H40.033

Here is a detailed guide note for H40.033, formatted as clean text for your reference.

🧬 ICD-10-CM H40.033 - Anatomical narrow angle, bilateral**

Description

• Definition: This code describes a patient with anatomically narrow anterior chamber angles in both eyes. It is often clinically referred to as “Primary Angle Closure Suspect” (PACS).
• Clinical Context: The patient has not yet developed glaucomatous optic neuropathy or high intraocular pressure (IOP), but the anatomy puts them at risk for angle-closure glaucoma.
• Laterality: This specific code is for Bilateral involvement.
  • Right Eye only: H40.031
  • Left Eye only: H40.032

Body area

• Eye—anterior chamber angle/iridocorneal angle; laterality: both eyes.​​

Includes / Excludes

• Includes: ICD-10-CM tabular labels H40.03 “Anatomical narrow angle” as “Primary angle closure suspect.”​

• Excludes1: At the H40 “Glaucoma” category level, Excludes1 includes absolute glaucoma (H44.51-), congenital glaucoma (Q15.0), and traumatic glaucoma due to birth injury (P15.3).​​

• Excludes2: Not shown for H40.03/H40.033 in the available excerpt.

Risk Adjustment (HCC) Status

• HCC Weight: No.
• Clinical Note: “Suspect” codes and anatomical findings generally do not map to a Hierarchical Condition Category (HCC). Only established glaucoma with damage (e.g., Primary Angle-Closure Glaucoma H40.2-) typically carries a risk score.

Common Associated CPT Codes

1. Diagnostic Imaging

• 76512: Ophthalmic Ultrasound, diagnostic; Anterior Segment (UBM).
  • Medical Necessity: This is the “gold standard” for imaging the angle, ciliary body, and iris to confirm narrow angles or rule out plateau iris syndrome.
  • Coding Tip: If performing UBM, you must use immersion techniques. Do not confuse this with a standard B-Scan (76512) used for the retina.
• 92132: Scanning Computerized Ophthalmic Diagnostic Imaging, Anterior Segment (AS-OCT).
  • Usage: Used to measure the angle opening distance (AOD) and document the narrow angle non-invasively.

2. Surgical Intervention (Prophylactic)

• 66761: iridotomy/Iridectomy by laser surgery (e.g., YAG PI).
  • Usage: This is the standard prophylactic treatment to prevent acute angle closure.
  • Global Period: 10 Days.
• 66984 / 66982: Cataract Extraction.
  • Usage: Cataract surgery is often performed to deepen the anterior chamber and resolve the narrow angle (Lens-based glaucoma management).

Compliance & Audit Alerts

• Medical Necessity for Imaging: If billing 76513 (UBM), documentation must specifically describe the anterior segment structures (angle, iris, ciliary body). If you image the retina/optic nerve, you must bill 76512 instead. You typically cannot bill both on the same eye.
• Prophylactic vs. Therapeutic: Since H40.033 is an anatomical finding (risk factor) rather than active disease, ensure your chart notes justify the need for surgery (e.g., “Patient has narrow angles with 180 degrees of appositional closure, risking acute occlusion”).
• Differentiation: Do not use this code if the patient has established Primary Angle-Closure Glaucoma (optic nerve damage or PAS). Use the H40.22- series for chronic angle closure.

Common modifiers (CPT)

Modifier	Meaning (high-level)	Common ophtho use
-25	Significant, separately identifiable E/M	E/M with same-day testing/procedure
-RT	Right side	Procedure laterality
-LT	Left side	Procedure laterality
-50	Bilateral procedure	When the procedure is performed bilaterally
-59	Distinct procedural service	When appropriate to show distinctness
-24	Unrelated E/M in postop period	Global period situations

Common CPTs used with this diagnosis (examples)

• 92004 / 92014 or 99202-99205 / 99212-99215 (evaluation/management depending on documentation).​

• 92083 (visual field exam, extended).​

• 92133 (scanning computerized ophthalmic diagnostic imaging—optic nerve, e.g., OCT RNFL), often supported for glaucoma/glaucoma suspect workups; CMS lists H40.033 among covered diagnoses in related billing/coding articles.

• 76514 (corneal pachymetry) may be used in glaucoma risk assessment contexts when medically necessary.​

Example coding

Example: ophthalmologist documents “primary angle closure suspect OU” (narrow angles both eyes) → code H40.033.