Category with subcategories setting?

mjrudi said:

I dont want a transaction to be assigned to any category that has a subcategory. I just find it odd to do. Is there a setting that if turned on prevents using a category with subcategories?

So you have a Category = Medical with subcategories of "Doctor", "Hospital", "Prescriptions".  You choose to NOT assign the upper level Medical category to any transaction.  Very reasonable, IMO. 

There is no way I know of to have Quicken lock out that upper level category. 

NotACPA's suggestion to have (perhaps) three categories of Med-Doctor, Med-Hospital, and Med-Prescription would basically accomplish you goal at an expense of not seeing those three added together.  No Total Medical in many reports.  I would not make that choice 

You might want to vote for this idea:
https://community.quicken.com/discussion/7873849/add-ability-to-lock-categories