Lawful permanent residents may naturalize to become U.S. citizens to obtain all the benefits of citizenship. Most permanent residents may file an application for naturalization after 5 years, and spouses of U.S. citizens may do so after 3 years, provided that the applicant has been physically present in the United States for at least 50% of such time. The application process requires an interview with an immigration officer, an English language exam, and a U.S. civics exam. Certain individuals may be exempt from English and/or civics exam on the basis of age, physical or mental impairment, and the amount of time they have lived in the United States. If successful, the naturalization process concludes with a swearing-in ceremony where the applicant takes the oath of citizenship.