ICD-10-CM 2027
ICD-10 code for Aneurin deficiency
From the official ICD-10-CM alphabetic index entry “Aneurin deficiency”. Page updated September 29, 2026.
About coding Aneurin deficiency
The ICD-10-CM code for Aneurin deficiency is E51.9 (Thiamine deficiency, unspecified).
Within E51, choose E51.9 (unspecified) only when documentation doesn't support a more specific option: beriberi (E51.1), Wernicke's encephalopathy (E51.2) and other manifestations of thiamine deficiency (E51.8).
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 640 (Miscellaneous Disorders of Nutrition, Metabolism, Fluids and Electrolytes with MCC, relative weight 1.3395) and DRG 641 (Miscellaneous Disorders of Nutrition, Metabolism, Fluids and Electrolytes without MCC, relative weight 0.7865), in MDC 10 (Endocrine, Nutritional and Metabolic Diseases and Disorders), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about Aneurin deficiency ICD-10 codes
What is the ICD-10 code for Aneurin deficiency?
- E51.9 — Thiamine deficiency, unspecified.
Is E51.9 billable?
- Yes. E51.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can E51.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict E51.9 as a principal diagnosis.
Is E51.9 a CC or MCC?
- E51.9 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.