I always have to make sure that the folks have their FAA medicals
There are different views on this. Most people think that FAA piggyback licenses don't need the FAA medical. Some think that the FAA medical is required only if you also have the FAA IR.
The FAA FAQ (latest version is c. 2004; not on their website any more but I have a copy) doesn't deal with this old question.
Any supporting references for the above?