Claim Raven explanation
What this means
This rule covers specified leukemias, multiple myelomas including MGUS, myelodysplastic syndromes, and myelofibrosis in covered veterans. It uses the qualifying-service definition in section 3.320a.
The presumption depends on the diagnosed disorder and qualifying service. The regulation also identifies exceptions where affirmative evidence shows a different cause or other circumstances that defeat the presumption.
How this helps your claim
A hematologist's precise diagnosis and a clear service timeline are more useful than describing the condition only as abnormal bloodwork. Compare any denial with the specific disease list and covered-service definition.
What to check in your records
Use your decision, examination reports, and relevant records to check the following points.
- Obtain hematology, pathology, and diagnostic records naming the disorder.
- Confirm qualifying service using the locations and dates in section 3.320a.
- Check whether VA considered this disease-specific presumption and explained any exception it applied.
Read the specialist diagnosis rather than a broad label
Blood and bone-marrow disorders can have similar-sounding names while remaining medically distinct. A hematology report or pathology finding can identify which disorder is actually present. A record saying abnormal blood work is not the same as a confirmed listed diagnosis.
This section points to section 3.320a for the covered-service definition. Read that cross-reference as part of the rule, not an optional extra. Keep the diagnostic evidence and qualifying service evidence separate so a decision's stated gap can be identified accurately.
Does the presumption establish the disability percentage too?
No. A presumptive connection and evaluation of severity are different parts of the claim. After the applicable entitlement requirements are met, rating provisions address the condition, treatment and residual effects. The diagnosis should remain accurate throughout both parts of the analysis.
Official regulatory text
38 CFR § 3.320b
eCFR snapshot: September 3, 2026. Layout and spacing are adapted for reading. The full section and its tables are included below.
§ 3.320b Presumptive service connection for leukemias, multiple myelomas, myelodysplastic syndromes, and myelofibrosis.
(a) Presumption of exposure. A covered veteran as defined in § 3.320a(c) shall be presumed to have been exposed to certain toxic substances, chemicals, and airborne hazards, including fine particulate matter, during such service, unless there is affirmative evidence to establish that the veteran was not exposed to any such toxic substances, chemicals, and airborne hazards during that service.
(b) Presumption of service connection. Except as provided in paragraph (c) of this section, the following diseases becoming manifest in a covered veteran, as defined in § 3.320a(c), shall be considered to have been incurred in or aggravated during active military, naval, air, or space service, notwithstanding that there is no record of evidence of such disease during the period of such service:
(1) Acute leukemias.
(2) Chronic leukemias.
(3) Multiple myelomas, including monoclonal gammopathy of undetermined significance (MGUS).
(4) Myelodysplastic Syndromes (MDS).
(5) Myelofibrosis.
(c) Exceptions. A disease listed in paragraph (b) of this section shall not be presumed service connected if there is affirmative evidence that:
(1) The disease was not incurred or aggravated during active military, naval, air, or space service; or
(2) The disease was caused by a supervening condition or event that occurred between the veteran's most recent departure from active military, naval, air, or space service and the onset of the disease; or
(3) The disease is the result of the veteran's own willful misconduct.
(Authority: 38 U.S.C. 501, 1119, 1171, 1172, 1173, 1174)
[90 FR 1901, Jan. 10, 2025]
Related references
- 38 CFR § 3.320a: Bladder and Ureter Cancer Presumptions
- 38 CFR § 4.1: What a VA disability rating measures
- 38 CFR § 3.159: VA duty to assist: records and examinations
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