Connecticut courts will modify an existing child support order when either parent demonstrates a substantial change in circumstances or when the current order deviates by 15% or more from state guidelines. Under Connecticut General Statutes § 46b-86, the filing fee for a child support modification motion is $180, and modifications take effect from the date you file—not retroactively. The new Connecticut Child Support Guidelines taking effect August 1, 2026, expand coverage to net incomes up to $6,000 per week ($312,000 annually), which may trigger modification eligibility for many existing orders.
Key Facts: Connecticut Child Support Modification
| Requirement | Details |
|---|---|
| Filing Fee | $180 (as of April 2026; verify with local clerk) |
| Required Form | Form JD-FM-174 (Motion for Modification) |
| Legal Standard | Substantial change in circumstances OR 15% deviation from guidelines |
| Effective Date | Date of filing (not retroactive) |
| Three-Year Review | Available without proving substantial change |
| Governing Statute | C.G.S. § 46b-86 |
| Income Cap (2026) | $6,000/week net ($312,000/year) effective August 1, 2026 |
| Service Requirement | Serve opposing party at least 12 days before hearing |
What Qualifies as a Substantial Change in Circumstances
Connecticut courts require proof of a substantial change in circumstances before modifying child support, and under C.G.S. § 46b-86(a), a deviation of 15% or more between the existing order and the recalculated guidelines amount creates a rebuttable presumption that modification is warranted. This 15% threshold applies to the support amount itself, not the underlying income change—meaning a 25% salary increase might only shift child support by 12% depending on the formula calculation, which would not automatically qualify.
Connecticut courts recognize the following as substantial changes justifying child support modification:
- Job loss or significant income reduction (involuntary)
- Substantial income increase for either parent
- Disability affecting earning capacity
- Changes in parenting time or custody arrangements
- Child aging out of daycare (reducing childcare costs)
- Changes in health insurance costs or availability
- Addition or emancipation of children
- Relocation affecting transportation expenses
- Child's special needs or medical expenses changing
Importantly, Connecticut Supreme Court precedent establishes that remarriage alone does not constitute grounds for child support modification. Neither parent can reduce support simply because they have new family obligations or because their former spouse remarried. Additionally, voluntarily quitting your job or intentionally reducing your income will not justify a modification—courts look for involuntary and ongoing changes in circumstances.
The 15% Deviation Rule Explained
Connecticut uses a mathematical threshold to determine whether modification is warranted: if recalculating support using current guidelines produces an amount at least 15% higher or lower than the existing order, that deviation alone qualifies as a substantial change. Under C.G.S. § 46b-86(a), a deviation below 15% is presumed not substantial, though courts retain discretion in borderline cases.
For example, if your current child support order requires $1,000 per month and recalculating with today's incomes produces $1,150 or more (15% increase) or $850 or less (15% decrease), you have met the threshold. This rule allows parents to seek modification based purely on changed economic circumstances without proving a dramatic life event occurred.
The 2026 guideline updates taking effect August 1, 2026, may affect this calculation significantly. The new guidelines expand the schedule to cover net incomes up to $6,000 per week ($312,000 annually) compared to the previous $4,000 weekly cap. If either parent's income now falls within this expanded range, recalculation under the new guidelines may produce a 15% or greater deviation from existing orders.
How to File for Child Support Modification in Connecticut
Filing a child support modification motion in Connecticut requires completing Form JD-FM-174 (Motion for Modification) and submitting it to the Superior Court that issued the original order. The filing fee is $180 as of April 2026—verify current fees with your local clerk before filing. Fee waivers are available through Form JD-FM-75 for individuals receiving SNAP, TFA/TANF, Medicaid, or Title XIX assistance, or for those earning below 125% of the federal poverty level.
Required Documents for Filing
- Form JD-FM-174 (Motion for Modification)
- Form JD-FM-6 (Financial Affidavit) — must be filed at least 5 business days before hearing
- Form CCSG-1 (Connecticut Child Support and Arrearage Guidelines Worksheet)
- Form JD-FM-164 (Affidavit Concerning Children)
- Advisement of Rights Re: Income Withholding
- Documentation supporting your claimed change in circumstances
Service Requirements
You must serve a true and attested copy of the Motion for Modification and the Order on the opposing party at least 12 days before the scheduled court event. Proof of service must be filed with the court at least 6 days before the hearing date. Proper service is essential—failure to comply may result in your motion being dismissed or continued.
