Gulf War syndrome VA rating: fibromyalgia, chronic fatigue, and undiagnosed illness

For veterans who served in Southwest Asia, the VA presumes that a cluster of hard-to-explain conditions came from service. Fibromyalgia and chronic fatigue syndrome are the two named ones, and they are rated on their own codes. Symptoms that never got a diagnosis at all can be rated too.

Last reviewed October 2026 · Not legal advice, VA.gov always controls

VA has no single rating or percentage for Gulf War syndrome. For qualifying service, the law presumes service connection for an undiagnosed illness or a medically unexplained chronic multisymptom illness such as fibromyalgia, chronic fatigue syndrome, or IBS, and each condition is then rated on its own code: fibromyalgia at 10% to 40%, chronic fatigue syndrome at 10% to 100%, and undiagnosed symptoms by analogy to the closest code (38 U.S.C. § 1117; 38 CFR § 3.317).

The Gulf War presumption

38 CFR § 3.317 presumes service connection for veterans with service in the Southwest Asia theater of operations, Iraq, Kuwait, Saudi Arabia, the neutral zone, Bahrain, Qatar, the UAE, Oman, the Gulf of Aden, the Gulf of Oman, the Persian Gulf, the Arabian Sea, the Red Sea, and the airspace above, at any time on or after August 2, 1990, who have a qualifying chronic disability. The regulation's printed text still requires the disability to have appeared either during that service or to a degree of 10% or more by December 31, 2026, but that text is out of date. Section 405 of the PACT Act (August 10, 2022) rewrote the statute behind it, 38 U.S.C. § 1117: a qualifying chronic disability now counts if it "became manifest to any degree at any time," and service in Afghanistan, Israel, Egypt, Turkey, Syria, or Jordan during the Persian Gulf War now counts too. VA's eligibility page already applies both changes (for those six countries, ground service only, not the airspace), and a 2024 proposed rule would rewrite § 3.317 to match.

A qualifying chronic disability is one of three things:

• An undiagnosed illness: signs and symptoms a doctor cannot attribute to any known clinical diagnosis. The regulation lists examples: fatigue, skin signs, headache, muscle pain, joint pain, neurological and neuropsychological signs, respiratory symptoms, sleep disturbance, gastrointestinal signs, cardiovascular signs, abnormal weight loss, menstrual disorders.
• A medically unexplained chronic multisymptom illness (MUCMI), a diagnosed condition with a cluster of symptoms and no conclusive cause. The regulation gives three examples: chronic fatigue syndrome, fibromyalgia, and functional gastrointestinal disorders including IBS.
• A diagnosed illness the Secretary determines by regulation warrants the presumption. This third category comes from the statute, 38 U.S.C. § 1117(a)(2)(C), not the regulation, and § 3.317(a) currently lists no illness under it.

"Chronic" means the disability has existed for six months or more, or shows intermittent episodes of improvement and worsening over six months. What the presumption removes is the nexus: no in-service event, no medical opinion linking the condition to service. What you still have to prove is the disability itself (a diagnosis for a MUCMI, objective indications of it for an undiagnosed illness) and how severe it is.

Separately, § 3.317(c) presumes service connection for nine infectious diseases: brucellosis, Campylobacter jejuni, Q fever, malaria, tuberculosis, nontyphoid Salmonella, Shigella, visceral leishmaniasis, and West Nile virus. That presumption has its own timing rule. Most of these must appear to a degree of 10% or more within one year of leaving qualifying service, malaria can also qualify if its incubation period began during that service, and only visceral leishmaniasis and tuberculosis have no time limit.

Fibromyalgia: DC 5025

Rated in § 4.71a. The code requires widespread musculoskeletal pain and tender points, with or without fatigue, sleep disturbance, stiffness, paresthesias, headache, IBS symptoms, depression, anxiety, or Raynaud's-like symptoms.

The note defines widespread pain as pain on both sides of the body, above and below the waist, and affecting both the axial skeleton and the extremities. The 40% tier is the ceiling, and the word that reaches it is refractory: treatment has been tried and has not controlled the symptoms. A rheumatology record documenting the medications attempted and the result is the evidence. A record showing one medication, taken continuously, that keeps the symptoms under control matches the 10% description; a record showing four medications tried and constant symptoms anyway matches the 40% description.

