N.H. Rev. Stat. Ann. § 294-A:30

This chapter shall apply to all existing associations or corporations organized under the law of this state which is superseded by this chapter. Every such existing professional association or corporation which shall be required to amend its corporate name or purposes to comply with this chapter shall deliver duly executed duplicate originals of articles of amendment or restated articles of incorporation containing the amendments to the secretary of state within 90 days after the effective date of this chapter.