The 23-year-old centre-back initially spent the first half of 2023/24 on loan at Port Vale, making 16 appearances in all competitions.
He will now join Johnnie Jackson’s AFC Wimbledon side as they push for promotion in the top half of League Two.
Balmer is the second Palace Academy player to make the switch to the Cherry Red Records Stadium this month, with John-Kymani Gordon also joining on loan earlier this month.
Everyone at the club wishes Kofi well on his loan spell.