Ex-USCIS officer reveals 2 biggest mistakes that derail N-400 US citizenship applications

In an exclusive conversation with Financial Express Digital, former supervisory Immigration Services officer Douglas S Pierce, who retired from US Citizenship and Immigration Services (USCIS) in October 2025 after over 33 years of service, said many applicants fail because of timing and eligibility mistakes they do not notice while filing form N-400. He personally interviewed more than 10,000 applicants and oversaw tens of thousands of naturalisation interviews during his career with the Immigration and Naturalization Service (INS) and USCIS.

What are the most common eligibility mistakes in N-400 filings?

Pierce said two mistakes appear more often than others in naturalization cases. “The two most common eligibility mistakes that people make when filing for naturalisation are, firstly, filing too soon after they have just completed a move from one jurisdiction to another,” he said.

“Secondly, people who are married to United States citizens who file either too early. The exception that allows some people to file up to 90 days before they are otherwise eligible doesn’t apply to all of the potential eligibility factors,” he said. He said applicants often misunderstand residency rules and timing requirements, which differ depending on the basis of eligibility.

What happens inside interview room when an applicant is found ineligible?

Pierce described a structured but difficult process when eligibility issues surface during an interview. “Usually the officer will have brought the applicant into the office, closed the door, and after placing them under oath, they will verify the information that potentially makes the person ineligible,” he said.

Once the officer confirms the issue, the tone of the interview changes. “Once the information is verified, they will usually look up from their computers and address the applicant, ‘I’m sorry, it does not appear that you are eligible for naturalisation on this application, and this is why…’” Pierce said.

He said officers explain the reason clearly and inform the applicant when they may refile. Applicants may either withdraw the application or proceed to a written decision. “If the person doesn’t wish to withdraw, they are informed that they will receive a written decision in the mail and are dismissed from the office,” he said.

How do applicants usually react when their case ends at the interview?

Reactions vary depending on whether applicants already suspected a problem. “Sometimes, they already know that there is an issue, and usually those folks will accept it and take the information they need to know in order to file again,” Pierce said.

However, others react with surprise and frustration. “When it catches someone off guard, they usually are surprised and sometimes indignant,” he said.

Applicants often question why they were called for an interview at all. “Unfortunately, we are required to schedule an interview so that an officer can go over the information, can verify that it is true and correct, and speak to you in person about the matter,” he said.

Do applicants or lawyers make more of these mistakes?

Pierce said most errors come from applicants who file without professional assistance. “These errors are most often made by individuals who are going through the process without lawyers or accredited representatives,” he said.

He added that repeated mistakes by legal representatives can trigger professional consequences. “If USCIS sees that a lawyer or representative is repeatedly filing cases that are not eligible, those lawyers will be reported for their lack of professional conduct,” he said.

Pierce said many eligibility issues can be prevented with careful reading of instructions, but immigration law remains complex. “Most errors can be avoided if people read through and understand the directions, but immigration law is pretty complex and there are lots of little exceptions and nuances that can be easy to miss,” he said.

Can filing before turning 18 really lead to rejection?

Pierce said such cases are rare but do occur. “I have only seen a couple of cases where someone filed an N-400 before they were 18,” he said.

In most cases, applicants were already US citizens and should have used a different form. “Most of the time, the person was already a citizen through their parents and should have filed the Form N-600 instead,” he said.

He added that some applicants misunderstood legal adulthood rules. “I have seen one or two instances of people who were emancipated from their parents either by court action or because they got married really young,” he said. “Unfortunately, the law doesn’t allow for that,” he added. 

Does 90-day jurisdiction rule still matter?

Pierce said the rule has lost much of its relevance over time. “It is not nearly as relevant as it was before 1997,” he said.

Earlier, applicants often tried to shift jurisdictions to reduce waiting times. “Back then the discrepancies between the waiting times for people living in different districts was significant enough that there was an incentive to find ways to get their cases moved,” he said.

What happens if a divorce occurs during a pending N-400?

Pierce said divorce can significantly affect eligibility, especially in marriage-based cases. “If their N-400 was filed on the basis of being married to a United States citizen, and they did not have five full years as a lawful permanent resident when they filed, then yes, there is likely no way to save that application,” he said.

He added that divorce itself can signal ineligibility in such cases. “Even filing for divorce during the pendency of the application shows a breakdown in the marital relationship,” he said.

Can military applicants lose eligibility after discharge?

Pierce said military-based naturalisation depends heavily on discharge status. “If they get discharged under any category other than honorable, they will lose their eligibility under that special law,” he said.

However, alternative pathways may still exist. “If they are lawful permanent residents and have the required five years of time as a resident and meet the other eligibility requirements like good moral character, they could be eligible under the normal sections of law,” he said.

What Pierce said about N-400 process’ ‘fairness’

Pierce said the naturalisation system is fundamentally fair and structured. “I think the naturalisation process as it is spelled out in law and regulations is very fair and balanced,” he said.

He said citizenship reflects core American values. “It is one of the foundational strengths of the United States that people of any race, ethnicity, religion, and economic background can come to the US, show that they are qualified to join this nation, and become full participating citizens,” he said.

How has enforcement changed in recent years?

Pierce said enforcement priorities have become more strict. “The enforcement priorities of the current administration are unnecessarily harsh, and they appear to be driven by racism and xenophobia,” he said.

He said there is no political framing based on race or religion. “The diversity of our people and culture is a strength, not a flaw,” he said.

Pierce says applicants should be fully transparent in their applications. “Be truthful and honest in all of your answers,” he said.

“If you have a criminal record, get all of the documents from the court and the police,” he said. “Make sure you pay your fines and complete all of the requirements placed upon you, then own up to those errors,” he added. 

Pierce recalled a case involving a man who mistakenly believed he had derived citizenship as a child. His stepfather applied for a US passport on his behalf, which was issued in error. Years later, the mistake resurfaced.

“Nearly 15 years later, the State Department discovered their error and cancelled his passport while he was traveling overseas,” he said. The case escalated into removal proceedings and long-term legal complications. “He is still dealing with this issue 25 years later,” he said.