If you have already done this, you need to see a tax accountant. If you have not done it yet, you need to see an attorney who specializes in estate planning (and who probably has financial training or has accountants on staff.) You need to tell the attorney what you want to accomplish (avoid probate, protect assets from Medicare or other government grabs, etc.) and let the attorney tell you the best way to accomplish your goal.
I will add, since @Carl did not, that gifting the rental property to your son also gifts him with your depreciated cost basis, and he will probably owe significant capital gains tax if and when he sells, that could maybe be avoided if you used other methods to transfer ownership to him. Gifting him the property will also significantly reduce his own deductions for depreciation.
