The lower court erred in determining that the marital settlement agreement provided for automatic modification of child support upon each child attaining majority or emancipation and in making the child support modification retroactive. Department of Revenue v. Hall, 699 So.2d 1036 (Fla. 5th DCA 1997); Livingston v. Livingston, 686 So.2d 664 (Fla. 1st DCA 1996). Therefore, we reverse those portions of the modification order terminating support retroactive to the children’s 18th birthday or date of graduation from high school and setting the arrearage amount. On remand, the court must recalculate, the arrearage amount to include the vested but unpaid child support and should make specific findings to support its determination.

AFFIRMED in part, REVERSED in part, and REMANDED for further proceedings.