I manage, and partially-own, two family S corps with 53% overlapping ownership.  The larger S corp is clearly in the real estate rental business with 30 tenants.  The other just has cash but plans to buy a rental property. 

Would the single-tenant S corp qualify as a business for purposes of the qualified business income deduction of section 199A?  What if it buys a NNN property, then would my involvement in the real estate business combined with the overlapping ownership put the single-tenant S corp in the real estate rental business too?  This is like driving in a blinding snowstorm.  Tax law sucks!