Becoming a Navy SEAL requires meeting physical, educational, mental, and security standards. Candidates must be U.S. citizens between 18 and 28 years old (with rare waivers up to 30), have a high school diploma or equivalent, pass a Top Secret/Sensitive Compartmented Information (TS/SCI) security clearance, and have uncorrected vision no worse than 20/40 in each eye (correctable to 20/20). They must pass a Naval Special Warfare Physical Screening Test (PST) including 500-yard swim, push-ups, sit-ups, pull-ups, and a 1.5-mile run within competitive times. Medical requirements include normal color vision, passing SEAL-specific medical evaluations, and being in excellent cardiovascular health. Candidates also need a valid Secret security clearance before entering the training pipeline. Psychological evaluations assess mental toughness and ability to handle extreme stress. Those selected attend Naval Special Warfare Preparation and Conditioning (PrepCourse) before Basic Underwater Demolition/SEAL (BUD/S) training, which is an extremely demanding 24-week course with about 75% attrition. After BUD/S, successful candidates continue through advanced training phases including dive training, parachute training, and advanced warfare tactics. The entire pipeline from entry to becoming a fully qualified SEAL typically takes 2-3 years. Navy enlists individuals as sailors first, so recruits go through basic training before SEAL training. Security clearance disqualification factors include criminal history, drug use, financial irresponsibility, and foreign contacts that raise concerns.