax returns, proof of income changes, and records of the child’s current expenses and needs.
2. Calculate the potential guideline amount. Compare the current order to what the Texas guidelines would produce based on updated income figures. If the difference is 20% or $100 or more, you may have grounds under the three-year rule.
3. Decide between the AG’s office and a private attorney. For straightforward cases, the OAG can be an effective option. For complex situations, a private attorney provides dedicated representation.
4. File promptly. Retroactive modification only goes back to the filing date. Delaying the filing means losing potential months of the corrected support amount.
5. Continue complying with the existing order. Do not stop paying or reduce payments without a court order. Non-compliance can result in enforcement actions, including contempt of court.

Schedule a free consultation to discuss your Texas child support modification with an experienced family law attorney.

Frequently Asked Questions

What are the two grounds for modifying child support in Texas?

Under TFC 156.401, you can modify if there has been a material and substantial change in circumstances (such as job loss, income increase, or change in the child’s needs), OR if three years have passed since the last order and the current guideline amount differs by 20% or $100 from the existing order. The three-year rule allows modification based solely on time and updated income without proving a separate dramatic change.

How does Texas calculate child support?

Texas uses a percentage-of-income model. The obligor pays 20% of net monthly resources for one child, 25% for two, 30% for three, 35% for four, and 40% for five. There is a statutory cap on the income subject to guidelines — approximately $9,200 in net monthly resources (adjusted periodically). For income above the cap, additional support requires proof of the child’s actual needs.

Should I use the Attorney General’s office or a private attorney to modify?

The OAG provides free modification services but represents the state’s interest in supporting the child, not your individual interest. Processing times can be longer and complex cases may not receive detailed attention. A private attorney is advisable for cases involving self-employment income, disputed finances, simultaneous custody issues, or when the other parent is represented by counsel.

Can a Texas modification be retroactive?

Yes. Under TFC 156.401(b), a modified order can be retroactive to the date the modification petition was filed. This means delays in filing cost you — every month before the filing date, the original order amount applies. If your income drops significantly, file immediately rather than waiting.

How This Guide Was Researched

This guide was created by reviewing publicly available legal information from official state statutes, judiciary websites, court resources, and family law publications. The goal is to explain family law topics in plain English so readers can better understand the process before speaking with an attorney.

Sources and Legal References

This guide is based on publicly available legal information and official sources, including:

• Texas state statutes and family law codes
• Texas judicial branch website and court resources
• Official Texas court forms and filing instructions
• Texas child support guideline publications
• State bar association and legal aid resources

Official Texas Resources

• Texas Law Help – Family, Divorce & Children
• Texas Courts – Self-Represented Litigants
• Texas State Law Library – Divorce Guide

For more about how we research our guides, see our editorial policy and sources methodology.

Related Guides

Learn more about related family law topics:

• Complete guide to divorce
• Child support guidelines by state
• Modifying child support
• How alimony works
• How to file for divorce
• Child support enforcement
• How to file for child support

Last updated: March 2026. This guide summarizes general legal information based on publicly available sources and is provided for educational purposes only. It does not constitute legal advice. For advice specific to your situation, consult a licensed attorney in your state.