Disabled Veterans are entitled to Social Security Disability Insurance (SSDI), but they still must meet Social Security’s definition of disability. Basically, if a Veteran is unable to work for physical or emotional reasons, and for at least a year, they may be eligible to receive benefits. Even if the service member receives pay they still may be eligible.
Social Security stresses that their rules are different from other government agencies. SSDI provides benefits for veterans who are 100% disabled but, does not provide for partial disability. So, if another agency says the Veteran is disabled, Social Security may deny benefits if the disability doesn’t meet their requirements.
You can get more information at Social Security Online.