Here is what I found regarding that... "Corporations You will be required to obtain a new EIN if any of the following statements are true. A corporation receives a new charter from the secretary of state. You are a subsidiary of a corporation using the parent's EIN or you become a subsidiary of a corporation. You change to a partnership or a sole proprietorship. A new corporation is created after a statutory merger.
You will not be required to obtain a new EIN if any of the following statements are true. You are a division of a corporation. The surviving corporation uses the existing EIN after a corporate merger. A corporation declares bankruptcy. The corporate name or location changes. A corporation chooses to be taxed as an S corporation. Reorganization of a corporation changes only the identity or place. Conversion at the state level with business structure remaining unchanged." https://www.irs.gov/businesses/small-businesses-self-employed/do-you-need-a-new-ein