H49.819
BillableKearns-Sayre syndrome, unspecified eye
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is H49.819 an HCC code?
Yes. H49.819 maps to Other Significant Endocrine and Metabolic Disorders under the V24 model but is not retained in V28.
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 H49.819
For H49.819to 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 H49.819 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
H49.819 is the ICD-10-CM diagnosis code for kearns-sayre syndrome, unspecified eye. Kearns-Sayre syndrome is a rare inherited mitochondrial disorder affecting the muscles that control eye movement, causing progressive weakness and eye misalignment. H49.819 sits in the ICD-10-CM chapter for diseases of the eye and adnexa (h00-h59), within the section covering disorders of ocular muscles, binocular movement, accommodation and refraction (h49-h52).
Under the older CMS-HCC V24 model, H49.819 maps to Other Significant Endocrine and Metabolic Disorders (HCC 23) with a community, non-dual, aged base RAF weight of 0.230. 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.
This code is specific to Kearns-Sayre syndrome; verify the diagnosis is documented before coding. Because H49.819 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 H49.819 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code is specific to Kearns-Sayre syndrome; verify the diagnosis is documented before coding
- •Kearns-Sayre is a systemic condition - check for documentation of cardiac conduction defects or other associated manifestations
Clinical Significance
Kearns-Sayre syndrome is a rare mitochondrial myopathy characterized by progressive external ophthalmoplegia and pigmentary retinopathy, with onset before age 20. It can also involve cardiac conduction defects, cerebellar ataxia, and elevated cerebrospinal fluid protein. This is a multisystem disease with significant morbidity that warrants comprehensive risk adjustment capture given the complex, lifelong care needs.
Documentation Requirements
- ✓Laterality clearly specified as unspecified eye for the ocular manifestation
- ✓Documented diagnosis of Kearns-Sayre syndrome by a qualified provider
- ✓Evidence of progressive external ophthalmoplegia (ptosis, limited eye movement)
- ✓Evidence of pigmentary retinopathy on fundoscopic examination
- ✓Age of onset documented (typically before age 20)
- ✓Genetic testing or muscle biopsy results confirming mitochondrial DNA deletion if available
- ✓Cardiac evaluation results (ECG for conduction defects)
- ✓Documentation of any additional systemic manifestations (ataxia, hearing loss, endocrine dysfunction)
Commonly Confused Codes
- •H49.00-H49.03 — Third nerve palsy (isolated cranial nerve palsy, not progressive mitochondrial disease)
- •H49.10-H49.13 — Fourth nerve palsy (isolated palsy without systemic features)
- •H49.20-H49.23 — Sixth nerve palsy (isolated palsy without systemic features)
- •H49.881-H49.889 — Other paralytic strabismus (non-specific; use Kearns-Sayre code when syndrome is diagnosed)
- •G71.0 — Muscular dystrophy (different category of myopathy; Kearns-Sayre is mitochondrial)
- •H51.9 — Unspecified disorder of binocular movement (non-specific code that misses the underlying syndrome)