I60.10
BillableNontraumatic subarachnoid hemorrhage from unspecified middle cerebral artery
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is I60.10 an HCC code?
Yes. I60.10 maps to Intracranial Hemorrhage under the CMS-HCC V28 risk adjustment model (and Intracranial Hemorrhage under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for I60.10
For I60.10to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed I60.10 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
I60.10 is the ICD-10-CM diagnosis code for nontraumatic subarachnoid hemorrhage from unspecified middle cerebral artery. Bleeding in the space between the brain and its protective membrane (subarachnoid space) caused by a ruptured blood vessel in the middle cerebral artery, not due to trauma or injury. This is a serious medical emergency that requires immediate treatment. I60.10 sits in the ICD-10-CM chapter for diseases of the circulatory system (i00-i99), within the section covering cerebrovascular diseases (i60-i69).
Under the CMS-HCC V28 risk adjustment model, I60.10 maps to Intracranial Hemorrhage (HCC 248) with a community, non-dual, aged base RAF weight of 0.239. Under the older V24 model, I60.10 mapped to the same category but with a base RAF weight of 0.230 — V28 recalibrated weights across the entire model. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
Verify the specific artery location is truly unspecified; if documentation indicates left or right middle cerebral artery, use more specific codes I60.11 or I60.12 instead. Because I60.10 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for I60.10 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
Clinical Significance
Nontraumatic subarachnoid hemorrhage from unspecified middle cerebral artery is a severe cerebrovascular event. The middle cerebral artery is one of the most common locations for cerebral aneurysm rupture. These hemorrhages often cause significant neurological deficits affecting speech, motor function, and cognition. Laterality specification should always be pursued.
Documentation Requirements
- ✓Provider must document nontraumatic subarachnoid hemorrhage from the middle cerebral artery
- ✓Laterality should be specified — this code is used when side is not documented
- ✓Imaging confirmation of hemorrhage source
- ✓Underlying pathology: aneurysm at middle cerebral artery bifurcation or trifurcation
- ✓Neurological deficit assessment
- ✓Treatment approach: surgical clipping vs endovascular intervention
Commonly Confused Codes
- •I60.11 — Nontraumatic subarachnoid hemorrhage from right middle cerebral artery: lateralized to right
- •I60.12 — Nontraumatic subarachnoid hemorrhage from left middle cerebral artery: lateralized to left
- •I60.00 — Nontraumatic subarachnoid hemorrhage from unspecified carotid siphon: different arterial location
- •I61.0 — Nontraumatic intracerebral hemorrhage in hemisphere, subcortical: bleeding into brain tissue from middle cerebral artery territory
- •I60.7 — Nontraumatic subarachnoid hemorrhage from unspecified intracranial artery: even more nonspecific