Chronic fatigue syndrome: DC 6354

Rated in § 4.88b. The criteria measure how much debilitating fatigue and cognitive impairment restrict routine daily activities relative to your pre-illness level, or alternatively how many weeks per year you are incapacitated (bed rest and treatment prescribed by a physician).

Symptoms controlled by continuous medication also meet 10%, whichever pattern they follow. "Pre-illness level" is a comparison, which means the record needs a before and an after. A statement from you and from someone who knew you describing what a normal week looked like before and what it looks like now is exactly what the tier asks for. For the incapacitation route, every period of prescribed bed rest needs to be in a medical record.

Undiagnosed illness: rating by analogy

Symptoms with no diagnosis are rated under the code for the body system they most resemble. The regulation, § 3.317(a)(5), lets the rater borrow the criteria for any condition with similar functions affected, a similar anatomical location, or similar symptoms, so joint pain points toward the joint codes and digestive symptoms toward the digestive codes. The rater picks the closest code and applies its criteria to your symptoms. What you need is a record of the symptoms over time, an examiner's confirmation that no diagnosis accounts for them, and evidence of severity in the terms of whichever code applies.

Where these claims fail

• The examiner assigns a diagnosis. If the Gulf War general medical exam attributes your symptoms to a known condition with a known cause, the presumption falls away and you are back to needing a nexus for that condition. The exam is not the only evidence, though: VA has to consider all the lay and medical evidence of record, so a treating specialist's opinion that the diagnosis does not account for the symptoms is weighed against the examiner's.
• Six months is not documented. The chronicity requirement needs records spanning six months or more. A single visit does not establish a chronic disability.
• Location is not proven. The presumption is geographic. Deployment orders, the DD-214, awards that require theater service, or personnel records showing dates in a covered country are the proof. Ships in the Persian Gulf count, and since the PACT Act so does ground service in Afghanistan, Israel, Egypt, Turkey, Syria, or Jordan; the airspace over those six does not.

Combined with the rest

Fibromyalgia, CFS, and IBS can each be rated separately where the symptoms are distinct, and all three are MUCMIs. A 40% fibromyalgia rating and a 40% CFS rating combine to 64%, which rounds to 60%. A veteran with severe Gulf War illness across several systems can reach a high combined rating, and if the conditions together prevent work, the path to the 100% rate is TDIU. The combined rating guide walks through the arithmetic.

The checklist

1. Proof of service in a covered location (the Southwest Asia theater or one of the six PACT Act countries) with dates.
2. Records documenting the symptoms for six months or more.
3. For fibromyalgia: a rheumatology or primary-care diagnosis and the treatment history showing what was tried.
4. For CFS: a diagnosis, a before-and-after description of daily activity from you and someone who knows you, and any prescribed bed rest.
5. For undiagnosed symptoms: a statement listing each symptom with onset and frequency, and any workup that ruled out known causes.
6. A symptom log covering the last several months.

Sources

• 38 CFR § 3.317, Compensation for certain disabilities occurring in Persian Gulf veterans: the presumption itself, the MUCMI definition, the six-month chronicity rule, the exclusions, and the Southwest Asia theater list.
• 38 U.S.C. § 1117, as amended by Pub. L. 117-168, § 405: the statute, which now allows a qualifying chronic disability that became manifest to any degree at any time and adds six countries to the definition of a Persian Gulf veteran.
• 89 FR 79815 (Oct. 1, 2024), proposed rule on toxic exposure claims: VA's plan to rewrite § 3.317 to match the PACT Act changes.
• VA.gov, Gulf War illnesses linked to Southwest Asia service: VA's current list of covered locations, including which airspace counts.
• 38 CFR § 4.71a, Diagnostic Code 5025: the fibromyalgia tiers and the definition of widespread pain.
• 38 CFR § 4.88b, Diagnostic Code 6354: the chronic fatigue syndrome tiers and the rule that incapacitation requires prescribed bed rest.
• 38 CFR § 4.25, Combined ratings table: how separate ratings combine and round to the nearest 10.
• 38 CFR § 4.16, Total disability ratings based on unemployability: when VA pays at the 100% rate because service-connected conditions prevent substantially gainful work.
• 38 U.S.C. § 1120(b): the PACT Act's burn pit list, which does not include fibromyalgia or chronic fatigue syndrome.
• 38 U.S.C. § 5107, Claimant responsibility; benefit of the doubt: the rule that VA considers all lay and medical evidence of record, and gives the claimant the benefit of the doubt when the positive and negative evidence are in approximate balance.