ICD-10-CM 2027
ICD-10 code for circulatory system complication
From the official ICD-10-CM alphabetic index entry “Complication (s) (from) (of) › circulatory system”. Page updated September 29, 2026.
About coding circulatory system complication
The ICD-10-CM code for circulatory system complication is I99.8 (Other disorder of circulatory system). The official index lists 8 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on I99.8.
Within I99, choose I99.8 (Other disorder of circulatory system) only when documentation doesn't support a more specific option: unspecified disorder of circulatory system (I99.9).
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 302 (Atherosclerosis with MCC, relative weight 1.1984) and DRG 303 (Atherosclerosis without MCC, relative weight 0.6612), in MDC 05 (Diseases and Disorders of the Circulatory System), 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 circulatory system complication codes (official index)
- intraoperative I97.88 — Other intraoperative complications of the circulatory system, not elsewhere classified
- postprocedural I97.89 — Other postprocedural complications and disorders of the circulatory system, not elsewhere classified
- following cardiac surgery I97.190 — Other postprocedural cardiac functional disturbances following cardiac surgery
- postcardiotomy syndrome I97.0 — Postcardiotomy syndrome
- hypertension I97.3 — Postprocedural hypertension
- lymphedema after mastectomy I97.2 — Postmastectomy lymphedema syndrome
- postcardiotomy syndrome I97.0 — Postcardiotomy syndrome
- specified NEC I97.89 — Other postprocedural complications and disorders of the circulatory system, not elsewhere classified
Common questions about circulatory system complication ICD-10 codes
What is the ICD-10 code for circulatory system complication?
- I99.8 — Other disorder of circulatory system. More specific codes apply when the documentation supports them: I97.88, I97.89, I97.190, I97.0 and others below.
What is the ICD-10 code for intraoperative circulatory system complication?
- I97.88 — Other intraoperative complications of the circulatory system, not elsewhere classified.
What is the ICD-10 code for postprocedural circulatory system complication?
- I97.89 — Other postprocedural complications and disorders of the circulatory system, not elsewhere classified.
Is I99.8 billable?
- Yes. I99.8 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can I99.8 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict I99.8 as a principal diagnosis.
Is I99.8 a CC or MCC?
- No. I99.8 is neither a CC nor an MCC under MS-DRG v44.0.