--- title: "Part VIII, Subpart iii, Chapter 1" document: "M-21-1" section: "Part VIII, Subpart iii, Chapter 1" canonical: "https://veteranai.co/va-regulations/m21-1/viii.iii.1" source: "https://www.knowva.ebenefits.va.gov/system/templates/selfservice/va_ssnew/help/customer/locale/en-US/portal/554400000001018/content/554400000177449/M21-1-Part-VIII-Subpart-iii-Chapter-1-Service-Connection-SC-for-Tropical-Diseases" updated: "2026-09-07T14:37:33.446800Z" --- July 29, 2021 ### VIII.iii.1.1.a. Considering SC for a Tropical Disease When deciding any claim for service connection (SC) for a tropical disease included in [38 CFR 3.309(b)](), it is also necessary to consider SC based on * manifestation of the claimed disease during service, and * a presumption that the disease, which was first manifested following discharge from service, is nevertheless related to service. ### VIII.iii.1.1.b. Considering Presumptive SC Once a substantially complete claim is of record, the following conditions apply: * the possibility of entitlement to presumptive SC exists when the Veteran alleges inception within the limiting periods contained in * [38 U.S.C. 1112](), or * [38 U.S.C. 1133](), when appropriate * the Veteran does not need to establish that the disease in question was definitely diagnosed within the presumptive period, and * the evidence should show that manifestations of the condition, disabling to the degree of at least 10 percent, became apparent prior to the expiration of the presumptive period shown in [38 CFR 3.307](). ### VIII.iii.1.1.c. Establishing Presumptive SC for Tropical Diseases Use the table below to determine the service requirements the Veteran must meet before VA may establish presumptive SC for tropical diseases listed in in [38 CFR 3.309(b)]().| **If the Veteran served during …**| **Then …** peacetime before January 1, 1947| the Veteran must have had active continuous service for six months or more under [38 CFR 3.308(b)](). peacetime on or after January 1, 1947, or wartime| the Veteran must have had active, continuous service of 90 days or more under [38 CFR 3.307](). **Note:** In claims based on a period of active duty for training (ADT), there is no presumption of SC for tropical diseases under [38 CFR 3.309(b)]() (see [_Smith (Valerie Y.) v. Shinseki_](), 24 Vet.App. 40, 44 (2010)) _unless_ SC has been established for a disability based on the period of ADT, as described in [M21-1, Part III, Subpart i, 1.A.2.i](). ### VIII.iii.1.1.d. Action to Take if a Tropical Disease Was Treated in Service Follow the instructions in the table below when service records show the Veteran was treated for a tropical disease. | **If the Veteran ...**| **Then ...** files a substantially complete claim for the condition| refer the case to the rating activity. did not file a claim for the condition| solicit a claim. **References:** For more information on * what constitutes a substantially complete claim, see * [M21-1, Part I, Subpart i, 1.A.4.f]() * [M21-1, Part II, Subpart iii, 1.C.1.b](), and * [38 CFR 3.159(a)(3)](), and * soliciting claims for chronic, unclaimed disabilities, see [M21-1, Part II, Subpart iii, 2.G.2](). ### VIII.iii.1.1.e. Action to Take if a Tropical Disease Was Not Treated in Service Even though certain tropical diseases were not treated during service, SC may still be established on a presumptive basis under the provisions of * [38 U.S.C. 1112]() * [38 U.S.C. 1133](), or * [38 U.S.C. 1137](). **Reference:** For more information on the diseases for which SC may be established on a presumptive basis and the service requirements that must be met, see [38 CFR 3.307]().