Neighborhood Investigations Are Back for N-400 Applicants: What USCIS Checks and How Character Letters Help

What are neighborhood investigations?

A neighborhood investigation is a USCIS inquiry in which an investigator interviews people who know a naturalization applicant to check what the application says and to assess the applicant’s conduct, residence, reputation and community ties. The USCIS Policy Manual, Vol. 12, Part B, Chapter 2 now describes them in detail. The legal authority, INA 335(a), has been in the statute since 1952.

USCIS says that by 1991 the former INS had stopped doing them and relied almost entirely on FBI criminal history and other security checks. The new guidance ends the general waiver. A USCIS directorate decides case by case, or by class of cases, whether to investigate or waive.

1. June 27, 1952The Immigration and Nationality Act creates INA 335, allowing investigation of naturalization applicants.
2. By 1991The INS abandons neighborhood investigations, according to USCIS.
3. August 22, 2025Policy Memorandum PM-602-0189 resumes personal investigations. USCIS says it has conducted “a number of” them since then.
4. August 25, 2026PA-2026-10 writes the practice into the Policy Manual, effective immediately for pending and new N-400s.

Source: USCIS Policy Alert PA-2026-10, pages 1–4.

Where do investigators go, and what do they ask?

The investigation should cover at least the 5 years before you filed. It can be shorter for some spouses and military applicants, or longer and outside the United States when needed. Investigators must identify themselves as USCIS employees, explain why they’re there, and limit questions to what witnesses know personally.

The Policy Manual lists 13 topics an investigator may gather information on:

• Family status, marriages and children
• Social activities, associations and habits
• Employment, unemployment and businesses
• Financial obligations
• Schools attended
• Reputation in the community
• Criminal history
• Military service, in the U.S. or abroad
• Travel outside the United States
• Activities and residences abroad
• Current and past residences
• Credibility and truthfulness
• Attachment to the United States and the Constitution

For applicants without a stable address, such as people who are homeless or living in a shelter, investigators may use shelter or social-service records and letters instead of talking to neighbors. Confidentiality rules for Violence Against Women Act (VAWA), T and U cases still apply.

How can character letters help you avoid a neighborhood investigation?

Letters are optional, but the guidance makes them important. USCIS says proactively submitting at least two letters with Form N-400 can help it decide whether a waiver is appropriate. It also says that failing or refusing to provide them “may contribute” to a decision to investigate. Letters from immediate family or relatives aren’t considered. USCIS prefers U.S. citizens who know you personally, such as neighbors, employers, coworkers or business associates. Use the checklist to see whether a draft letter covers what USCIS asks for:

Checklist items from USCIS Policy Manual, Vol. 12, Part B, Ch. 2, Section A.4. Nothing you tick is saved.

Military applicants filing under INA 328 or 329 get their service weighed in the waiver decision. And a missing letter alone can’t support a finding that you lack good moral character.

What does USCIS data show about N-400 processing?

USCIS’s quarterly data shows a sharp slowdown since mid-2025. We can’t say how much of it comes from neighborhood investigations. Other USCIS policy changes took effect over the same period, and USCIS doesn’t report how many investigations it has done. (A further change, the November 2026 good moral character memo, came after this data.)

Between the quarter ending September 2025 and the quarter ending June 2026, by our arithmetic:

• Pending general N-400s rose by 202,399, or 38.6%.
• The median processing time went from 5.7 to 9.5 months, 3.8 months longer.
• Approvals per quarter fell 74%, while the denied share of decisions roughly doubled, from 9.4% to 18.6%.

For how processing times work more broadly, see our guide to USCIS processing times in 2026.

Who is most likely to notice the change?

• Applicants who moved or changed jobs often. Each address and employer in the statutory period is a place an investigator may check against your N-400.
• Self-employed applicants and business owners. The guidance names clients, customers and contractors as possible witnesses.
• Applicants without many U.S. citizen contacts. Letters from non-citizens aren’t excluded, but USCIS says it prefers citizens.
• Applicants with anything in their history to explain. USCIS can request an investigation at any time before the oath, including after the interview, if questions or derogatory information come up.

What can N-400 applicants do now?

1. Make your residence and job history exact. Use the same dates and addresses that appear in leases, pay records and tax returns.
2. Line up two or more letter writers early. Pick people outside your family who know you well, and share the checklist above.
3. File the letters with the N-400. The guidance speaks of submitting them proactively with the application.
4. Answer requests for more evidence on time. Failing to reply to a request tied to the waiver decision can count toward ordering an investigation.
5. Get advice if something in your past needs context. If USCIS intends to rely on derogatory information from an investigation, it must give you notice and a chance to rebut it. Our N-400 guide covers the issues that most often lead to denials.

What is still unclear?

• How often USCIS waives. USCIS hasn’t published how many investigations it has ordered or waived.
• Timing. The Manual says investigations generally finish before the interview, but it doesn’t say how long they take or whether they’ll push back interview scheduling.
• Which classes of cases are waived. USCIS may waive by class, but it hasn’t listed any classes publicly.

Frequently asked questions