A loan deferment provides confirmation that you were officially registered in a degree program at Harvard Kennedy School. You may have deferred your federal loans while you were enrolled at HKS on, at least, a half-time basis as well as other federal loans for your undergraduate or other graduate school programs.
The Office of the Registrar uploads enrollment details to the National Student Loan Clearinghouse database three times each semester. Loan deferments must have been signed by you when you were an enrolled student and submitted to the registrar. The registrar sends deferments to the appropriate authorizing agencies, to be deemed official.
Email the Office of the Registrar if you have questions specific to a loan deferment you submitted while you were enrolled in a degree program at HKS.