Special Filing Requirements for State Assistance Cases
If you are receiving state assistance, HUSKY health insurance, or have received it in the past, or if any child subject to the motion receives these benefits, you must send a copy of the motion to: The Office of the Attorney General, 55 Elm Street, Hartford, CT 06106. Failure to provide this notice may delay your case. Additionally, when one party has applied for child support enforcement services under Title IV-D of the Social Security Act, the modification motion must be filed with the Family Support Magistrate Division rather than regular Superior Court.
The Three-Year Review Option
Connecticut offers an alternative pathway to child support modification that does not require proving a substantial change in circumstances. Either parent may request a review of the child support order every three years through Support Enforcement Services (SES). This federally mandated review assesses whether the current order conforms to current Connecticut Child Support Guidelines and may result in modification if significant deviation exists.
The three-year review is particularly useful when both parents' incomes have changed gradually over time without any single dramatic event. Rather than proving job loss or disability, parents can simply demonstrate that the existing order no longer reflects current financial realities. Contact Support Enforcement Services at 1-800-228-KIDS (5437) to request a three-year review.
Connecticut Child Support Enforcement Services
The Connecticut Child Support Enforcement Program (the IV-D program) operates as a cooperative effort between the Judicial and Executive Branches. The Support Enforcement Services Unit handles monitoring child support awards, initiating court-based enforcement actions such as income withholdings and contempt applications, reviewing financial support orders, and initiating modifications when orders substantially deviate from guidelines.
Services available through Connecticut Support Enforcement include:
- Case monitoring and payment tracking
- Income withholding order enforcement
- License suspension for non-payment
- Tax refund interception
- Contempt actions for willful non-payment
- Interstate enforcement under UIFSA
- Periodic review and modification assistance
Contact the Support Enforcement Services Child Support Call Center at 1-800-228-KIDS (5437) for cases filed through DSS. For payment processing and payment information, call 1-888-233-7223. The Bureau of Child Support Enforcement is located at 25 Sigourney Street, Hartford, CT 06106-5033.
Income Withholding for Child Support
Since 1988, all Connecticut court orders for child support include an automatic income withholding order under C.G.S. § 52-362. Once the court issues or modifies a child support order, the court or custodial parent sends a copy to the employer, who must withhold the ordered amount from each paycheck. Employers must remit withheld payments to the State Disbursement Unit within 7 business days.
Federal law limits the maximum amount that can be garnished for child support based on the employee's circumstances:
| Situation | Maximum Withholding |
|---|---|
| Supporting another spouse/child | 50% of disposable earnings |
| Not supporting another spouse/child | 60% of disposable earnings |
| 12+ weeks in arrears (additional) | +5% (up to 55% or 65% total) |
Employees cannot be fired, disciplined, or retaliated against because their wages are subject to a child support withholding order. If your employer fails to withhold as directed, they become liable for the accumulated amount they should have withheld.
When Child Support Ends in Connecticut
Under Connecticut law, child support typically terminates when the child reaches age 18 or graduates from high school, whichever occurs later. If the child is still in high school at age 18, support continues until graduation or age 19, whichever comes first. The age 19 cutoff is absolute—support stops at 19 regardless of whether the child is still in school.
Child support may terminate earlier through emancipation, which occurs when a minor becomes financially independent before reaching the age of majority. Emancipation can result from marriage, military enlistment, or full-time employment with demonstrated self-sufficiency. Military enlistment emancipates minors immediately and terminates support obligations.
Connecticut courts cannot order parents to pay for college education without parental agreement. Under C.G.S. § 46b-66, parties may voluntarily agree that support obligations extend beyond age 18 as part of a divorce settlement, and such agreements can be incorporated into the divorce decree and enforced through contempt proceedings. However, absent such an agreement, the court's power to order support ends when the child reaches majority.
Modifications Are Not Retroactive
Critically, child support modifications in Connecticut take effect from the date you file the motion—not from the date circumstances changed. Under C.G.S. § 46b-86, no order for periodic payment of support may be subject to retroactive modification, except that the court may order modification with respect to any period during which there is a pending motion for modification from the date of service of notice upon the opposing party.
This rule creates urgency for parents experiencing changed circumstances. If you lose your job today but wait six months to file for modification, the court cannot go back and adjust the payments you owed during those six months. You remain responsible for the full original amount until your motion is filed and the other party is properly served. The practical implication: file promptly when circumstances change.
Major 2026 Child Support Guideline Changes
Connecticut's Commission for Child Support Guidelines has approved major revisions taking effect August 1, 2026, that may affect modification calculations. These changes represent the most significant update to Connecticut child support guidelines in years.
