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.
