Al Pacino is a new dad once again at 83, and it ain't gonna be cheap ... he'll pay $30,000 a month in child support, an amount that could grow based on his annual earnings.
According to legal docs, obtained by TMZ, Al and his most recent girlfriend Noor Alfallah -- with whom he welcomed a son named Roman back in June -- just hammered out their custody agreement.
They'll share legal custody of Roman, Noor will get primary physical custody and Al will get visitation.
Both parents will work together when it comes to determining holidays and both have an equal say in schooling decisions and in attending extracurricular activities.
As for child support ... Al is going to pay $110,000 up front and is now responsible for paying $30,000 a month in base child support. He will also have to put $15,000 per year in an education fund and could pay up to an extra $90,000 at the end of the year ... depending on his earnings.
We should note ... he was also paying $13,000 a month for a night nurse, and he's on the hook for any medical expenses outside insurance.