Can a prenuptial agreement expire?

That is up to you. How long the prenuptial agreement lasts can be defined in the terms of the agreement. For some people, the preference is for the prenuptial agreement to stand indefinitely. For others, a “sunset” clause can specify when a prenuptial agreement should expire or how it may phase out over time. For example, terms may change as your marriage hits the 10-year mark, the 15-year mark and the 20-year mark.