A national provider identifier (NPI) is a unique ten-digit identification number required by HIPAA for all health care providers in the United States.
Generally, the law in New Hampshire is that child support ends when the child turns 18 or graduates from high school, whichever is later. Yet, the answer to the question is not that simple. Sometimes, there may be a circumstance which can extend child support, for example if your child is disabled.
As a general matter, the obligation of a parent to support a child terminates when the child attains the age of majority, which in Connecticut is 18 (CGS  1-1d; Kennedy v. Kennedy, 177 Conn. 47, 52, (1979); Sillman v. Sillman, 168 Conn. 144 (1975)).