If you're a male green card holder applying for citizenship, Selective Service registration is something you need to get right.
Most male immigrants first hear about Selective Service when they start filling out Form N-400. In the current Form N-400 edition, Part 9, Item 22 asks about Selective Service, including whether you were required to register and, if so, whether you registered. Not registering doesn't automatically disqualify you. But you do need to understand where you stand and what USCIS expects before your citizenship application moves forward.
What is Selective Service and why does it affect your N-400?
Selective Service is the U.S. government's system for registering men who could be called for military duty in a national emergency. Registration doesn't mean you're joining the military. It's a legal requirement under federal law (50 U.S.C. § 3802(a)).
Almost all male U.S. residents ages 18 through 25 must register, including lawful permanent residents, refugees, asylees, and undocumented immigrants. However, males who maintain valid nonimmigrant status through age 26 are exempt from Selective Service registration.
Why does this matter for your N-400? USCIS looks at whether you registered when evaluating your good moral character, which is a core citizenship requirement. Not registering isn't a permanent bar to citizenship. But if you're between 26 and 31 and didn't register, USCIS will want a believable explanation (USCIS Policy Manual, Vol. 12, Part D, Ch. 7).
Not Sure If You Qualify for Citizenship?
Answer a few quick questions to check whether you meet the requirements for naturalization, including Selective Service.
Who must register and who is exempt
Not everyone needs to register.
Must register:
- Almost all male U.S. residents ages 18 to 25, except those who maintain valid nonimmigrant status through age 26
- Lawful permanent residents
- Refugees and asylees
- Undocumented immigrants
- DACA recipients
- Men whose nonimmigrant visas expired more than 30 days ago before age 26
Exempt from registration:
- Males on valid nonimmigrant visas (F-1, H-1B, J-1, etc.) who maintained valid status through age 26
- Males who were not in the U.S. between ages 18 and 26
- Women, regardless of immigration status
- Active duty military members who served continuously from 18 to 26
(SSS — Immigrants and Dual Nationals)
Common misconception: Filing Form I-485 is supposed to automatically register you through a data sharing agreement between USCIS and SSS. That doesn't always happen. Always check your registration at sss.gov/verify or call (847) 688-6888 before filing your N-400.
If you're still between 18 and 25, register now at sss.gov/register. You can register online, by mail using SSS Form 1, or at any U.S. Post Office.
What happens if you didn't register: the age-based framework
USCIS uses a three-tier system based on your age when you file the N-400 (USCIS Policy Manual, Vol. 12, Part D, Ch. 7). What matters is how old you are now.
Under 26: You can still register. Do it before you file. Once you have your Selective Service number, put it on your N-400 and move on. Register at sss.gov/register.
Ages 26 to 31: You can no longer register after 26 (SSS — Men 26 and Older). You'll need to request a Status Information Letter (SIL) from the Selective Service System, write a sworn declaration explaining why you didn't register, and provide supporting evidence that your failure was not "knowing and willful" (50 U.S.C. § 3811(g)).
Over 31: Selective Service non-registration falls outside your good moral character evaluation period. You don't need a SIL, and USCIS can't hold it against you. File your N-400 application normally.
How to get a Status Information Letter (SIL)
If you're 26 to 31 and didn't register, request a SIL before your interview. Two options:
- Online: sss.gov/status-information-letter-sil
- By mail: Send a completed SIL request to Selective Service System, ATTN: SIL, P.O. Box 94638, Palatine, IL 60094-4638
The SIL will confirm one of three things: you were registered, you were not registered, or you were not required to register. If you were required to register but did not, submit a sworn written statement explaining why you did not register. If the SIL shows you were registered or not required to register, you should provide the SIL and any supporting evidence relevant to that finding.
In your statement, you want to show that you didn't skip registration on purpose. Common explanations: you didn't know the requirement existed, you came to the U.S. as a minor and nobody told you, or you assumed your I-485 filing had registered you automatically.
Bring your SIL, your sworn statement, and any supporting documents to your citizenship interview. Go through the full N-400 document checklist and prepare your interview materials ahead of time. The USCIS officer will evaluate your evidence using a "preponderance of the evidence" standard.
The new automatic registration law (effective December 2026)
On December 18, 2025, President Trump signed the FY2026 NDAA into law. Section 535 requires the Selective Service System to automatically register eligible males ages 18 to 26 using federal databases, effective December 18, 2026.
This is the first major change to Selective Service since registration resumed in 1980. Men won't need to self-register anymore. The government will handle it using existing records.
But this does not help men who already missed the window. If you were between 18 and 25 before December 2026 and didn't register, the old rules still apply. USCIS hasn't issued any transitional guidance yet.
Official sources
This guide is based on current USCIS policy and federal regulations. All information was verified against these official sources as of March 2026:
USCIS resources
Selective Service System
Federal statutes
Immigration law changes frequently. We monitor USCIS policy updates and revise this guide when regulations change.