N.H. Cir. Ct. Fam. Div. R. 5.7

Any person, including the minor if fourteen (14) years of age or older, may petition the court to terminate a guardianship. The court will determine by a preponderance of the evidence whether substitution or supplementation of parental care and supervision is no longer needed to ensure the minor’s safety and physical and psychological well-being.

In addition to terminating a guardianship by Court order, guardianships terminate upon the death of the minor or upon the minor’s eighteenth (18th) birthday. The guardian must notify the court within thirty (30) days of either event. Guardianships may also terminate upon the minor’s adoption or emancipation. However, if the minor consents, jurisdiction may be extended beyond the eighteenth (18th) birthday if DHHS is the guardian and supports continued jurisdiction, and the minor is attending high school and considered likely to complete it. If extended, jurisdiction shall terminate if the minor revokes consent and such revocation is approved by the Court, completes high school or attains age twenty-one (21), whichever first occurs, or if DHHS revokes its consent and such revocation is approved by the Court. See RSA 463:15.