🧬 ICD-10 CM H05.242 — Constant Exophthalmos, Left Eye
Billable Code Confirmed
ICD-10 CM H05.242 is a fully specified, 6-character billable code that captures both the type of exophthalmos (constant, as opposed to intermittent or pulsating) and the affected side (left eye), meeting ICD-10-CM’s requirement for maximum specificity before a code can be reported for reimbursement.
Non-Billable Parent Codes
H05.24 “Constant exophthalmos” is not billable because it lacks the required laterality character. H05.2 “Exophthalmic conditions” is not billable because it lacks both the exophthalmos-type character and laterality character. H05 “Disorders of orbit” is not billable because it is a category-level header with no specificity at all.
Clinical Context
The distinction between constant, intermittent, and pulsating exophthalmos in the H05.24/H05.25/H05.26 series drives code selection based on the clinical pattern documented — constant exophthalmos reflects a fixed, persistent forward displacement of the globe (most classically from thyroid eye disease/Graves’ orbitopathy or an orbital space-occupying process), while intermittent or pulsating patterns point toward positional venous congestion or a vascular etiology such as a carotid-cavernous fistula, respectively.
Code Classification
This is a diagnosis code (ICD-10-CM), not a procedure code; it documents a clinical finding/sign and does not itself describe any treatment, imaging, or surgical intervention.
🔍 Code Description
ICD-10 CM H05.242 describes a persistent, non-fluctuating forward protrusion of the left globe beyond the normal orbital margin, most commonly encountered in the setting of thyroid eye disease (Graves’ orbitopathy), where autoimmune inflammation and glycosaminoglycan deposition expand the extraocular muscles and orbital fat within a fixed bony orbit. Other recognized causes of constant unilateral exophthalmos include an orbital mass or tumor, orbital cellulitis or abscess, orbital hemorrhage that has become chronic, and idiopathic orbital inflammatory disease (orbital pseudotumor); the “constant” descriptor specifically differentiates this presentation from the positional/intermittent pattern seen with orbital varices.
Clinically, this code is frequently paired with the underlying endocrine diagnosis when thyroid eye disease is the cause, and with orbital imaging codes to document and quantify the degree of proptosis. It is distinguished from H05.243 (bilateral constant exophthalmos), which is used when both orbits are symmetrically or asymmetrically but persistently affected, and from H05.251/H05.252 (intermittent exophthalmos), which is reserved for cases where globe protrusion varies with position**, Valsalva maneuver, or vascular congestion** rather than remaining fixed.
🌳 Code Tree / Hierarchy
H05.2 Exophthalmic conditions ❌ Non-billable
│
├── H05.20 Unspecified exophthalmos ✅ Billable
├── H05.21 Displacement (lateral) of globe ❌ Non-billable
│ │
│ ├── H05.211 Lateral displacement of globe, right eye ✅ Billable
│ └── H05.212 Lateral displacement of globe, left eye ✅ Billable
│
├── H05.24 Constant exophthalmos ❌ Non-billable
│ │
│ ├── H05.241 Constant exophthalmos, right eye ✅ Billable
│ ├── H05.242 Constant exophthalmos, left eye ◀ THIS CODE ✅ Billable
│ ├── H05.243 Constant exophthalmos, bilateral ✅ Billable
│ └── H05.249 Constant exophthalmos, unspecified eye ✅ Billable
│
└── H05.25 Intermittent exophthalmos ❌ Non-billable
│
├── H05.251 Intermittent exophthalmos, right eye ✅ Billable
└── H05.252 Intermittent exophthalmos, left eye ✅ BillableConstant vs. Unspecified Exophthalmos
Selecting H05.242 over the less-specific H05.20 (unspecified exophthalmos) requires the provider to have documented the pattern as “constant” or “persistent” rather than simply “exophthalmos” — auditors frequently downcode H05.24x claims to H05.20 when documentation does not explicitly support the constant/persistent qualifier.
Tip
When exophthalmos is attributable to Graves’ disease/thyrotoxicosis, most payers and ICD-10-CM guidelines favor sequencing the endocrine code (E05.-) first with H05.242 as a secondary manifestation code, since the thyroid disorder is the underlying etiology driving the orbital finding.
✅ Includes
- Persistent, non-positional forward protrusion of the left globe, however documented (e.g., “left proptosis,” “left eye bulging”).
- Constant left exophthalmos identified on clinical exam, exophthalmometry measurement, or orbital imaging, regardless of underlying cause.
- Use as either a principal diagnosis (e.g., admission specifically for orbital decompression) or a secondary/manifestation diagnosis when linked to an underlying systemic condition such as Graves’ disease.
