Service connection is the legal finding that your disability is linked to your military service. Without it, there is no rating and no compensation. Under 38 CFR Part 3, there are several distinct ways to establish it.
The five pathways
- Direct (§ 3.303): the condition began in or was caused by service.
- Secondary (§ 3.310): a service-connected condition caused or aggravated another.
- Presumptive (§§ 3.307/3.309 + PACT Act): the law presumes a link for certain exposures and conditions.
- Aggravation (§ 3.306): service permanently worsened a pre-existing condition.
- Section 1151: injury caused by VA medical care.
Why this matters
Many veterans only try the direct route, get denied, and give up — when a secondary or presumptive pathway would have won. Part 3 gets you in the door; Part 4 (the rating schedule) decides the percentage once you are connected.

