ICD-10-CM 2027 diagnosis code
E88.01Alpha-1-antitrypsin deficiency
E88.01 is a valid, billable ICD-10-CM code for alpha-1-antitrypsin deficiency. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About E88.01
E88.01 is the ICD-10-CM diagnosis code for Alpha-1-antitrypsin deficiency. It belongs to category E88 (other and unspecified metabolic disorders), block E70-E88 (metabolic disorders) and chapter 4 (endocrine, nutritional and metabolic diseases). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
Within E88.0 (disorders of plasma-protein metabolism, not elsewhere classified), E88.01 is specifically for Alpha-1-antitrypsin deficiency. Related codes cover Plasminogen deficiency (E88.02) and other disorders of plasma-protein metabolism, not elsewhere classified (E88.09).
Use an additional code for: codes for associated conditions.
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 642 (Inborn and Other Disorders of Metabolism, relative weight 1.3219), 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.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Before ICD-10, this condition was coded in ICD-9-CM as 273.4 (Alpha-1-antitrypsin deficiency).
Coding notes
- AAT deficiency
Notes that apply from higher levels
Instructions written at a parent level also apply to E88.01.
› From E88 Other and unspecified metabolic disorders
- histiocytosis X (chronic) (C96.6)
- codes for associated conditions
Broader instructions also apply from E70-E88 Metabolic disorders and Chapter 4: Endocrine, nutritional and metabolic diseases.
Alphabetic index entries
2 entriesTerms in the official ICD-10-CM index that lead to E88.01.
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC 10 · Endocrine, Nutritional and Metabolic Diseases and Disorders
ICD-9-CM equivalent
Converter →- 273.4Alpha-1-antitrypsin deficiencyexact
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about E88.01
Is E88.01 billable?
- Yes. E88.01 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can E88.01 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict E88.01 as a principal diagnosis.
Is E88.01 a CC or MCC?
- No. E88.01 is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does E88.01 group to?
- E88.01 is used in the MS-DRG v44.0 logic for MS-DRG 642 (Inborn and Other Disorders of Metabolism). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.
What is the ICD-9 code for E88.01?
- The CMS General Equivalence Mappings map E88.01 to ICD-9-CM 273.4.