my 50 year old son gets DAC from his father, when he reaches age 67 for old age benefits will he just automatically be transferred to that status. I receive almost 1500 monthly, he gets over 800 now on his deceased father, so will he get the highest benefit at that age?
No, your son wouldn't automatically be transferred from disabled adult child's (DAC) benefits to regular Social Security retirement benefit at any point in time. He would have to file for those benefits, and he would only qualify for Social Security retirement benefits if he himself has worked enough to earn at least 40 quarters (10 years) of Social Security credits. And, if your son does qualify for Social Security retirement benefits in the future, he could only get the higher of his own retirement benefit rate or his DAC rate.
Your son would probably be eligible for DAC benefits on the higher of your Social Security record or his father's record. Survivor DAC benefits are calculated at a rate of 75% of the deceased parent's primary insurance amount (PIA), whereas DAC benefits on the record of a living parent are calculated based on 50% of the parent's PIA. If 75% of your son's father's PIA is higher than 50% of your PIA, then he's likely getting all of the DAC benefits he could get for now. But, in the event of your death he could switch to 75% of your PIA if that amounts to more than 75% of his father's PIA.