ICD-10 code for Thiamin deficiency

The ICD-10-CM code for Thiamin deficiency is E51.9 (Thiamine deficiency, unspecified). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on E51.9.

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.