ICD-10-CM 2027
ICD-10 code for cystic fibrosis
From the official ICD-10-CM alphabetic index entry “Fibrosis, fibrotic › cystic (of pancreas)”. Page updated September 29, 2026.
About coding cystic fibrosis
The ICD-10-CM code for cystic fibrosis is E84.9 (Cystic fibrosis, unspecified). The official index lists 5 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on E84.9.
Within E84, choose E84.9 (unspecified) only when documentation doesn't support a more specific option: with pulmonary manifestations (E84.0), with intestinal manifestations (E84.1) and with other manifestations (E84.8).
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) and DRG 641 (Miscellaneous Disorders of Nutrition, Metabolism, Fluids and Electrolytes without MCC, relative weight 0.7865), 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.
More specific cystic fibrosis codes (official index)
- with
- distal intestinal obstruction syndrome E84.19 — Cystic fibrosis with other intestinal manifestations
- fecal impaction E84.19 — Cystic fibrosis with other intestinal manifestations
- intestinal manifestations NEC E84.19 — Cystic fibrosis with other intestinal manifestations
- pulmonary manifestations E84.0 — Cystic fibrosis with pulmonary manifestations
- specified manifestations NEC E84.8 — Cystic fibrosis with other manifestations
Common questions about cystic fibrosis ICD-10 codes
What is the ICD-10 code for cystic fibrosis?
- E84.9 — Cystic fibrosis, unspecified. More specific codes apply when the documentation supports them: E84.19, E84.19, E84.19, E84.0 and others below.
Is E84.9 billable?
- Yes. E84.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can E84.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict E84.9 as a principal diagnosis.
Is E84.9 a CC or MCC?
- E84.9 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.