Chapter 1 - Purpose and Background
All applicants who meet the eligibility requirements to derive or acquire citizenship or to become naturalized  United States citizens are eligible to receive a certificate from USCIS documenting their U.S. citizenship.  The burden of proof is on the applicant to establish that he or she has met all of the pertinent eligibility requirements for issuance of a certificate.
The Certificate of Citizenship is an official record that the applicant has acquired citizenship at the time of birth or derived citizenship after birth. 
The Certificate of Naturalization is the official record that the applicant is a naturalized U.S. citizen. 
USCIS strictly guards the physical security of the certificates to minimize the unlawful distribution and fraudulent use of certificates.
In general, in order to obtain either a Certificate of Citizenship or a Certificate of Naturalization from USCIS, a person must:
File the appropriate form and supporting evidence;
Appear for an interview before an officer, if required;
Meet the pertinent eligibility requirements, as evidenced by USCIS approval of the form; and
Take the Oath of Allegiance, if required.
USCIS District Directors, Field Office Directors, and other USCIS officers acting on their behalf, have delegated authority to administer the Oath of Allegiance in USCIS administrative oath ceremonies and to issue certificates. 
[^ 1] The Immigration and Nationality Act (INA) defines naturalization as the “conferring of nationality of a state upon a person after birth, by any means whatsoever.” See INA 101(a)(23). Accordingly, any person who obtains citizenship after birth, even if that citizenship is obtained by automatic operation of law, such as under INA 320, is a “naturalized” citizen under the law. For ease of reference, this volume uses the term naturalized citizen to refer to those persons who do not acquire automatically but instead file an Application for Naturalization (Form N-400) and proceed through the naturalization process in their own right.
[^ 2] A person who automatically acquires citizenship may also apply for a U.S. Passport with the Department of State to serve as evidence of his or her U.S. citizenship.
[^ 4] See the relevant Volume 12 [12 USCIS-PM] part for the specific eligibility requirements pertaining to the particular naturalization provision, to include Part D, General Naturalization Requirements [12 USCIS-PM D]; Part G, Spouses of U.S. Citizens [12 USCIS-PM G]; and Part I, Military Members and their Families [12 USCIS-PM I].
INA 310(b)(4) - Naturalization authority and issuance of certificates
Before October 29, 2019, USCIS considered children of members of the U.S. armed forces or U.S. government employees, who were stationed outside of the United States, to meet the requirement of “is residing in” the United States for the purpose of acquiring citizenship under INA 320. This interpretation was consistent with the definition of “residence” for purposes of naturalization under INA 316. Based on this treatment of U.S. government employees and their children in the context of naturalization under INA 316, USCIS determined that “residing in the United States” for purposes of acquisition of citizenship under INA 320 should likewise be interpreted to include children of U.S. military and government employees stationed outside of the United States who were residing with their parents.
This interpretation, however, was inconsistent with other provisions of the Immigration and Nationality Act (INA), including the definition of “residence” at INA 101(a)(33) and language in INA 322(a) and INA 322(d), which suggested that the citizenship of military children residing outside of the United States should be considered under that provision rather than under INA 320. Effective October 29, 2019, USCIS amended its policy guidance to address these concerns, and determined that children of members of the U.S. armed forces or U.S. government employees stationed outside of the United States would not be eligible for citizenship acquisition under INA 320.
On March 26, 2020, the Citizenship for Children of Military Members and Civil Servants Act was enacted, amending INA 320, so that a child residing with his or her U.S. citizen parent, who is stationed outside of the United States as a member of the U.S. armed forces or a U.S. government employee, or is residing in marital union with a member of the U.S. armed forces or a U.S. government employee who is stationed outside of the United States, acquires citizenship under INA 320 if all requirements of INA 320(c) and INA 320(a)(1)-(2) are met. In line with the statute, USCIS rescinds its previous guidance, clarifying that these children are eligible to acquire citizenship under INA 320 if all other requirements under INA 320 are met.
The amendment to INA 320 applies to children who were under the age of 18 on March 26, 2020.
[^ 1] Even though the child of a member of the U.S. armed forces or U.S. government employee stationed outside of the United States may be eligible to apply for a Certificate of Citizenship under INA 322 since he or she resides outside of the United States, USCIS interpreted the child to meet residency requirements under INA 320 as well, which formerly required the child to be residing in the United States with his or her parent to acquire citizenship.
[^ 2] For example, U.S. government employees, including members of the U.S. armed forces, are eligible to apply for an exception to the continuous residence requirement for naturalization under INA 316 as long as their residency outside of the United States was on behalf of the U.S. government. See INA 316(b). See INA 316(a). See Part D, General Naturalization Requirements, Chapter 3, Continuous Residence [12 USCIS-PM D.3].
[^ 3] See Policy Manual Technical Update, Child Citizenship Act and Children of U.S. Government Employees Residing Abroad (July 20, 2015); and Acquisition of Citizenship by Children of U.S. Military and Government Employees Stationed Abroad under Section 320 of the Immigration and Nationality Act (INA), No. 103, issued May 6, 2004.
[^ 4] See USCIS Policy Alert, Defining “Residence” in Statutory Provisions Related to Citizenship [PA-2019-05] (PDF, 308.45 KB). This Policy Alert has been superseded by Policy Manual updates to reflect changes made under Pub. L. 116-133 (PDF).
U.S. Citizenship and Immigration Services (USCIS) is updating and incorporating relevant Adjudicator’s Field Manual (AFM) content into the USCIS Policy Manual. As that process is ongoing, USCIS has moved any remaining AFM content to its corresponding USCIS Policy Manual Part, in PDF format, until relevant AFM content has been properly incorporated into the USCIS Policy Manual. To the extent that a provision in the USCIS Policy Manual conflicts with remaining AFM content or Policy Memoranda, the updated information in the USCIS Policy Manual prevails. To find remaining AFM content, see the crosswalk (PDF) between the AFM and the Policy Manual.
This technical update replaces all instances of the term “foreign national” with “alien” throughout the Policy Manual as used to refer to a person who meets the definition provided in INA 101(a)(3) [“any person not a citizen or national of the United States”].
USCIS is issuing updated and comprehensive citizenship and naturalization policy guidance in the new USCIS Policy Manual.