❌ Excludes
Excludes 1
Q10.7 — Congenital malformation of orbit is excluded at the H05 category level and applies to all subcodes including H05.242, since congenital orbital malformations represent a structurally distinct, developmental condition rather than an acquired exophthalmic process.
Danger
A common Excludes1 error is reporting H05.242 alongside a congenital orbital malformation code for the same globe when the documentation actually describes a single congenital process; confirm whether the exophthalmos is acquired (supports H05.242) versus a feature of a documented congenital anomaly (supports Q10.7 instead) before finalizing code selection.
Excludes 2
No Excludes2 note is published for H05.242 or its H05.2 parent category, meaning there are no formally designated “not included here” conditions that require special handling with this code.
📋 Clinical Overview
Constant vs. Intermittent vs. Pulsating Exophthalmos
The H05.2x block separates exophthalmos into three clinically distinct patterns, and correctly identifying which applies is essential for both accurate coding and appropriate diagnostic workup, since each pattern points toward a different differential diagnosis.
| Feature | H05.242 | Related H05.252 | Related H05.262 |
|---|---|---|---|
| Pattern | Fixed, persistent globe protrusion present at all times and positions. | Globe protrusion that varies with position (e.g., bending forward) or Valsalva maneuver. | Globe protrusion that is synchronous with the patient’s pulse/heartbeat. |
| Typical Etiology | Thyroid eye disease, orbital mass, chronic orbital hemorrhage, orbital pseudotumor. | Orbital varix or other venous malformation causing position-dependent congestion. | Carotid-cavernous fistula or other vascular communication transmitting arterial pulsation into the orbit. |
| Workup Emphasis | Thyroid function testing, orbital CT/MRI, exophthalmometry trend over time. | Positional exophthalmometry, orbital venous imaging. | Auscultation for orbital bruit, CT/MR angiography of the orbit and cavernous sinus. |
Important
A CDI query is warranted whenever documentation simply states “exophthalmos” or “proptosis” without specifying constant, intermittent, or pulsating pattern, since defaulting to the unspecified code (H05.20-) understates the clinical picture and may not adequately support medical necessity for advanced imaging or surgical intervention.
Manifestations & Symptom Burden
- Visible forward displacement of the left globe, often first noted by the patient or a family member.
- Exposure keratopathy from incomplete lid closure over the protruding globe.
- Diplopia from extraocular muscle restriction, particularly common when the underlying cause is thyroid eye disease.
- Compressive optic neuropathy in severe cases, representing a vision-threatening complication that changes the urgency of surgical decompression.
Tip
Code any documented complication (exposure keratopathy, diplopia, optic neuropathy) as a separate, additional diagnosis rather than assuming it is implied by H05.242 alone, since ICD-10-CM does not bundle these manifestations into the exophthalmos code itself.
💰 HCC Risk Adjustment
ICD-10 CM H05.242 is not currently mapped to a CMS-HCC V28 category — flag this determination for direct verification against the live CMS-HCC V28 model files before finalizing any risk-adjustment abstraction, since isolated eye-finding codes are generally excluded from the model. If the underlying cause is Graves’ disease/thyrotoxicosis, ensure the corresponding E05.- endocrine code is also captured, since that code — not the exophthalmos manifestation itself — is more likely to carry HCC weight; verify the specific E05.- subcode’s HCC status independently as well.
🏥 MS-DRG Assignment
| DRG | Title | CC/MCC Status |
|---|---|---|
| 124 | Other Disorders of the Eye | With MCC |
| 125 | Other Disorders of the Eye | Without MCC |
ICD-10 CM H05.242 groups to MDC 02 “Diseases & Disorders of the Eye,” landing in DRG 124 or 125 depending on whether a qualifying MCC is present among the secondary diagnoses on the claim; there is no separate “with CC” tier for this MDC grouping, so sequencing accuracy of secondary diagnoses (e.g., compressive optic neuropathy, corneal ulceration from exposure) is what typically drives the MCC split. NCD/LCD note: no National Coverage Determination or Local Coverage Determination specific to the diagnosis code H05.242 itself was identified. However, when exophthalmos is due to thyroid eye disease and teprotumumab (Tepezza) infusion or bony orbital decompression (CPT 67414/67445) is being considered, coverage is governed by MAC-specific Local Coverage Articles/medical-necessity criteria for the associated drug/procedure codes rather than by the diagnosis code alone — flag for direct verification against your local MAC’s current coverage articles before billing associated services.
