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Key takeaways
- Glaucoma codes sit in H40, and most open-angle, angle-closure and secondary types need a 7th character stage.
- The stage values are 0 unspecified, 1 mild, 2 moderate, 3 severe and 4 indeterminate.
- Primary open-angle glaucoma uses H40.111- for the right eye, H40.112- for the left and H40.113- for both.
- When the eyes have a different type or stage, each eye gets its own code.
What Is the ICD-10 Code for Glaucoma?
Glaucoma is coded in ICD-10-CM category H40, where each code names the glaucoma type, the eye and, for most types, the stage. H40.9, unspecified glaucoma, exists but rarely supports a test or procedure.
H40 sits in chapter 7, the eye chapter, alongside the other codes in the ophthalmology ICD-10 codes list. Glaucoma in a disease classified elsewhere uses H42, and congenital glaucoma uses Q15.0.
How Is a Glaucoma Code Built?
A staged glaucoma code is built in 3 parts, which are the type in the first 5 characters, the eye in the 6th and the stage in the 7th. The table breaks down H40.1132.
| Part of the code | Characters | Example H40.1132 |
|---|---|---|
| Type | H40.11 for primary open-angle | Primary open-angle glaucoma |
| Eye | 1 right, 2 left, 3 bilateral, 9 unspecified | 3, both eyes |
| Stage | 0 to 4 | 2, moderate stage |
Older references show H40.11X1, which was replaced in 2016 when the eye character was added. A code without its 7th character rejects.
What Are the Glaucoma Stage Characters?
The 7th character stages are 0 unspecified, 1 mild, 2 moderate, 3 severe and 4 indeterminate, based on optic nerve and visual field findings. The table gives the usual clinical meaning of each stage.
| 7th character | Stage | Usual findings |
|---|---|---|
| 0 | Unspecified | The stage is not documented |
| 1 | Mild | Optic nerve changes with a normal visual field |
| 2 | Moderate | Field loss in one hemifield, not within 5 degrees of fixation |
| 3 | Severe | Field loss in both hemifields, or within 5 degrees of fixation |
| 4 | Indeterminate | The stage cannot be determined, such as an unreliable field |
Stage 0 and stage 4 are not the same. Stage 0 means nobody recorded the stage, while stage 4 means the provider tried and could not determine it.
Which Glaucoma Types Have Their Own Codes?
H40 splits glaucoma into suspects, open-angle types, angle-closure types and secondary types, and each has its own code family. The table lists the families eye practices use most, with a right eye example.
| Type | Code family | Stage needed | Right eye example |
|---|---|---|---|
| Open angle, borderline findings, low risk | H40.01- | No | H40.011 |
| Open angle, borderline findings, high risk | H40.02- | No | H40.021 |
| Ocular hypertension | H40.05- | No | H40.051 |
| Primary angle closure without glaucoma damage | H40.06- | No | H40.061 |
| Primary open-angle glaucoma | H40.11- | Yes | H40.1112, moderate |
| Low-tension glaucoma | H40.12- | Yes | H40.1211, mild |
| Pigmentary glaucoma | H40.13- | Yes | H40.1312, moderate |
| Pseudoexfoliation (capsular) glaucoma | H40.14- | Yes | H40.1413, severe |
| Acute angle-closure attack | H40.21- | No | H40.211 |
| Chronic angle-closure glaucoma | H40.22- | Yes | H40.2212, moderate |
| Glaucoma secondary to drugs | H40.6- | Yes | H40.61X1, mild |
Secondary glaucoma from trauma (H40.3-), inflammation (H40.4-) and other eye disorders (H40.5-) also take a stage, and the cause should be coded as well.
How Do You Code Glaucoma in Both Eyes?
Use the bilateral code when both eyes have the same type and the same stage, and code each eye separately when the type or stage differs. The official ICD-10-CM guidelines for chapter 7 set these rules.
| Findings | Codes |
|---|---|
| POAG, moderate stage, both eyes | H40.1132 |
| POAG, mild right eye, severe left eye | H40.1111 and H40.1123 |
| POAG right eye, pseudoexfoliation glaucoma left eye, both mild | H40.1111 and H40.1421 |
For codes with no eye character, such as unspecified open-angle glaucoma (H40.10X-), report one code for each type with its stage.
What if the stage changes?
The stage on each claim follows that visit's findings. A patient whose field worsens from mild to moderate moves from 1 to 2 at the visit where the change is documented.
Which Procedures Do Glaucoma Codes Support?
Glaucoma codes support optic nerve OCT, visual fields, gonioscopy, laser and surgery, and each service has its own covered diagnosis list. The table pairs common glaucoma services with their CPT codes.
| Service | CPT code |
|---|---|
| Optic nerve OCT | 92133 |
| Visual field, extended | 92083 |
| Gonioscopy | 92020 |
| Laser trabeculoplasty | 65855 |
| Trabeculectomy | 66170 |
| Cataract surgery with a glaucoma drainage device | 66989, 66991 |
Suspect codes support testing but not glaucoma surgery. Our glaucoma billing services team matches each test and procedure to a covered code.
Why Do Glaucoma Claims Deny?
Glaucoma claims deny most often because the code is missing its stage, uses the old H40.11X- format or names an eye that does not match the procedure. These checks prevent most of them.
- Full code. Staged types have 7 characters.
- Current format. POAG uses H40.111- to H40.119-, not H40.11X-.
- Real stage. Avoid stage 0 when the field results are in the record.
- Matching eye. The eye in the code matches RT or LT on the procedure.
Our ophthalmology medical coding services check every glaucoma code against the exam and test results before the claim is sent.