ICD-10-CM 2027 diagnosis code
E20.0Idiopathic hypoparathyroidism
E20.0 is a valid, billable ICD-10-CM code for idiopathic hypoparathyroidism. 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 E20.0
E20.0 is the ICD-10-CM diagnosis code for idiopathic hypoparathyroidism. It belongs to category E20 (hypoparathyroidism), block E20-E35 (disorders of other endocrine glands) 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 E20 (hypoparathyroidism), E20.0 is specifically for idiopathic hypoparathyroidism. Related codes cover Pseudohypoparathyroidism (E20.1), other hypoparathyroidism (E20.8) and unspecified (E20.9).
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 643 (Endocrine Disorders with MCC, relative weight 1.6139), DRG 644 (Endocrine Disorders with CC, relative weight 1.0044), DRG 645 (Endocrine Disorders without CC/MCC, relative weight 0.7459), DRG 791 (Prematurity with Major Problems, relative weight 4.1075) and DRG 793 (Full Term Neonate with Major Problems, relative weight 4.2195), in MDC 10 (Endocrine, Nutritional and Metabolic Diseases and Disorders) and MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period), 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 252.1 (hypoparathyroidism).
Notes that apply from higher levels
Instructions written at a parent level also apply to E20.0.
› From E20 Hypoparathyroidism
Broader instructions also apply from E20-E35 Disorders of other endocrine glands and Chapter 4: Endocrine, nutritional and metabolic diseases.
Alphabetic index entries
1 entriesTerms in the official ICD-10-CM index that lead to E20.0.
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
MDC 15 · Newborns and Other Neonates with Conditions Originating in the Perinatal Period
MDC 15 · Newborns and Other Neonates with Conditions Originating in the Perinatal Period
ICD-9-CM equivalent
Converter →- 252.1Hypoparathyroidismapproximate
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 E20.0
Is E20.0 billable?
- Yes. E20.0 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can E20.0 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict E20.0 as a principal diagnosis.
Is E20.0 a CC or MCC?
- No. E20.0 is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does E20.0 group to?
- E20.0 is used in the MS-DRG v44.0 logic for MS-DRG 643 (Endocrine Disorders with MCC), MS-DRG 644 (Endocrine Disorders with CC), MS-DRG 645 (Endocrine Disorders without CC/MCC), MS-DRG 791 (Prematurity with Major Problems) and MS-DRG 793 (Full Term Neonate with Major Problems). 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 E20.0?
- The CMS General Equivalence Mappings map E20.0 to ICD-9-CM 252.1.