Male Immigrants, Including Undocumented Teens, Could Face Up to 5 Years in Prison for Failing to Register for U.S. Selective Service at 18

A little-known U.S. law is putting new attention on a high-stakes requirement for immigrant families: most male immigrants living in the United States, including undocumented teens, are required to register with Selective Service after turning 18, and failure to do so can carry a penalty of up to five years in prison and a fine of up to $250,000.

The rule is not new, but it is gaining renewed scrutiny as the federal government prepares to move toward automatic Selective Service registration. The Selective Service System says that on Dec. 18, 2025, the president signed the fiscal year 2026 National Defense Authorization Act into law, mandating automatic registration. The agency says it plans to implement that change by December 2026.

Even before that shift takes effect, though, the legal obligation already exists. According to the Selective Service System, "almost all" male U.S. citizens and male immigrants ages 18 through 25 must register. That includes lawful permanent residents, refugees, asylees, parolees and undocumented immigrants. The main exemption applies to men who are in the United States on a current valid nonimmigrant visa, such as certain student, tourist or diplomatic visas.

For young immigrant men, the timing matters. The Selective Service says registration is generally required within 30 days of a man's 18th birthday. For those who arrive in the United States between ages 18 and 25, the agency says they are generally expected to register within 30 days of entering the country if they are otherwise covered by the law.

The penalty language is stark. The Selective Service System states that if a person is required to register and fails to do so, that failure is a felony punishable by up to five years in prison and/or a fine of up to $250,000. The agency repeats that warning in both its benefits-and-penalties guidance and its public FAQ.

The consequences can go beyond criminal exposure. For immigrant men, failing to register can also damage a future citizenship case. USCIS says it will deny a naturalization application when an applicant refused to register or knowingly and willfully failed to register for Selective Service when required. The agency's naturalization instructions also warn that someone who knowingly and willfully did not register may be unable to show the "attachment to the Constitution" required for citizenship.

That means a requirement many families may never have heard of can follow a young man for years. Selective Service materials aimed at immigration attorneys also say failure to register by age 26 can delay the citizenship process for years for men who were required to sign up and did not.

One important distinction remains: registration with Selective Service is not the same as being drafted into the military. The United States does not currently have an active military draft. The automatic-registration change affects how eligible men are entered into the system, not whether a draft is underway.

Still, the law leaves little room for misunderstanding. A male immigrant who is required to register, including an undocumented teen who turns 18 in the United States, can face serious penalties for failing to do it. With automatic registration on the way, the government may soon make compliance easier. But the legal risk for those who miss the requirement is already written into federal law