US CITIZENSHIP
US citizenship may be acquired by birth, descent, naturalisation or, in limited circumstances, adoption. For most immigrants, the route is naturalisation after obtaining lawful permanent resident status, commonly known as a Green Card.
Immigration to the United States through family, employment, investment, asylum or the Diversity Visa programme can lead to permanent residence, but a Green Card does not convert into citizenship automatically. Naturalisation requires a separate application to USCIS.
AT A GLANCE
- Most Green Card holders may apply for naturalisation after five years of continuous residence.
- A qualifying spouse of a US citizen may use the three-year rule if all family and residence conditions are met.
- Applicants normally need physical presence in the United States, good moral character, English ability and civics knowledge.
- The United States permits multiple citizenship, although the applicant must take the Oath of Allegiance.
CONTENTS
Who can apply for US citizenship
Ordinary naturalisation is available to a lawful permanent resident who is at least 18 years old and meets the requirements set by US Citizenship and Immigration Services. The applicant must keep permanent resident status until the oath ceremony and must be able to show that the United States has remained their genuine place of residence.
In the usual case, an applicant needs to:
- be at least 18 years old;
- hold lawful permanent resident status;
- complete the applicable period of continuous residence;
- meet the physical-presence requirement;
- show good moral character;
- pass the English and civics tests unless an exception applies;
- take the Oath of Allegiance.
IMPORTANT
A Green Card is not US citizenship. Even after the qualifying residence period has passed, the applicant must file Form N-400 and satisfy USCIS that every requirement is met when the case is decided.
Five-year and three-year naturalisation rules
The standard rule requires five years of continuous residence as a lawful permanent resident. In many cases, Form N-400 may be filed up to 90 calendar days before the fifth anniversary, provided that all other requirements are already met.
The three-year route is available only to a permanent resident who has been married to, and living in marital union with, the same US citizen spouse for the required period. Marriage alone does not grant citizenship and does not remove the other naturalisation conditions.
Typical naturalisation timelines
| Applicant category | Continuous residence | Physical presence |
|---|---|---|
| Most lawful permanent residents | 5 years | 30 months |
| Qualifying spouse of a US citizen | 3 years | 18 months |
| Some members of the US armed forces | Special rules | Depends on service |
Work in the USA can provide the first practical route to a long-term immigration status, but overseas assignments and extended time abroad should be reviewed carefully. Employment does not preserve continuous residence by itself.
Continuous residence and physical presence
Continuous residence and physical presence are separate tests. Continuous residence concerns whether the United States remains the applicant’s settled home. Physical presence counts the actual days spent in the country during the relevant three- or five-year period.
A trip abroad lasting more than six months can create a presumption that continuous residence was interrupted. An absence of one year or more will normally break the period unless a specific statutory protection applies. Frequent travel can also leave an applicant short of the required 30 or 18 months of physical presence.
Applicants should keep a complete travel history before filing. Passport stamps, airline records, tax returns, lease agreements, employment records and bank statements can help establish where a person actually lived.
English, civics and good moral character
The naturalisation interview usually includes basic English speaking, reading and writing. The civics test covers US history, constitutional principles, government institutions and citizens’ rights. Some older permanent residents with a long residence history, as well as certain applicants with disabilities, may qualify for modified rules or exemptions.
Good moral character is assessed mainly during the statutory period, although USCIS can consider earlier conduct where relevant. Criminal convictions, false statements in immigration filings, unpaid tax obligations, failure to support dependants and other serious issues can lead to denial or delay.
The law does not impose a single salary threshold for citizenship. The latest salary in the United States data report median usual weekly earnings of $1,251 for full-time workers in the second quarter of 2026. That labour-market figure is not a naturalisation requirement; tax compliance and truthful financial information are more important to the application.
Documents and the N-400 process
The process normally begins with Form N-400. USCIS may then collect biometrics, request evidence, schedule an interview, administer the tests and issue a decision. Citizenship is completed only at the oath ceremony.
A typical application may require:
- a copy of the Green Card;
- passports and a full travel history;
- address and employment history;
- marriage, divorce and child-related documents where applicable;
- tax records;
- court or police documents where an arrest, charge or conviction occurred;
- evidence supporting any claimed test exemption or accommodation.
USCIS can ask for further evidence where dates, names, travel records or previous immigration applications do not match. It is better to disclose relevant past events with supporting documents than to omit them.
Family, military and citizenship by descent
Marriage to a US citizen can support a family-based Green Card and, later, the three-year naturalisation route. USCIS examines whether the marriage is genuine and whether the couple has maintained the required marital union.
A child may be a US citizen at birth because they were born in the United States or because a parent was a US citizen who met the statutory residence conditions before the child’s birth. The applicable rule depends on the child’s date of birth, the parents’ citizenship and their residence history.
Military service can offer a separate and sometimes accelerated route to naturalisation. Eligibility depends on the character and period of service, so applicants should use the military-specific USCIS rules rather than assume the ordinary five-year timeline applies.
Dual citizenship and life after naturalisation
The United States permits dual and multiple citizenship. However, naturalised citizens take an Oath of Allegiance to the United States. The law of the other country may still impose its own rules on retaining or giving up another nationality.
Naturalised citizens may vote in federal elections, hold a US passport, live and work in the country without an immigration time limit and pass citizenship to children where statutory conditions are met. A passport is applied for after citizenship is acquired; it is proof of the status, not the source of it.
Living in the United States differs sharply by state and city. Income, rent, health insurance, taxes and transport costs affect a household’s real budget, so a country comparison is most useful before relocation when it considers both earnings and long-term immigration prospects.
Sources
- US Citizenship and Immigration Services — USCIS.
- Immigration and Nationality Act.
- US Department of State.
- US Department of Homeland Security.
- Bureau of Labor Statistics.
Frequently Asked Questions
When can I apply for US citizenship after receiving a Green Card?
Most lawful permanent residents may apply after five years of continuous residence. A qualifying spouse of a US citizen may use the three-year rule if every relevant condition is met.
Can travel outside the United States affect naturalisation?
Yes. An absence of more than six months can affect continuous residence, and an absence of one year or more will normally interrupt it unless a special rule applies. Travel also affects the physical-presence calculation.
Do I need to pass an English test?
Usually, yes. USCIS tests basic English and civics knowledge, although some older permanent residents and applicants with qualifying disabilities may use modified rules or exemptions.
Can I keep another citizenship after becoming a US citizen?
US law permits multiple citizenship. The applicant should also check the law of their other country, which may have different rules.
Does marriage to a US citizen grant citizenship automatically?
No. Marriage can create a route to permanent residence and later to the three-year naturalisation rule, but it does not remove the need to meet the other USCIS requirements.
Founder and Editor-in-Chief of WageCentre, with a degree in finance and 15+ years of professional experience. He writes about salaries, taxes, labour markets, immigration and financial planning for relocation.
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