2027 ICD-10-CM Diagnosis Code E16.A1Hypoglycemia level 1

ICD-10-CM Codes›E00–E89›E15-E16›E16

ICD-10-CM E16.A1
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

E16.A1 is a billable ICD-10-CM diagnosis code for hypoglycemia level 1. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 643 through 645. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified endocrine disorders.

Code Identity

ICD-10-CM Code
E16.A1
Billable Status
Yes — Valid for Submission
Code Describes
Hypoglycemia level 1
Short Description
Hypoglycemia level 1
Same as the full description in the CMS dataset.
Parent Code
E16.A
Hypoglycemia level

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE15-E16Other disorders of glucose regulation and pancreatic internal secretion
CategoryE16Other disorders of pancreatic internal secretion
This CodeE16.A1Hypoglycemia level 1

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to E16.A1: its own notes plus those printed at Chapter 4. A note printed at a category, block or chapter applies to every code under it.

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Decreased blood glucose level 1

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From Chapter 4 (E00-E89) Endocrine, nutritional and metabolic diseases applies to 973 codes
  • transitory endocrine and metabolic disorders specific to newborn (P70-P74)

Notes

General instructions on how these codes are used.

From Chapter 4 (E00-E89) Endocrine, nutritional and metabolic diseases applies to 973 codes
  • All neoplasms, whether functionally active or not, are classified in Chapter 2. Appropriate codes in this chapter (i.e. E05.8, E07.0, E16-E31, E34.-) may be used 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.

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name E16.A1, its category, or a range that includes it.

Code First 1

These codes say to code first a condition named in the note, and E16.A1 is one of the conditions named.

  • G63 Polyneuropathy in diseases classified elsewhere
    endocrine disease, except diabetes (E00-E07, E15-E16, E20-E34) names E15-E16, which includes this code

Use Additional Code 9

These codes say to use an additional code from the note, and E16.A1 is one of the codes named.

  • E08.64 Diabetes mellitus due to underlying condition with hypoglycemia
    code for hypoglycemia level, if applicable (E16.A-) names E16.A-, which includes this code
  • E09.64 Drug or chemical induced diabetes mellitus with hypoglycemia
    code for hypoglycemia level, if applicable (E16.A-) names E16.A-, which includes this code
  • E10.64 Type 1 diabetes mellitus with hypoglycemia
    code for hypoglycemia level, if applicable (E16.A-) names E16.A-, which includes this code
  • E11.64 Type 2 diabetes mellitus with hypoglycemia
    code for hypoglycemia level, if applicable (E16.A-) names E16.A-, which includes this code
  • E13.64 Other specified diabetes mellitus with hypoglycemia
    code for hypoglycemia level, if applicable (E16.A-) names E16.A-, which includes this code
  • E16.0 Drug-induced hypoglycemia without coma
    code for hypoglycemia level, if applicable (E16.A-) names E16.A-, which includes this code
  • E16.1 Other hypoglycemia
    code for hypoglycemia level, if applicable (E16.A-) names E16.A-, which includes this code
  • E16.2 Hypoglycemia, unspecified
    code for hypoglycemia level, if applicable (E16.A-) names E16.A-, which includes this code
  • E89.83 Postprocedural hypoglycemia following a procedure
    code, if known, for hypoglycemia level (E16.A-) names E16.A-, which includes this code

Notes 1

These notes mention E16.A1.

  • Chapter 4 (E00-E89) Endocrine, nutritional and metabolic diseases
    All neoplasms, whether functionally active or not, are classified in Chapter 2. Appropriate codes in this chapter (i.e. E05.8, E07.0, E16-E31, E34.-) may be used 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. names E16-E31, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR END015
Other specified and unspecified endocrine disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Hypoglycemia

Blood glucose, or blood sugar, is the main sugar found in your blood. It is your body's primary source of energy. It comes from the food you eat. Your body breaks down most of that food into glucose and releases it into your bloodstream. When your blood glucose goes up, it signals your pancreas to release insulin.

The full article covers:

  • What is blood glucose?
  • What is hypoglycemia?
  • What causes hypoglycemia?
  • What are the symptoms of hypoglycemia?
  • How is hypoglycemia diagnosed?
  • What are the treatments for hypoglycemia?
  • Can hypoglycemia be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code History & ChangesHistory

Replacement E16.A1 replaces the following previously assigned code(s):

  • E16.2 - Hypoglycemia, unspecified
FY 2025AddedAdded to the ICD-10-CM code setEffective October 1, 2024.
FY 2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About E16.A1Overview

What is the ICD-10 code for hypoglycemia level 1?

The ICD-10-CM code for hypoglycemia level 1 is E16.A1 (sometimes written as E16A1). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is E16.A1 (Hypoglycemia level) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report hypoglycemia level 1 on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does E16.A1 group to?

When hypoglycemia level 1 is the principal diagnosis on an inpatient stay, it groups to MS-DRG 644, 645, 643, with relative weights from 0.7461 to 1.6138 depending on complications. Higher weights mean higher Medicare reimbursement.