Hello. I am in the process of returning to work after being on LTD. I have opted for a negotiated exit. Can my insurance company claim any of this?

It would depend on your specific LTD policy. If the insurer is still paying benefits, and your policy states they are entitled to offset employment income, then they may be able to do so. I'd suggest reviewing the policy to get more information (if you don't have a copy, you can ask your case manager for it)