🔗 Related ICD-10-CM Codes
Same-Category Laterality/Pattern Variants
- H05.241 — Constant exophthalmos, right eye
- H05.243 — Constant exophthalmos, bilateral
- H05.249 — Constant exophthalmos, unspecified eye
- H05.252 — Intermittent exophthalmos, left eye
- H05.262 — Pulsating exophthalmos, left eye
- H05.212 — Lateral displacement of globe, left eye
Common Underlying Etiology Codes
- E05.00 — Thyrotoxicosis with diffuse goiter, without thyrotoxic crisis or storm
- E05.01 — Thyrotoxicosis with diffuse goiter, with thyrotoxic crisis or storm
- H06.221 — Graves’ ophthalmopathy, right eye
- H06.222 — Graves’ ophthalmopathy, left eye
- H05.312 — Atrophy of left orbit
🛠️ Commonly Associated CPT Codes
- 92060 — Sensorimotor examination with multiple measurements of ocular deviation; used to quantify diplopia associated with exophthalmos-related muscle restriction.
- 76512 — Ophthalmic ultrasound, B-scan; often used to assess orbital soft tissue and optic nerve involvement.
- 70480 — CT orbit, without contrast; a primary imaging study to characterize the degree and etiology of proptosis.
- 70540 — MRI orbit, face, and/or neck, without contrast; frequently used to evaluate extraocular muscle enlargement in thyroid eye disease.
- 67414 — Orbitotomy with removal of bone for decompression; a definitive surgical treatment for disfiguring or vision-threatening exophthalmos.
- 67445 — Orbitotomy with bone removal, lateral approach, for decompression; an alternative surgical approach to bony orbital decompression.
- 92081 — Visual field examination, limited; used to screen for compressive optic neuropathy in severe cases.
🏷️ Modifier Reference
| Modifier | Name | When to Apply |
|---|---|---|
| -LT | Left Side | Append to any associated CPT procedure or imaging code performed on the left orbit to confirm laterality concordance with the H05.242 diagnosis. |
| -59 | Distinct Service | Apply when a left-orbit procedure is billed alongside a separate, distinct right-orbit or unrelated procedure on the same date to avoid inappropriate bundling. |
| -25 | Significant E/M | Apply when a significant, separately identifiable E/M service is performed on the same day as a minor procedure related to this diagnosis (e.g., exophthalmometry measurement plus a same-day office visit). |
| -76 | Repeat Procedure, Same Physician | Apply when a diagnostic test (e.g., orbital ultrasound) is repeated by the same physician to trend disease progression. |
NCCI Bundling Considerations
As a diagnosis code, H05.242 itself is not subject to NCCI procedure-to-procedure edits; however, when reporting associated CPT imaging or surgical codes supported by this diagnosis, verify that orbital CT/MRI and ultrasound are not billed together for the same encounter without medical-necessity documentation for both, and that the professional and technical components of imaging studies are split appropriately per your facility’s billing arrangement.
🔬 ICD-10-PCS Crosswalk
Caution
ICD-10-PCS codes apply only to inpatient hospital procedures, not to diagnosis codes; H05.242 itself has no direct PCS equivalent. The codes below represent the PCS procedures most commonly performed to treat the underlying exophthalmos when a patient is admitted as an inpatient — flag each for verification against your encoder before use.
| PCS Code | Description | Notes |
|---|---|---|
0N583ZZ | Destruction of Left Orbit, Percutaneous Approach | Represents ablative/destructive treatment of orbital tissue; verify against operative documentation and encoder logic before use. |
0NB3ZZ (incomplete — verify full 7-character code) | Excision, Left Orbital Bone | Represents partial bone excision for decompression; confirm approach and qualifier characters against the operative note. |
0N983ZZ | Release of Left Orbit, Percutaneous Approach | Reflects release of compressive tissue/adhesions around the orbit; verify root operation selection (Release vs. Excision) based on the surgeon’s documented technique. |
💊 Coding Scenarios and Examples
Example 1
Clinical Scenario:
A 44-year-old female with a known history of Graves’ disease presents with progressively worsening protrusion of the left eye over the past four months, confirmed on exophthalmometry to be persistent and non-positional. She is admitted for planned left orbital decompression surgery.
| Field | Code | Rationale |
|---|---|---|
| CPT | 67414--LT | Orbitotomy with bone removal for decompression, left side, matching the documented surgical intervention. |
| PDx | E05.00 | Thyrotoxicosis with diffuse goiter is the underlying etiology driving the orbital finding and the reason for admission. |
| Sec Dx | H05.242 | Constant exophthalmos, left eye, captures the specific orbital manifestation being surgically treated. |
Tip
Sequence the endocrine diagnosis first when it is clearly documented as the causal condition; H05.242 is reported as a manifestation/secondary diagnosis in this scenario, not the principal diagnosis, since guidelines favor coding the underlying systemic disease first when a clear cause-and-effect relationship is documented.
