How to modify child support or alimony in South Carolina

Sources last checked: 4 November 2026. Information only, not legal advice. The Cusp is not a law firm.

South Carolina divorce kit How child support is calculated Alimony in South Carolina Legal aid in South Carolina After your divorce

The short version

In South Carolina, the family court can change child support under section 63-17-310 of the Code of Laws “upon a showing of changed circumstances”, and a change is not effective for any installment that came due before the modification action was filed and served. For periodic alimony, section 20-3-170 lets either spouse apply to the court that issued the divorce judgment for an order decreasing, increasing or ending the payments. The state’s Department of Social Services (DSS) publishes a Request for Modification Review (DSS Form 27129, May 2025 version) for cases handled by its Child Support Services Division. We could not read the South Carolina court system’s own forms or rules, because its website tells automated readers not to visit (see the end of this page).

What a request can ask for

Child support: section 63-17-310 gives the family court the right to modify a child support order “as the court considers necessary” on a showing of changed circumstances. The statute does not define the phrase.
The guidelines alone are not enough: section 63-17-470(B) says applying the guidelines to an existing order is not, in itself, a change in circumstances, except in a Title IV-D case. Section 63-17-470(C) lists factors, such as educational expenses, unreimbursed extraordinary medical expenses, support for other dependents and alimony, that the court considers as reasons to depart from the guidelines or in deciding whether a change in circumstances has occurred.
The reasons DSS lists: DSS Form 27129 offers two bases for a review: that more than 36 months have passed since the order was last issued, modified or reviewed, or a substantial and material change in circumstances. The changes it lists are a substantial increase or involuntary decrease in either party’s income, an older child becoming emancipated, a change of custody, a court-ordered visitation change to 109 or more overnights for the non-custodial parent, an additional child in the household, changed work-related childcare costs, and changed health insurance or health care needs.
Periodic alimony: section 20-3-130(B)(1) describes periodic alimony as ending on the supported spouse’s remarriage or continued cohabitation or either spouse’s death, and as “terminable and modifiable based upon changed circumstances” in the future. Section 20-3-170(A) says the court may decrease, increase, confirm or terminate the payments after hearing both parties, with due regard to the changed circumstances and the financial ability of the supporting spouse.
Other kinds of alimony: under section 20-3-130(B), separate maintenance and support is also modifiable on changed circumstances, rehabilitative alimony is modifiable on “unforeseen events” of the kinds the statute describes, and lump-sum and reimbursement alimony are “not terminable or modifiable based upon” changed circumstances. Section 20-3-130(G) lets parties agree in writing, with court approval, to make alimony nonmodifiable.
Retirement: section 20-3-170(B) says retirement by the supporting spouse is sufficient grounds for a hearing, if a party asks, on whether circumstances have changed. The court considers whether retirement was contemplated when alimony was awarded, the supporting spouse’s age and health, whether the retirement is mandatory or voluntary, and whether income would fall.

What else you file

Request for Modification Review (DSS Form 27129, May 2025 version): DSS says its forms are “for child support cases involving the Child Support Services Division”. If that division is not involved in your case, DSS tells you to contact your county Family Court about what forms it accepts. The form needs a copy of a photo ID. Its second page lists documents DSS requires for each kind of change, for example a letter from the Social Security Administration for disability benefits, a birth certificate for a new child, or a letter from a childcare provider plus receipts.
How to send it: DSS says to return the form by email to CSSDocuments@dss.sc.gov as a single PDF for a single case, or by mail to SCDSS-Child Support Services Division, PO Box 1469, Columbia, South Carolina 29202-1469, or by fax.
What DSS does with it: DSS says it can request updated financial information from both parents and review it. If a change is warranted it can make the change “administratively if there is agreement” between the parents, or present the case to a family court judge. DSS says it helps modify orders through the court “at no cost to you”. Its FAQ says either parent may ask the division to review an order every three years.
Court forms: we read no family court form for starting a modification case, and none for changing alimony. See the end of this page.

