This is ONLY TRUE if you reside with both divorced parents an equal number of days…50/50%. If that is the case…then you would be required to use the parent who provided the greater amount of support.
BUT…you have stated repeatedly here that you live with your mom a higher %age if the time than you live with your dad. Is that correct?
If so…your mom is the ONLY parent listed on the FAFSA. Period.
Read the post from @BelknapPoint that quotes the directions from the FAFSA.
Then remember…there is NO simplified needs test or auto $0 EFC for schools requiring the Profile.
Also…how many times do you need an explanation of which parent to use on the FAFSA? It’s clear on this thread as well.