Students who meet the GPA requirement (4.5) are invited to apply in the fall (late September) of their junior year (or senior year if they are not already a member). There is an informational meeting (usually in early October) to inform students about the pillars of NHS (scholarship, character, service, leadership) that they are supposed to demonstrate they possess through the prospective member form (application). The way they demonstrate these traits on the application is mostly through a listing (and getting sponsors to sign off to verify) of co-curricular and extra-curricular involvement, service in organizations or independently in the community, leadership (both formal/elected and informal) experience, and awards.
Students have about a month to complete the application (generally due in early November) because they are asked not only to fill out information but also to complete 10 service hours in the month. A faculty committee selected by the principal reviews the prospective member forms and decides who will be invited to be new members. This list usually comes out in late November or early December. These students are inducted usually in February of the following semester.