Again, you and they have to follow the terms outlined in the contract. if the contract states 90 days notice, usually it is on both sides (they give you 90 days and you give them 90 days)
Without a contract in place you run the risk of working for nothing since there is nothing stopping them from not paying you.
If you do not have a contract, I strongly suggest sitting down with the provider and coming up with one for purpose of transitioning them from your services.. IF you plan on continuing to submitting claims.
In your post you said you were in process of having contract drawn up so I'm guessing you don't have one? If not I don't think anyone here can help you in deciding how to terminate and on what terms since it's after the fact. I would consult an attorney OR just hope the practice will specify terms in ending the relationship.
Linda Walker
PMRNC
www.billerswebsite.com