What the statutes say

The wording below is a plain-language summary of the South Carolina Code of Laws as shown on the Legislature’s website, and of the Department of Social Services child support guidelines regulation, all read on 4 November 2026, with short quotations.

No change for earlier installments, section 63-17-310: No modification is “effective as to any installment accruing prior to filing and service” of the action for modification. Filing alone is therefore not the whole test; service on the other side also counts. The statute does not say how service is made.
Guideline presumption, section 63-17-470(A): in a child support proceeding the amount under the guidelines is rebuttably presumed correct. A different amount may be awarded on a showing that applying the guidelines would be “unjust or inappropriate”, and the court must then make specific written findings.
The guidelines themselves: section 43-5-580(b) has DSS issue the guidelines by regulation. Regulation 114-4710 says the guidelines have an implementation date of January 1, 2024, and that deviation “should be the exception rather than the rule”.
Transfer between courts, section 63-17-320: a family court has authority to enforce or modify a support order of another court, subject to the limits of section 63-17-310. Either party may petition to transfer the case to the family court of the county where the other party lives, and the court of original jurisdiction decides in its discretion.
Alimony and cohabitation, sections 20-3-130(B) and 20-3-150: unless the parties agreed otherwise in writing, “continued cohabitation” means the supported spouse resides with another person in a romantic relationship for ninety or more consecutive days. The court may find continued cohabitation on shorter periods if the two periodically separate to avoid the ninety-day requirement.
Child maintenance in a divorce case, section 20-3-160: the court may make orders about the care, custody and maintenance of children “from time to time after final judgment”.

Notice, service and hearing

Service: section 63-17-310 makes filing and service the dates that matter for child support. The sources we read do not say how or by when the other party must be served.
Hearing for alimony: section 20-3-170(A) says the court acts “after giving both parties an opportunity to be heard” and to introduce evidence.
Where: section 20-3-170(A) says the application goes to the court that rendered the divorce judgment. For child support, section 63-17-320 provides for transfers to another county’s family court. We did not read the venue rules for a new modification case.

Before you file

Court staff cannot give legal advice. See legal aid in South Carolina for free or low-cost help, or the South Carolina divorce kit for the wider process.
Timing matters: because a child support change does not reach installments that came due before filing and service, act as soon as your circumstances change.
Check which kind of alimony your order provides. The statute treats periodic, rehabilitative, lump-sum, reimbursement and separate maintenance awards differently, and the decree may say alimony is nonmodifiable.
Gather proof of the change. DSS Form 27129 lists the documents DSS requires. We do not know what a family court requires.
Child support amounts follow the state guidelines. See how child support is calculated in South Carolina and alimony in South Carolina. For other changes after a divorce, see After your divorce.

What we could not confirm

Court forms and rules. The South Carolina Judicial Branch website (sccourts.org) publishes a robots.txt file that disallows every path for automated readers other than a few named search engines. We obey that file, so we read none of its forms, self-help pages or Family Court rules. We cannot name a court form for a child support or alimony modification case.
Filing fees and fee waivers. No fee appears in the sources we read, so this page states none.
Service and deadlines. We did not read the Rules of Civil Procedure or Family Court rules, so we do not say how to serve the other party or what deadlines apply.
What counts as changed circumstances. Neither section 63-17-310 nor section 20-3-170 defines it, and we read no court opinions, so we do not say how judges apply it.
Whether alimony changes can reach back before you file. Section 20-3-170 as we read it says nothing either way.
When DSS review applies. DSS says its forms are for cases involving its Child Support Services Division. We did not read DSS policy on which cases qualify, and we do not know whether the 36-month and 109-overnight criteria on Form 27129 bind a family court judge. They are DSS review criteria.
Guideline schedule and worksheets. We read only part of the regulation and give no support amounts.
Orders from another state or country. We did not read the interstate support provisions.
Later changes. We did not check for amendments to the Code or regulation after the versions posted on the dates above.
Local practice. We did not read any county’s procedures.

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