ICD-10-CM 2027
ICD-10 code for Marfan syndrome
From the official ICD-10-CM alphabetic index entry “Syndrome › Marfan”. Page updated September 29, 2026.
About coding Marfan syndrome
The ICD-10-CM code for Marfan syndrome is Q87.40 (Marfan syndrome, unspecified). The official index lists 4 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on Q87.40.
Within Q87.4, choose Q87.40 (unspecified) only when documentation doesn't support a more specific option: with cardiovascular manifestations (Q87.41), with ocular manifestations (Q87.42) and with skeletal manifestation (Q87.43).
Use an additional code(s) to identify all associated manifestations.
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.
More specific Marfan syndrome codes (official index)
- with
- cardiovascular manifestations Q87.418 — Marfan syndrome with other cardiovascular manifestations
- aortic dilation Q87.410 — Marfan syndrome with aortic dilation
- ocular manifestations Q87.42 — Marfan syndrome with ocular manifestations
- skeletal manifestations Q87.43 — Marfan syndrome with skeletal manifestation
Common questions about Marfan syndrome ICD-10 codes
What is the ICD-10 code for Marfan syndrome?
- Q87.40 — Marfan syndrome, unspecified. More specific codes apply when the documentation supports them: Q87.418, Q87.410, Q87.42, Q87.43.
Is Q87.40 billable?
- Yes. Q87.40 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can Q87.40 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict Q87.40 as a principal diagnosis.
Is Q87.40 a CC or MCC?
- Q87.40 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.