Nurse Practitioner Credentialing

Let me also add this in: My current employer says I take my credentialing wherever I go and that's why I would need to pay it back. However, the part time job I'm taking has told me that they still have to get me credentialed with them (she also told me it was only $400). I wish they'd tell us more about this in NP school. Knowledge is power and I feel like I am good target to be taken advantage of simply because I do not know. 

Most places do their own credentialing if they need it and will not accept another facilities credentialing for liability purposes. Your current employer is gas-lighting you to keep you there and buy time to find a replacement for you.

No contract=no obligations beyond professional courtesy. 

I worked on the business side.  Credentialing is time consuming, not necessarily expensive.  I am not saying you need to argue or even seek him out on the conversation.  Professionally I would ignore the comment and do my job to the best of my ability.  However, if he approaches you again you need to figure out how you will calmly, professionally but with a great amount of confidence, state that you know what he has said is not true.  I would, personally, add that in the future he may want to think about contracts if that is his concern but since one does not exist for you, you have nothing but professional courtesy to work with and in light of his statements that is running out quickly.  Figure out how to use this situation to stand up for yourself in a professional manner....guaranteed it won't be the last time you'll need to and the practice won't hurt you.