Thiamine deficiency (E51) ICD-10-CM
The E51 code range covers thiamine deficiency with 7 ICD-10-CM diagnosis codes. 5 of them are billable and valid for claim submission in fiscal year 2027, and the category headers group them but cannot themselves be billed.
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
- sequelae of thiamine deficiency E64.8
Codes in the E51 Range 7 codes · 5 billable
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the E51 range.
Beriberi
A disease caused by a deficiency of thiamine (vitamin B1) and characterized by polyneuritis, cardiac pathology, and edema. The epidemic form is found primarily in areas in which white (polished) rice is the staple food, as in Japan, China, the Philippines, India, and other countries of southeast Asia. (Dorland, 27th ed)
Thiamine Deficiency
A nutritional condition produced by a deficiency of THIAMINE in the diet, characterized by anorexia, irritability, and weight loss. Later, patients experience weakness, peripheral neuropathy, headache, and tachycardia. In addition to being caused by a poor diet, thiamine deficiency in the United States most commonly occurs as a result of alcoholism, since ethanol interferes with thiamine absorption. In countries relying on polished rice as a dietary staple, BERIBERI prevalence is very high. (From Cecil Textbook of Medicine, 19th ed, p1171)
Wernicke Encephalopathy
An acute neurological disorder characterized by the triad of ophthalmoplegia, ataxia, and disturbances of mental activity or consciousness. Eye movement abnormalities include nystagmus, external rectus palsies, and reduced conjugate gaze. THIAMINE DEFICIENCY and chronic ALCOHOLISM are associated conditions. Pathologic features include periventricular petechial hemorrhages and neuropil breakdown in the diencephalon and brainstem. Chronic thiamine deficiency may lead to KORSAKOFF SYNDROME. (Adams et al., Principles of Neurology, 6th ed, pp1139-42; Davis & Robertson, Textbook of Neuropathology, 2nd ed, pp452-3)
About the E51 Code Range
Thiamine deficiency is a nutritional condition that can involve weight loss, weakness, and nerve problems.
E51 separates named conditions from other manifestations and unspecified thiamine deficiency. E51.1 identifies beriberi, a condition under thiamine deficiency, with separate codes for dry beriberi (E51.11) and wet beriberi (E51.12). E51.2 identifies Wernicke's encephalopathy, another named condition under thiamine deficiency. E51.8 identifies other manifestations, while E51.9 identifies unspecified thiamine deficiency.
Questions About This Page
How many billable codes are in the E51 range?
Of the 7 codes in this range, 5 are billable and valid for claim submission from October 1, 2026 through September 30, 2027. Category header codes group them but cannot be reported on claims.
What does the E51 range classify?
The range classifies thiamine deficiency. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
