How to file a VA PTSD claim (foundational mental-health claim)

5-step Schema.org HowTo for PTSD — 2nd most-claimed VA SC condition. Combat-zone auto-verification (38 CFR 3.304(f)(3)). MST stressor + "marker" doctrine (38 CFR 3.304(f)(5) + 38 USC 1720D). Rated 0-100% (38 CFR 4.130). CRITICAL: do NOT minimize at C&P exam. VA Form 21-0781 (combat) or 21-0781a (MST). Secondary cascade: sleep apnea (50% if CPAP), depression, anxiety, ED+SMC-K, hypertension, migraines, IBS — compounds to 80-100% combined rating + TDIU eligibility.