What Counts as a Significant Variance for Child Support Modification in Tennessee
In Tennessee, child support can be modified when there is a significant variance: at least a 15% change from the proposed presumptive order, or 7.5% for a low-income provider. Health care needs are a separate basis.
What is a significant variance for child support in Tennessee?
The statute says that on either party’s application the court shall decree an increase or decrease of support when there is found to be a significant variance, as defined in the child support guidelines, between the guidelines and the amount currently ordered, unless the variance came from a previous court-ordered deviation whose circumstances have not changed (Tenn. Code 36-5-101(g)(1)). Unless a significant variance exists, an order is not eligible for modification (1240-02-04-.05(2)).
What is the percentage?
For orders set under income shares, at least a 15% change between the current order, not counting any deviation, and the proposed presumptive support order; or at least 7.5% if the parent seeking modification is a low-income provider, meaning a parent who is not willfully and voluntarily unemployed or underemployed and whose adjusted gross income is at or below the federal poverty level for a single adult (1240-02-04-.05(2)(c)-(d)). The Tennessee child support modification calculator applies both lines.
| Existing monthly order | 15% up | 15% down | 7.5% up | 7.5% down |
|---|---|---|---|---|
| $200 | $230 | $170 | $215 | $185 |
| $500 | $575 | $425 | $538 | $462 |
| $800 | $920 | $680 | $860 | $740 |
| $1,500 | $1,725 | $1,275 | $1,612 | $1,388 |
With an $800 order, $1,000 is 25% higher and passes the 15% line; $900 does not.
Does the court have to follow the guidelines?
The guideline amount is a rebuttable presumption. To depart, the court must make a written finding that applying the guidelines would be unjust or inappropriate to provide for the child’s best interest or equity between the parties, stating the amount the guidelines would have produced and a justification for the variance (36-5-101(e)).
What if my Tennessee order has a deviation?
The court does not count a previous deviation in the comparison. If the variance exists only because of a prior deviation whose reasons have not changed, the order is not modified; if other circumstances, such as a change in income, would create a significant variance once the deviation is set aside, the order may be modified (1240-02-04-.05(3), (5)).
Do health care needs count in Tennessee?
Yes. The necessity of providing for the child’s health care needs is a basis for modification regardless of whether a modification of the amount is warranted by other criteria (36-5-101(g)(2); 1240-02-04-.05(2)(a)).
What about a new child in Tennessee?
The birth or adoption of another child the obligor is legally responsible for and supports is a substantial and material change for seeking a review; the court then checks whether the new child and any credits give a significant variance (36-5-101(g)(4)). A parenting time adjustment, a change in the number of children and work-related child care count only if the significant variance requirement is met (1240-02-04-.05(6)).
From what date can the order change?
No ordered child support is modifiable for any time period or amounts due before an action for modification is filed and notice has been mailed to the last known address of the opposing parties (36-5-101(f)(1); 1240-02-04-.05(8)). Every month before filing is lost:
| Monthly difference | Lost after 6 months | Lost after 12 months |
|---|---|---|
| $100 a month | $600 | $1,200 |
| $200 a month | $1,200 | $2,400 |
| $400 a month | $2,400 | $4,800 |
Federal law also bars retroactive modification of support already due (42 U.S.C. 666(a)(9)).
What happens next?
Read how to modify child support in Tennessee for the filing steps, and check what stays owed with the Tennessee arrears calculator.
Frequently asked questions
What is a significant variance in Tennessee child support?
At least a 15% change between the current order and the proposed presumptive order, or 7.5% for a low-income provider.
Does a Tennessee deviation count toward the 15%?
No. The comparison leaves out any deviation amount.
Can a new child modify Tennessee child support?
The birth or adoption of another child you support is a ground to seek a review for a significant variance.
Can health care needs modify Tennessee child support without a 15% change?
Yes. They are a basis for modification regardless.
Can Tennessee modify support that came due before I filed?
No. Not for any period before filing and mailing of notice.
Official sources
- Tenn. Code 36-5-101: decree for support; modification; enforcement
- Tenn. Comp. R. & Regs. 1240-02-04: child support guidelines (version revised 2008)
- 42 U.S.C. 666(a)(9): no retroactive modification of support already due
- 45 CFR 302.56: federal guideline requirements
A local family law attorney can review your situation — many offer a free consultation.
This is general information, not legal advice. It is based on the cited Tennessee statutes, rules and court opinions, and every case turns on its own facts. Confirm how the law applies to your situation with a licensed Tennessee attorney.