ICD-10 Code for Thiamin deficiency
The ICD-10-CM code for thiamin deficiency is E51.9 — Thiamine deficiency, unspecified. This is the code the Alphabetic Index gives for thiamin deficiency with no further qualifier, valid for FY2027 (October 1, 2026 – September 30, 2027).
E51.9 is billable but unspecified. If the documentation names a type, site or cause, one of the more specific codes below is likely expected.
Which thiamin deficiency code should you use?
The Alphabetic Index lists 2 codes under Thiamin deficiency. Which one applies depends on the qualifier documented in the record — the type, site, cause, or associated condition. Find the qualifier below, then verify the code in the Tabular List before using it.
By type
| specified NEC | E51.8 | Other manifestations of thiamine deficiency |
Index terms and codes are reproduced from the official ICD-10-CM FY2027 release. The Alphabetic Index is a finding aid — a code must always be verified in the Tabular List before it is reported. Data sources