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ICD-10-CM 2027

ICD-10 code for Mucoviscidosis

E84.9

Cystic fibrosis, unspecified

✓ Billable / specificCC — complication/comorbidity

From the official ICD-10-CM alphabetic index entry “Mucoviscidosis”. Page updated September 29, 2026.

About coding Mucoviscidosis

The ICD-10-CM code for Mucoviscidosis is E84.9 (Cystic fibrosis, unspecified). The official index lists 1 more specific code, 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 Mucoviscidosis codes (official index)

  • with meconium obstruction E84.11 — Meconium ileus in cystic fibrosis

Common questions about Mucoviscidosis ICD-10 codes

What is the ICD-10 code for Mucoviscidosis?

E84.9 — Cystic fibrosis, unspecified. More specific codes apply when the documentation supports them: E84.11.

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.