The Thesis Extension Form is available from your thesis dashboard, top right:

Keep your extension(s) updated with your education technician. This saves you the trouble of reactivating your NPS account when it is time to submit your thesis.

Extension students are expected to adhere to the same submission deadlines as resident students.

The effects of an extension on one's record varies. Military students should see their military service reps for details. Civilian students should speak with their ed techs.

See also Thesis Processing's The Fine Print.

See also the Academic Policy Manual.