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US Naturalization Requirements & Applications

By Nita Nicole Upadhye

Table of Contents

US naturalization requirements & application guidance

Becoming a US citizen is a significant legal step. Once you have naturalized as a US citizen, you will be able to apply for a US passport. You will be permitted to travel free from US immigration controls, and you will also gain the right to vote in the US.

There are a number of routes for foreign nationals to attain US citizenship, depending on circumstances and eligibility These include US citizenship through marriage, US citizenship through birth, US citizenship through military service and most commonly, US citizenship through naturalization.

If you are applying to naturalize as a US citizen, you should be aware that the eligibility requirements are strict, and the application process is complex, typically taking over a year to conclude.

In this guide to US naturalization, we explain the eligibility criteria you will need to be eligible to become a US citizen through naturalization and the process you’ll need to follow to make your application.


What is US naturalization?

The legal process of being granted US citizenship is known as naturalization. It applies to individuals who do not automatically hold US citizenship, either by birth or who did not acquire or derive US citizenship from their parent(s).

Under the Immigration and Nationality Act (INA), to apply for US citizenship, an individual must meet specific eligibility criteria and make a formal application to USCIS.

Before embarking on the US naturalization process, it helps to understand what USCIS will be looking for in your application. The naturalization process can take between one and two years to complete, provided all relevant documents have been submitted and you pass the required tests. Errors or omissions in your application could result in a delayed decision or worse, a refused application.


US naturalization requirements

If you do not automatically hold US citizenship, you first need to be certain you are eligible before making – and paying for – an application to naturalize.

The most common route to citizenship is by holding a US Green Card for a minimum of five years.

Exceptions to this time rule do exist. For example, Green Card holders married to US citizens require a lesser minimum of three years of US permanent residence in order to naturalize. Green Card holders in the military and their dependents also differ in the time period criteria. We can advise on your specific circumstances if you fall under these classifications.

In addition to the five-year continuous residence requirement, the main criteria for US naturalization are:

  • You have had continuous presence in the US for a minimum of 30 months out of the five years immediately preceding your application date
  • You are of good character
  • You meet the English language requirement
  • You have good knowledge of US history and government
  • You are least 18 years old
  • Taking the Oath of Allegiance

Where the applicant has permanent physical or mental impairment preventing them from meeting these requirements, exemptions may be available. Again, take professional advice on the specific circumstances.


Applying for US naturalization

If you meet the eligibility criteria, the next step is to make your US naturalization application.

To do this, you need to complete and file Form N-400, ‘Application for Naturalization’ with USCIS. You will also need to pay the relevant filing fee at the current rate. At the time of writing, the fee for a US naturalization application is $725, which is made up of $640 for processing and $85 for biometrics services, both of which are non-refundable.

Accompanying the form should be a photocopy of both sides of your Permanent Resident card, proof of payment of the fee, and if you reside outside the US, two identical color photographs.

Along with the form, you also will be required to collate and submit supporting documents. The specific documents to include will depend on the basis of your eligibility, for example, if your application is based on your marriage to a US citizen.

Once your application has been received, you will be asked to provide your biometric information at an Application Support Centre.

Security checks will then be carried out ahead of your US naturalization interview.


What happens at the naturalization interview?

You will be interviewed by a USCIS officer. They will ask you a series of questions about your application – about you, your circumstances and the information you have provided in your Form N-400. You will be under oath and required to answer truthfully and comprehensively.

At this stage, you will also sit the English and civic tests, unless you qualify under one of the exemptions, such as medical disability.

To help you prepare for the citizenship tests, USCIS provides educational materials and resources. Studying these in advance will improve your chances of passing.

If, on the day of your interview, you fail part of the civic or English language tests, you will be given an opportunity to retest on the part that you failed. This will be between 60 and 90 days from the date of your initial interview.

Your US natualization application will then progress in one of three ways:

1. Application approved

You passed the interview and civic and language tests, and your application is approved.

To complete your naturalization, you will have to take an Oath of Allegiance at a public ceremony.

Your Certificate of Naturalization will be issued as proof of citizenship at the oath ceremony. It will be important to retain this document for future purposes.


2. Decision delayed

Following your interview, the USCIS officer may require further information before a decision is made on your application.

This could mean a further written request is sent to you for additional information to be provided.

Ensuring correct preparation of your original application can help to avoid this scenario, and any ensuing delay with the decision.


3. Application denied

You will receive formal notification from USCIS if your application is denied, which should also detail the grounds for refusal.

Based on the reasons provided, you may choose to appeal the decision. You have only 30 days from the refusal notice to request an appeal hearing, so it will be important to act quickly. Take advice to assess the merits of your challenge and help build your strategy and response to the decision.


Can children apply for US naturalization?

It is possible for children born outside of the US to a US citizen parent(s) to acquire US citizenship. It requires the US citizen parent(s) to apply to naturalize each child using Form N-600K.

The criteria are:

  • at least one parent is a US citizen, either by birth or by naturalization;
  • the child is and will remain under 18 until the naturalization process is completed;
  • the citizen parent must have lived in the US for a total of five years, at least two of which were after age 14; OR the US citizen parent of the citizen parent (child’s grandparent) must have lived in the United States for a total of five years, two of which were after age 14;
  • the child is not married;
  • the child is residing outside of the US with the citizen parent; and
  • the child is temporarily present in the US under a lawful admission, and remains in lawful status until the naturalization process is completed.


Need help with US naturalization?

If you do want to proceed with US naturalization, you’ll want to avoid any issues with your application, since the stakes are so high. But the naturalization process is complex – ensuring you meet the eligibility criteria, understanding if and where any exemptions apply, and how to put your application together and preparing well for the interview and tests.

NNU Immigration are specialist immigration attorneys helping individuals with all aspects of their US naturalization applications.

If you have a specific question on naturalization, please contact us for advice.


US naturalization FAQs

How long do you have to live in the U.S. to become a naturalized citizen?

In most cases, you will need to have lived in the US for five years with lawful status before you are eligible for naturalization, unless you are married to a US citizen, in which case this is reduced to 3 years.


Is a green card the same as naturalization?

No, a Green Card confers permanent residence but it does not impact citizenship. Naturalization is the legal process by which a lawful permanent resident can apply to become a US citizen.

This article does not constitute direct legal advice and is for informational purposes only.


Founder & Principal Attorney Nita Nicole Upadhye is a recognized leader in the field of US business immigration law (AILA) and trusted adviser to large corporates through to SMEs, providing strategic immigration and global mobility advice to support employers with both US and UK operations to meet their workforce needs through corporate immigration.

Nita successfully acts for corporations and professionals, entrepreneurs, artists, actors, and athletes from across the globe, providing expert guidance on all aspects of US visa and nationality applications, and talent mobility to the USA.

Nita is an active public speaker, thought leader, immigration commentator, and immigration policy contributor and regularly hosts training sessions for employers and HR professionals

Need legal advice?

For specialist advice on your query, get in touch with our team of US immigration attorneys.​

Need legal advice?

For specialist advice on your query, get in touch with our team of US immigration attorneys.

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For specialist advice on a US immigration or nationality matter for your business, contact our US immigration attorneys.

For specialist advice on a US immigration or nationality matter for your business, contact our US immigration attorneys.