Will this qualify for modification of CS?

My ex’s daughter will turn 18 in November and he will no longer be paying child support to her…nor will he get to “claim” her as a deduction (or credit) for his child support calculation.

I did the CS calculator and this change shows a 75% increase in his CS payment (and isn’t 15% the guideline)? This is a substantial change, but I wasn’t sure if you also had to WAIT 3 yrs before you can modify REGARDLESS of the 15% guideline change??

Please clarify Erin if this could be a reasonable request to modify CS.

Thanks!

The guidelines that that three years time must pass for a modification based on a 15% change.