All Singapore male adults (citizens/PRs) are required to serve in the NS unless exempted, as mentioned in the Enlistment Act.
Male applicants who obtained PR status due to sponsorship from their parents in the PR application must register for the National Service after reaching 16 years. They will be enlisted after reaching the age of 18 years at the earliest chance. Ministry of Defense may also grant deferment from serving full-time National Service if you pursue full-time studies and meet the required criteria. All NS-liable males traveling to foreign countries for more than three months must obtain an EP (Exit Permit) if they are 13 years or above.
Once they finish the service, they must complete ORNS (Operational Ready National Service) every year for up to 40 days. The ORNS training cycle duration keeps going until they turn 40 (50 in the case of army officers).
Only the principal applicants who received their PR status under the GIP or PTS schemes are not liable for NS.
Serving in National Services is crucial for PRs. If you lose or renounce your PR status without finishing your National Service, you may also lose any future opportunities to study or work in the city-state. There is almost a certainty that you will not be able to obtain Singapore PR status in the future. You may also put in danger future application renewals of re-entry Permits for not just you but also for your sponsors.