H42
BillableGlaucoma in diseases classified elsewhere
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is H42 an HCC code?
No. H42 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
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 H42
For H42to 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 H42 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
H42 is the ICD-10-CM diagnosis code for glaucoma in diseases classified elsewhere. Glaucoma that develops as a result of another disease or condition affecting the eye. H42 sits in the ICD-10-CM chapter for diseases of the eye and adnexa (h00-h59), within the section covering glaucoma (h40-h42).
H42 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
Maps to RxHCC 244 (Glaucoma, Other) with a RAF weight of 0.000 in the prescription drug model. No mapping under CMS-HCC v28, v24, or ESRD models. The underlying systemic disease may carry its own HCC mapping, so ensure the primary condition is also coded for complete risk adjustment capture. No hierarchies apply for H42 itself.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for H42 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code requires a secondary diagnosis code for the underlying disease causing the glaucoma
- •Common underlying conditions include diabetes, inflammation, or vascular disorders; ensure both conditions are coded
Clinical Significance
This manifestation code identifies glaucoma occurring secondary to systemic or other classified diseases, such as diabetes mellitus, amyloidosis, Lowe syndrome, or other metabolic disorders. As a manifestation code, H42 must always be sequenced after the underlying disease code. Capturing this relationship is important for understanding the full clinical picture and comorbidity burden of the patient.
Documentation Requirements
- ✓Documented diagnosis of glaucoma as a manifestation of an underlying systemic disease
- ✓Identification and documentation of the underlying disease (e.g., diabetes, amyloidosis, Lowe syndrome)
- ✓Confirmation that glaucoma is causally related to the underlying condition
- ✓Intraocular pressure measurement
- ✓Optic nerve evaluation
- ✓Code the underlying disease first, then H42 as the manifestation code
Excludes 1 — Do NOT code together
Code First
Commonly Confused Codes
- •H40.40-H40.43 — Glaucoma secondary to eye inflammation (use for uveitic glaucoma, not systemic disease)
- •H40.50-H40.53 — Glaucoma secondary to other eye diseases (use for other ocular conditions causing glaucoma)
- •H40.60-H40.63 — Glaucoma secondary to drugs (use when medication is the cause)
- •H40.89 — Other specified glaucoma (use when glaucoma type is specified but not secondary to a classified disease)
- •E11.39 — Type 2 diabetes with other diabetic ophthalmic complication (the underlying code that would pair with H42)