ICD-10-CM 2027
ICD-10 code for Conn's syndrome
From the official ICD-10-CM alphabetic index entry “Conn's syndrome”. Page updated September 29, 2026.
About coding Conn's syndrome
The ICD-10-CM code for Conn's syndrome is E26.01 (Conn's syndrome).
Within E26.0 (primary hyperaldosteronism), E26.01 is specifically for Conn's syndrome. Related codes cover Glucocorticoid-remediable aldosteronism (E26.02) and other primary hyperaldosteronism (E26.09).
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) and DRG 645 (Endocrine Disorders without CC/MCC, relative weight 0.7459), 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.
Common questions about Conn's syndrome ICD-10 codes
What is the ICD-10 code for Conn's syndrome?
- E26.01 — Conn's syndrome.
Is E26.01 billable?
- Yes. E26.01 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can E26.01 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict E26.01 as a principal diagnosis.
Is E26.01 a CC or MCC?
- No. E26.01 is neither a CC nor an MCC under MS-DRG v44.0.