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ICD-10-CM 2027 diagnosis code

E87.1Hypo-osmolality and hyponatremia

✓ Billable / specificCC — complication/comorbidity

E87.1 is a valid, billable ICD-10-CM code for hypo-osmolality and hyponatremia. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Looking up by condition? See ICD-10 code for Hyponatremia, ICD-10 code for Hypo-osmolality, ICD-10 code for Salt or sodium depletion.

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 E87.1

E87.1 is the ICD-10-CM diagnosis code for Hypo-osmolality and hyponatremia. It belongs to category E87 (other disorders of fluid, electrolyte and acid-base balance), 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 E87 (other disorders of fluid, electrolyte and acid-base balance), E87.1 is specifically for Hypo-osmolality and hyponatremia. Related codes cover Hyperosmolality and hypernatremia (E87.0), acidosis (E87.2), Alkalosis (E87.3), mixed disorder of acid-base balance (E87.4), Hyperkalemia (E87.5), Hypokalemia (E87.6), fluid overload (E87.7) and other disorders of electrolyte and fluid balance, not elsewhere classified (E87.8).

Don't report E87.1 together with the conditions in its Excludes1 note: syndrome of inappropriate secretion of antidiuretic hormone (E22.2).

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 640 (Miscellaneous Disorders of Nutrition, Metabolism, Fluids and Electrolytes with MCC, relative weight 1.3395), DRG 641 (Miscellaneous Disorders of Nutrition, Metabolism, Fluids and Electrolytes without MCC, relative weight 0.7865), 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 276.1 (Hyposmolality and/or hyponatremia).

Coding notes

Applicable toConditions and synonyms classified to this code
  • Sodium [Na] deficiency
Excludes1Not coded here — never report together with this code
  • syndrome of inappropriate secretion of antidiuretic hormone (E22.2)

Notes that apply from higher levels

Instructions written at a parent level also apply to E87.1.

› From E87 Other disorders of fluid, electrolyte and acid-base balance
Excludes1
  • diabetes insipidus (E23.2)
  • electrolyte imbalance associated with hyperemesis gravidarum (O21.1)
  • electrolyte imbalance following ectopic or molar pregnancy (O08.5)
  • familial periodic paralysis (G72.3)
  • metabolic acidemia in newborn, unspecified (P19.9)

Broader instructions also apply from E70-E88 Metabolic disorders and Chapter 4: Endocrine, nutritional and metabolic diseases.

Alphabetic index entries

14 entries

Terms in the official ICD-10-CM index that lead to E87.1.

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 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 →
  • 276.1Hyposmolality and/or hyponatremiaexact

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about E87.1

Is E87.1 billable?

Yes. E87.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can E87.1 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict E87.1 as a principal diagnosis.

Is E87.1 a CC or MCC?

E87.1 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.

What DRG does E87.1 group to?

E87.1 is used in the MS-DRG v44.0 logic for MS-DRG 640 (Miscellaneous Disorders of Nutrition, Metabolism, Fluids and Electrolytes with MCC), MS-DRG 641 (Miscellaneous Disorders of Nutrition, Metabolism, Fluids and Electrolytes without 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 E87.1?

The CMS General Equivalence Mappings map E87.1 to ICD-9-CM 276.1.