---
title: "ICD-10-CM E87.21: Acute metabolic acidosis | BillingBrief"
description: "ICD-10-CM code E87.21: Acute metabolic acidosis. Category, related codes, and the official source, in plain English."
canonical: "https://billingbrief.com/icd10/e87.21/"
language: "en"
---

# E87.21 Acute metabolic acidosis

ICD-10-CM · [CMS code reference](#source)

**Official ICD-10-CM description:** Acute metabolic acidosis

## Coding notes

From the ICD-10-CM FY2027 (effective October 1, 2026) tabular list. Notes on a parent code or category apply here too.

### Also covers

-   Acute lactic acidosis

### Excludes1

Not coded together with this code. The exception is when the two conditions are unrelated to each other.

-   diabetic acidosis - see categories E08-E10, E11, E13 with ketoacidosis
-   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)
-   androgen insensitivity syndrome (E34.5-)
-   congenital adrenal hyperplasia (E25.0)
-   hemolytic anemias attributable to enzyme disorders (D55.-)
-   Marfan syndrome (Q87.4-)
-   5-alpha-reductase deficiency (E29.1)

### Excludes2

Not part of this code, but both can be coded when both are documented.

-   Ehlers-Danlos syndromes (Q79.6-)

## Related codes

-   [`E87.0` Hyperosmolality and hypernatremia ICD-10-CM](https://billingbrief.com/icd10/e87.0/)
-   [`E87.1` Hypo-osmolality and hyponatremia ICD-10-CM](https://billingbrief.com/icd10/e87.1/)
-   [`E87.20` Acidosis, unspecified ICD-10-CM](https://billingbrief.com/icd10/e87.20/)
-   [`E87.22` Chronic metabolic acidosis ICD-10-CM](https://billingbrief.com/icd10/e87.22/)
-   [`E87.29` Other acidosis ICD-10-CM](https://billingbrief.com/icd10/e87.29/)
-   [`E87.3` Alkalosis ICD-10-CM](https://billingbrief.com/icd10/e87.3/)
-   [`E87.4` Mixed disorder of acid-base balance ICD-10-CM](https://billingbrief.com/icd10/e87.4/)
-   [`E87.5` Hyperkalemia ICD-10-CM](https://billingbrief.com/icd10/e87.5/)

## Common questions

### Is E87.21 a billable code?

Yes. E87.21 is a billable ICD-10-CM code in the ICD-10-CM FY2027 (effective October 1, 2026) code set.

## From the source

Official description from [CMS](https://www.cms.gov/medicare/coding-billing/icd-10-codes).
ICD-10-CM FY2027 (effective October 1, 2026).

Code set

ICD-10-CM

Category

E87 Other disorders of fluid, electrolyte and acid-base balance

Chapter

Endocrine, nutritional and metabolic diseases

Billable

Yes

Educational reference only. Not medical, legal, or billing advice. Always check the current official code set and payer policy before you bill. [About BillingBrief and our sources](https://billingbrief.com/about/).