The word covers two separate benefits, and confusing them is common:
- VA disability compensation — a tax-free monthly payment for a condition connected to your service, based on a rating from 0 to 100%.
- VA health care — medical services through the VA system, including neurology and, for some, caregiver support.
You may qualify for one or both. And a point that trips up a lot of retirees: disability compensation is separate from military retirement pay and from Social Security, and it isn't taxed. Being retired does not disqualify you — many retirees receive VA disability compensation on top of their retirement. If a neurologist has urged you toward the VA, that advice is worth following whatever your retirement status.
Every compensation claim comes down to service connection. Ordinarily that means proving three things: a current diagnosis, an in-service event or exposure, and a medical nexus — a doctor's opinion linking the two. Once connected, the condition is assigned a percentage rating that sets the monthly payment, and a veteran whose service-connected conditions prevent them from working may qualify for Total Disability based on Individual Unemployability (TDIU), paid at the 100% rate even if the combined rating is lower (VA.gov).
The reason Parkinson's and essential tremor diverge so sharply is that one of them lets you skip the hardest part of that proof.
For certain exposures, the VA presumes service connection — you don't have to prove the nexus at all. Parkinson's disease is one of those conditions. It is presumptive for:
- Agent Orange exposure — long recognized for service in Vietnam and the Korean Demilitarized Zone, and, under the PACT Act, expanded to additional locations such as Thailand, Laos, Cambodia, Guam and others (VA.gov, Agent Orange presumptive conditions).
- Camp Lejeune water contamination — for service at that base during the qualifying years (1953–1987) (VA.gov, Camp Lejeune).
The PACT Act of 2022 went further, adding Parkinsonism (Parkinson's-like symptoms) to the Agent Orange presumptive list and broadening the qualifying service locations and dates (VA.gov, PACT Act). For a presumptive claim, the proof collapses to two things: a current diagnosis and qualifying service. No nexus letter, no argument about causation.
On rating, Parkinson's is evaluated under Diagnostic Code 8004 (paralysis agitans), with a minimum of 30%. From there the VA rates each residual of the disease separately — tremor, rigidity, slowness, speech and swallowing changes, balance problems and non-motor effects — and combines them, so real-world ratings frequently rise well above the 30% floor (38 CFR Part 4, DC 8004).
Essential tremor sits in a different category. It is not on any presumptive list, so a veteran has to establish service connection the ordinary way. There are three routes:
- Direct service connection — a nexus tying the tremor to an in-service event or exposure.
- Secondary service connection — showing the tremor was caused or worsened by a condition that's already service-connected, such as PTSD or a traumatic brain injury.
- Aggravation — showing that service permanently worsened a tremor that pre-existed it.
Because there's no diagnostic code named for essential tremor, the VA rates it by analogy — hand and arm tremor is commonly rated using a nerve-impairment code, by severity and by whether the dominant or non-dominant side is affected. As with Parkinson's, a veteran left unable to work by the tremor may be considered for TDIU (VA disability for essential tremor).
The claim itself is a standard application — VA Form 21-526EZ, filed online, by mail or in person. Bring your diagnosis and medical records, your service records showing the qualifying location and dates (the linchpin of a presumptive claim), and, for a non-presumptive essential tremor claim, a nexus opinion from your doctor. The VA will usually schedule a Compensation and Pension (C&P) exam to assess the condition's severity. If you were denied years ago, it can be worth filing again — the PACT Act changed the rules, and claims that failed under the old ones may succeed now.
The recurring lesson from veterans who've been through it is simple: the benefit you don't claim is the one you're guaranteed not to get. For Parkinson's especially, the presumptive rules exist precisely because the government accepted the link between toxic exposure and the disease — so a diagnosis plus the right service history is often most of the case already.