Key changes include:
- Income cap expansion from $4,000/week to $6,000/week net ($312,000 annually)
- New framework for calculating support with more than two legally recognized parents
- Updated arrearage guidelines affecting how back support is calculated
- Adjusted treatment of Social Security Disability benefits for arrears calculations
The expanded income cap is particularly significant. Previously, parents with combined net incomes exceeding $4,000 per week fell outside the guidelines table, leaving courts with substantial discretion. The new $6,000 weekly cap provides clearer guidance for higher-income families and may result in different support calculations.
These changes do not automatically modify existing orders. However, if recalculating under the new guidelines produces a 15% or greater deviation from your current order, you may have grounds for modification after August 1, 2026.
Increase vs. Decrease: Who Can File
Either parent may file a motion to modify child support in Connecticut—the custodial parent seeking an increase or the non-custodial parent seeking a decrease. The legal standard remains the same: demonstrate a substantial change in circumstances or a 15% deviation from current guidelines.
Parents seeking to increase child support typically cite:
- Paying parent's income has substantially increased
- Child's needs have increased (medical, educational, extracurricular)
- Custodial parent's income has decreased
- Childcare or health insurance costs have risen significantly
Parents seeking to decrease child support typically cite:
- Job loss or involuntary income reduction
- Disability affecting earning capacity
- Receiving parent's income has substantially increased
- Increased parenting time reducing need for payments
- Child's needs have decreased (aged out of daycare, medical condition resolved)
Remember: voluntary unemployment or underemployment will not justify a decrease. Connecticut courts impute income to parents who deliberately reduce their earnings to avoid support obligations.
Frequently Asked Questions
How much does it cost to modify child support in Connecticut?
The filing fee for a child support modification motion in Connecticut is $180 as of April 2026. Fee waivers are available through Form JD-FM-75 for individuals receiving public assistance (SNAP, TFA/TANF, Medicaid) or earning below 125% of the federal poverty level. Additional costs may include attorney fees and service of process expenses.
Can I modify child support without going to court in Connecticut?
Yes, either parent can request a three-year review through Support Enforcement Services (1-800-228-KIDS) without filing a court motion. This administrative review assesses whether the current order deviates from guidelines and may result in modification. However, if either parent contests the review results, the matter proceeds to court.
What is the 15% rule for Connecticut child support modification?
Under C.G.S. § 46b-86(a), if recalculating child support using current guidelines produces an amount at least 15% higher or lower than the existing order, that deviation alone creates a rebuttable presumption that modification is warranted. A deviation below 15% is presumed not substantial, though courts have discretion in borderline cases.
How long does a child support modification take in Connecticut?
Child support modification cases typically take 2-4 months from filing to final order, depending on court scheduling and whether the matter is contested. You must serve the opposing party at least 12 days before the hearing, and file proof of service at least 6 days before. Complex cases involving disputed income or custody issues may take longer.
Can child support be modified retroactively in Connecticut?
No. Under C.G.S. § 46b-86, child support modifications take effect from the date of filing—not retroactively to when circumstances changed. The only exception allows modification back to the date of service of the pending motion. File promptly when circumstances change to minimize the period at the old support amount.
Does remarriage affect child support in Connecticut?
Remarriage alone does not constitute grounds for child support modification under Connecticut Supreme Court precedent. Neither parent can reduce support simply because they have new family obligations or because their former spouse remarried. However, remarriage that substantially changes household income may be considered as part of the overall financial picture.
What happens if I lose my job in Connecticut?
Job loss qualifies as a substantial change in circumstances for child support modification, but only if the job loss was involuntary. File Form JD-FM-174 immediately—modifications are not retroactive, so you remain responsible for the full original amount until your motion is filed. Voluntarily quitting or being fired for cause may not justify modification.
When does child support end in Connecticut?
Connecticut child support terminates when the child reaches age 18 or graduates from high school, whichever occurs later, with an absolute cutoff at age 19. Support may end earlier through emancipation (marriage, military service, full-time employment). Courts cannot order college support without parental agreement under C.G.S. § 46b-66.
Can I change child support if my ex's income increased?
Yes. If the paying parent's income has substantially increased since the original order, you may file for modification. Recalculate support using the Connecticut Child Support Guidelines Worksheet (Form CCSG-1) with updated income figures. If the new calculation produces a 15% or greater increase from the current order, you have met the threshold for modification.
Where do I file for child support modification in Connecticut?
File your modification motion in the Superior Court that issued the original child support order. If you or your child receives state assistance (HUSKY, TFA/TANF) or you have applied for IV-D child support enforcement services, file with the Family Support Magistrate Division instead. Send a copy to the Office of the Attorney General if public benefits are involved.