2026 ICD-10-CM Diagnosis Code I99.8Other disorder of circulatory system

ICD-10-CM Codes›I00–I99›I95-I99›I99

ICD-10-CM I99.8
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I99.8 is a billable ICD-10-CM diagnosis code for other disorder of circulatory system. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 302 through 303. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified circulatory disease.

Code Identity

ICD-10-CM Code
I99.8
Billable Status
Yes — Valid for Submission
Code Describes
Other disorder of circulatory system
Short Description
Other disorder of circulatory system
Same as the full description in the CMS dataset.
Parent Code
I99
Other and unspecified disorders of circulatory system

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI95-I99Other and unspecified disorders of the circulatory system
CategoryI99Other and unspecified disorders of circulatory system
This CodeI99.8Other disorder of circulatory system

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abnormality of hepatic vein
  • Acquired arteriovenous malformation
  • Acquired arteriovenous malformation of vascular structure of gastrointestinal tract
  • Acute ischemic pancreatitis
  • Acute lower limb ischemia
  • Acute vascular insufficiency
  • Acute visceral ischemia
  • Alteration in tissue perfusion
  • Arterial ischemia
  • Arteriovenous fistula occlusion
  • Arteriovenous fistula rupture
  • Arteriovenous graft occlusion
  • Arteriovenous shunt occlusion
  • Bacterial cardiovascular infection
  • Brown-Séquard syndrome due to ischemia
  • Calcinosis following arterial/venous infarct
  • Cardiovascular fistula due to endocarditis
  • Cardiovascular morbidity
  • Cardiovascular system hereditary disorder
  • Chronic disease of cardiovascular system
  • Chronic vascular insufficiency
  • Complement hyperactivation, angiopathic thrombosis, protein losing enteropathy syndrome
  • Contusion of skin due to vascular fragility
  • Critical ischemia of foot
  • Critical lower limb ischemia
  • Cushing phenomenon
  • Decay accelerating factor deficiency
  • Dehiscence of aortic valve annulus as complication of procedure
  • Dermatosis resulting from small vessel insufficiency
  • Dilated blood vessels in skin
  • Disorder of arteriovenous shunt
  • Disorder of oxygen transport
  • Disorder of portal venous system
  • Disruption of aortic valve annulus
  • Ductus arteriosus dependent systemic circulation
  • Entrapment of blood vessel
  • Flap ischemia
  • Fragile blood vessel
  • Fungal cardiovascular infection
  • Gaucher disease with ophthalmoplegia and cardiovascular calcification
  • Gaucher's disease
  • Graft failure due to prolonged ischemia
  • Hereditary cutaneous vascular syndrome
  • Hereditary dysplasia of blood vessel
  • Hypostasis
  • Impairment of peripheral tissue perfusion
  • Inadequate flow to support prescribed dialysis blood flow
  • Increased capillary fragility
  • Ineffective tissue perfusion
  • Ischemia
  • Ischemia of bilateral lower limbs
  • Ischemia of bilateral upper limbs
  • Ischemia of left lower extremity
  • Ischemia of left upper limb
  • Ischemia of right lower extremity
  • Ischemia of right upper limb
  • Ischemia of stoma
  • Ischemic anterior cord syndrome
  • Ischemic finger
  • Ischemic foot
  • Ischemic hand
  • Ischemic pancreatitis
  • Ischemic reperfusion injury
  • Ischemic toe
  • Limb ischemia
  • Lower limb ischemia
  • Mass of cardiovascular structure
  • Obstruction of surgically constructed systemic venous pathway as complication of procedure
  • Occlusion of microvasculature of skin caused by platelet plug
  • Pain of bilateral lower limbs co-occurrent and due to ischemia
  • Pain of bilateral upper limbs co-occurrent and due to ischemia
  • Pain of left lower limb co-occurrent and due to ischemia
  • Pain of left upper limb co-occurrent and due to ischemia
  • Pain of right lower limb co-occurrent and due to ischemia
  • Peripheral ischemia
  • Protein-losing enteropathy
  • Purpura due to increased intravascular pressure
  • Retinal arteriovenous dilatation
  • Right upper limb pain co-occurrent and due to ischemia
  • Subacute neuronopathic Gaucher's disease
  • Thrombophilia due to vascular anomaly
  • Transient ischemia
  • Upper limb ischemia
  • Vascular calcification
  • Vascular graft calcification
  • Vascular graft occlusion
  • Vascular insufficiency
  • Venous collateral circulation
  • Viral cardiovascular infection
  • Visceral ischemia

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Angiectasis, angiectopia
    • Atrophy, atrophic(of)
      • vascular
    • Blood
      • pressure
        • fluctuating
    • Circulation
      • collateral, any site
    • Complication(s) (from) (of)
      • circulatory system
    • Congestion, congestive
      • circulatory NEC
    • Dilatation
      • blood vessel
    • Disease, diseased
      • circulatory (system) NEC
    • Disease, diseased
      • vascular
        • occlusive
    • Dissection
      • vascular
    • Fluctuating blood pressure
    • Insufficiency, insufficient
      • arteriovenous
    • Insufficiency, insufficient
      • circulatory NEC
    • Insufficiency, insufficient
      • vascular
    • Ischemia, ischemic
    • Obstruction, obstructed, obstructive
      • circulatory
    • Obstruction, obstructed, obstructive
      • vessel NEC
    • Occlusion, occluded
      • vascular NEC
    • Occlusion, occluded
      • vessel (blood)

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR CIR032
Other specified and unspecified circulatory disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Vascular Calcification

    deposition of calcium into the blood vessel structures. excessive calcification of the vessels is associated with atherosclerotic plaques formation particularly after myocardial infarction (see monckeberg medial calcific sclerosis) and chronic kidney diseases which in turn increase vascular stiffness.

