E51.9 ICD-10-CA code: Thiamine deficiency, unspecified
E51.9 is the ICD-10-CA code for “Thiamine deficiency, unspecified” in CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026.
Official description
E51.9Thiamine deficiency, unspecified
Short description: Thiamine deficiency unspecified
ICD-10-CA · Canada · Also written E519
Index terms
Entries in CIHI’s alphabetical index that lead to E51.9. Searching the index by the condition the note names is how coders reach this code.
- Aneurin deficiency
- Thiamin deficiency
- Deficiency, deficient, aneurin
- Deficiency, deficient, vitamin (multiple), B1
- Deficiency, deficient, vitamin (multiple), thiamine
- Deficiency, deficient, thiamine, thiaminic (chloride)
Notes for E51.9
As CIHI prints them, with any note E51.9 takes from the headings above it.
Excludes
Conditions classified elsewhere.
- Sequelae of thiamine deficiency (E64.8)From E51 Thiamine deficiency
- Nutritional anaemias (D50-D53)From E50-E64 Other nutritional deficiencies
- Complications of pregnancy, childbirth and the puerperium (O00-O99)symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)transitory endocrine and metabolic disorders specific to fetus and newborn (P70-P74)From Chapter 4: Endocrine, nutritional and metabolic diseases (E00-E90)
Note
- All neoplasms, whether functionally active or not, are classified in Chapter II. Appropriate codes in this chapter (i.e. E05.8)(E07.0) (E16-E31)(E34.-) may be used, if desired, as additional codes to indicate either functional activity by neoplasms and ectopic endocrine tissue or hyperfunction and hypofunction of endocrine glands associated with neoplasms and other conditions classified elsewhere.From Chapter 4: Endocrine, nutritional and metabolic diseases (E00-E90)
Where E51.9 sits
- 1ChapterChapter 4: Endocrine, nutritional and metabolic diseases (E00-E90)
- 2Block E50-E64Other nutritional deficiencies
- 3Category E51Thiamine deficiency
- 4Valid code E51.9Thiamine deficiency, unspecified
Source and release
- Data release
- ICD-10-CA · FY 2026–2027
- Effective date
- Apr 1, 2026
- Publisher
- CIHI
This page is built from the ICD-10-CA catalog that Vero Codes reads when it suggests codes: Canadian Institute for Health Information’s FY 2026–2027 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.
Frequently asked questions
What does ICD-10-CA code E51.9 mean?
E51.9 is the ICD-10-CA code for “Thiamine deficiency, unspecified” in CIHI’s ICD-10-CA FY 2026–2027 release.
Where is E51.9 in ICD-10-CA?
E51.9 sits under E51 Thiamine deficiency, within E50-E64 Other nutritional deficiencies, within Chapter 4: Endocrine, nutritional and metabolic diseases (E00-E90).
What coding notes apply to E51.9?
ICD-10-CA lists Excludes, Note notes for E51.9, including those from the headings it sits under. They are listed on this page with where each one comes from.
Which ICD-10-CA release does this page use?
It uses CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026 to Mar 31, 2027. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.