The laws of New Hampshire state that identifying information must be shared with an adult adoptee (age 21) if the birth parent(s) has/have signed a release form. Information will not be released unless such a form is on file with the agency and the agency has attempted to contact the birth parent(s) to reaffirm the desire to be contacted. Non-identifying information is available to adult adoptees and adoptive parents. 
N.H. Rev. Stat. Ann 170-B:19.