Can I return to my H1B status if I switch to TN to start new job immediately?

It sounds like a lot of work – getting a TN – and then changing that over to H-1B (when you can immediately start to work for your new employer once the H-1B transfer papers are filed with U.S.C.I.S.). That latter process may take approximately 3-4 weeks, but the convoluted process that you are contemplating may only save one or two weeks as you and the company will still have to put together an effective TN application, and afterwards have to go through the trouble of an H-1B/ change of status petition anyway. Due to the limitations of the Lawyers.com Forums, Alan Lee, Esq.'s (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.