George Lopez to Ex-Wife -- Go Ahead, Take My Retirement Money

George Lopez is still hashing out divorce settlement details with his ex-wife -- over a year after a judge finalized the split -- in fact, the ex-couple JUST decided how to divvy up George's giant retirement stash.

According to new court docs, filed this week in L.A., George and his ex Ann Serrano agreed to split the actor's AFTRA retirement fund down the middle ... but only the portion of the fund representing the contributions George made during their 17-year marriage (from 1993-2010).

It's unclear how much the fund is worth right now -- but Serrano will only get her hands on the percentage from the 17-year period ... even if George continues to deposit money into the account in the future.