Generally arrearages which have already vested cannot be modified upon filing a supplemental petition to modify child support. When one has experienced a substantial change in circumstances which justifies child support to be modified by at least 15% or $50, whichever is more, the Court may modify the child support. However, modification can only occur upon the filing of a supplemental petition. Once child support payments become due the support becomes a vested right and generally cannot be modified retroactively. There are a few exceptions to this rule when compelling circumstances and proper pleadings justify a modification of the arrearages. Primarily, the exception is limited to cases where a party is incarcerated preventing them from filing the modification and the compelling reason is proper plead in the pleadings.
However, even within this narrow exception, the Court may still deny the modification of vested arrearages. For example, in a recent case out of the Fifth District Court of Appeal, the Court found it improper to modify the child support arrearages even when the subject children had already reached adulthood. The Court found that the father should have filed a supplemental petition to modify child support upon his incarceration and not after his release. Further the Court cited numerous cases standing for the principle that child support rights vest at the time the payments are due. “Thus accrued child support, or child support in arrears, become vested rights of the payee and vested obligations of the payor that are not subject to retroactive modifications."Puglia v. Puglia, 600 So. 2d 484, 485 (Fla. 3d DCA 1993).
It is very important that when a substantial change in circumstances has occurred justifying a modification of child support that the supplemental petition for modification be filed immediately. Once the payment has become due, it is highly unlikely the Court will modify the arrearage.
See,Cortina v. Lorie, 37 Fla. L. Weekly D2037 (Fla. 5th DCA 2012).