  • Brain Ischemia

    localized reduction of blood flow to brain tissue due to arterial obstruction or systemic hypoperfusion. this frequently occurs in conjunction with brain hypoxia (hypoxia, brain). prolonged ischemia is associated with brain infarction.

  • Chronic Limb-Threatening Ischemia

    a severe form of peripheral artery disease in which a hypoperfusion of the blood through an organ or tissue is caused by occlusion of peripheral arterial vessels. it is associated with the presence of chronic ischemic rest pain, ulceration or gangrene.

  • Cold Ischemia

    the chilling of a tissue or organ during decreased blood perfusion or in the absence of blood supply. cold ischemia time during organ transplantation begins when the organ is cooled with a cold perfusion solution after organ procurement surgery, and ends after the tissue reaches physiological temperature during implantation procedures.

  • Hypoxia-Ischemia, Brain

    a disorder characterized by a reduction of oxygen in the blood combined with reduced blood flow (ischemia) to the brain from a localized obstruction of a cerebral artery or from systemic hypoperfusion. prolonged hypoxia-ischemia is associated with ischemic attack, transient; brain infarction; brain edema; coma; and other conditions.

  • Ischemia

    a hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation.

  • Ischemic Attack, Transient

    brief reversible episodes of focal, nonconvulsive ischemic dysfunction of the brain having a duration of less than 24 hours, and usually less than one hour, caused by transient thrombotic or embolic blood vessel occlusion or stenosis. events may be classified by arterial distribution, temporal pattern, or etiology (e.g., embolic vs. thrombotic). (from adams et al., principles of neurology, 6th ed, pp814-6)

  • Mesenteric Ischemia

    ischemic tissue injury produced by insufficient perfusion of intestinal tissue by the mesenteric circulation (i.e., celiac artery; superior mesenteric artery; infererior mesenteric artery; and mesenteric veins). it can progress from ischemia; edema; and gangrene of the bowel wall to peritonitis and cardiovascular collapse.

  • Myocardial Ischemia

    a disorder of cardiac function caused by insufficient blood flow to the muscle tissue of the heart. the decreased blood flow may be due to narrowing of the coronary arteries (coronary artery disease), to obstruction by a thrombus (coronary thrombosis), or less commonly, to diffuse narrowing of arterioles and other small vessels within the heart. severe interruption of the blood supply to the myocardial tissue may result in necrosis of cardiac muscle (myocardial infarction).

  • Optic Neuropathy, Ischemic

    ischemic injury to the optic nerve which usually affects the optic disk (optic neuropathy, anterior ischemic) and less frequently the retrobulbar portion of the nerve (optic neuropathy, posterior ischemic). the injury results from occlusion of arterial blood supply which may result from temporal arteritis; atherosclerosis; collagen diseases; embolism; diabetes mellitus; and other conditions. the disease primarily occurs in the sixth decade or later and presents with the sudden onset of painless and usually severe monocular visual loss. anterior ischemic optic neuropathy also features optic disk edema with microhemorrhages. the optic disk appears normal in posterior ischemic optic neuropathy. (glaser, neuro-ophthalmology, 2nd ed, p135)

  • Reperfusion Injury

    adverse functional, metabolic, or structural changes in tissues that result from the restoration of blood flow to the tissue (reperfusion) following ischemia.

  • Spinal Cord Ischemia

    reduced blood flow to the spinal cord which is supplied by the anterior spinal artery and the paired posterior spinal arteries. this condition may be associated with arteriosclerosis, trauma, emboli, diseases of the aorta, and other disorders. prolonged ischemia may lead to infarction of spinal cord tissue.

  • Vertebrobasilar Insufficiency

    localized or diffuse reduction in blood flow through the vertebrobasilar arterial system, which supplies the brain stem; cerebellum; occipital lobe; medial temporal lobe; and thalamus. characteristic clinical features include syncope; lightheadedness; visual disturbances; and vertigo. brain stem infarctions or other brain infarction may be associated.

  • Warm Ischemia

    a tissue or organ remaining at physiological temperature during decreased blood perfusion or in the absence of blood supply. during organ transplantation it begins when the organ reaches physiological temperature before the completion of surgical anastomosis and ends with reestablishment of the blood circulation through the tissue.

  • Vascular Calcification

    deposition of calcium in vascular structures.

Convert I99.8 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
459.89 Circulatory disease NEC
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About I99.8Overview

Is I99.8 (Other and unspecified disorders of circulatory system) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other disorder of circulatory system on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does I99.8 group to?

When other disorder of circulatory system is the principal diagnosis on an inpatient stay, it groups to MS-DRG 302, 303, with relative weights from 0.6732 to 1.1966 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of I99.8?

Under the General Equivalence Mappings, other disorder of circulatory system converts to ICD-9-CM 459.89 (circulatory disease NEC). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.