Example 2
Clinical Scenario:
A 52-year-old male presents with new-onset constant left eye bulging without any known thyroid history. Orbital MRI reveals a left orbital mass. He undergoes MRI orbit imaging and a subsequent biopsy is scheduled as a separate encounter.
| Field | Code | Rationale |
|---|---|---|
| CPT | 70540 | MRI orbit without contrast, performed to characterize the newly identified orbital mass and quantify the degree of proptosis. |
| CPT 2 | 92060 | Sensorimotor examination performed to assess for associated ocular motility restriction from the mass effect. |
| PDx | H05.242 | Constant exophthalmos, left eye, is reported as the principal diagnosis for this encounter since the underlying orbital mass has not yet been histologically confirmed. |
Tip
Because the etiology (tumor type) is not yet established at this encounter, H05.242 is appropriately sequenced as principal diagnosis rather than a presumed neoplasm code; update the diagnosis once pathology results are available.
Example 3
Clinical Scenario:
A 38-year-old female with thyroid eye disease returns for a follow-up visit to trend her left-sided proptosis, which has remained clinically stable and constant since her last visit three months ago. Repeat exophthalmometry and ultrasound are performed in the office.
| Field | Code | Rationale |
|---|---|---|
| CPT | 76512--76 | Repeat ophthalmic B-scan ultrasound by the same physician to trend disease stability over time. |
| PDx | H05.242 | Constant exophthalmos, left eye, remains the appropriate diagnosis for this stable, ongoing finding. |
Tip
For stable, chronic findings being monitored rather than actively treated, ensure documentation explicitly states “stable” or “unchanged” to support medical necessity for repeat imaging rather than triggering a denial for lack of clinical change.
⚠️ Coding Pitfalls and Tips
- Pitfall 1: Defaulting to unspecified exophthalmos (H05.20-) when documentation actually supports a specific pattern (constant, intermittent, or pulsating); Tips: Query the provider whenever “exophthalmos” or “proptosis” is documented without a pattern descriptor.
- Pitfall 2: Failing to sequence the underlying endocrine diagnosis (E05.-) first when Graves’ disease is the documented cause; Tips: Review the H&P and endocrinology notes for a thyroid diagnosis before finalizing H05.242 as principal.
- Pitfall 3: Reporting H05.242 alongside a congenital orbital malformation code (Q10.7) for the same eye without clarifying whether the process is acquired or congenital; Tips: Confirm the Excludes1 relationship and select only the code that matches the documented etiology.
- Pitfall 4: Assigning laterality codes based on assumption rather than explicit documentation; Tips: Never infer “left” from context alone — confirm the specific eye is stated in the note before finalizing H05.242 over H05.241/H05.243/H05.249.
- Pitfall 5: Omitting associated complications (exposure keratopathy, compressive optic neuropathy, diplopia) as separate codes; Tips: Review the full assessment/plan for each visit, since these manifestations are not bundled into H05.242 and materially affect severity and MCC status.
- Pitfall 6: Assuming a Medicare NCD/LCD governs the diagnosis code itself; Tips: Remember that coverage determinations attach to the associated CPT/HCPCS service (imaging, teprotumumab infusion, orbital decompression), not to the ICD-10-CM diagnosis code — verify local MAC policy for the specific service being billed.
📚 Sources
1. Centers for Disease Control and Prevention, National Center for Health Statistics. *ICD-10-CM FY2026 Code Tables and Index.* CDC/NCHS; 2025-2026. https://www.cms.gov/medicare/coding-billing/icd-10-codes 2. ICD10Data.com. *2026 ICD-10-CM Diagnosis Code H05.242 — Constant Exophthalmos, Left Eye.* 2026. https://www.icd10data.com/ICD10CM/Codes/H00-H59/H00-H05/H05-/H05.242 3. AAPC. *ICD-10-CM Code for Exophthalmic Conditions H05.2 and Constant Exophthalmos H05.24.* Codify by AAPC; 2026. https://www.aapc.com/codes/icd-10-codes/H05.2 4. Centers for Medicare & Medicaid Services. *MS-DRG Definitions Manual, Version 43.0.* CMS; 2026. 5. UnitedHealthcare. *Tepezza (Teprotumumab-trbw) Medical Policy.* UHC; 2026. https://www.uhcprovider.com/content/dam/provider/docs/public/policies/comm-medical-drug/tepezza.pdf 6. AAPC. *CPT Code 67414 — Orbitotomy with Removal of Bone for Decompression.* Codify by AAPC; 2026. https://www.aapc.com/codes/cpt-codes/67414Sources listed above correspond to superscript citations throughout this note. Verify all Medicare payment figures against your current CMS PFS Lookup tool and applicable MAC LCD prior to claim submission. Please use the latest AAPC/AHIMA Coding Books to verify each code within this note.