I'm working on an application using .net entity framework. The application keeps track of client information for clients enrolled in programs provided by the organization. Currently I want to alter the database to be able to track family members of the clients as well. Family members will have a lot of the same attributes as regular clients but will not have all of them. Also, a clients family member might be a client themselves.

There's two ways I've thought this could be handled. The first would be that the family members reside in there own table and there is a bridge table between clients and family members. However, if one of the family members becomes a client or vise versa people would need to be moved from one table to the other which doesn't seem preferable.

The other way I thought to do this was just to put them all in the clients table and add a family id for grouping and a flag to say whether they are a client or just a family member of a client. I like this option better, but many of the fields that are not required for family members would be left null (which doesn't seem horrible to me).

Anyone have any thoughts or a better way to organize this?