I have a health care business as a sole proprietor, I would like to incorporate it for liability reason. Would I be able to use the same TIN, and NPI numbers when I convert? Or I need new numbers? Thank you.
You'll need a new federal tax ID. California (where we conduct business) converted our sole prop state tax ID to the corporation with the filing of a required form.
Our CPA was absolutley invaluable in guiding us through these types of issues when we incorporated.
You might also benefit from the book I mention in this question on incorporating.