H40.839 ICD-10-CM Code: Aqueous misdirection, unspecified eye
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Diseases of the eye and adnexa (H00-H59) / Glaucoma (H40-H42)
H40.839
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceAqueous misdirection, unspecified eye
A condition where fluid in the eye flows in the wrong direction, but the specific eye affected is not documented or specified.
Buddy Insight
Aqueous misdirection, also known as malignant glaucoma or ciliary block glaucoma, is a serious condition where aqueous humor is misdirected posteriorly into the vitreous cavity rather than flowing anteriorly through the pupil.
CMS-HCC V28
00
RAF 0
CMS-HCC V24
00
RAF 0
ACA/HHS
00
RAF 0
ESRD/PACE
00
RAF 0
RXHCC
MappedHCC 244
RAF 0.0
Code Trumping
Basket needed
Code Book Path
Inclusion Terms
Official- Malignant glaucoma
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for H40.839 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for H40.839 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for H40.839 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for H40.839 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for H40.839 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for H40.839 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is H40.839 an HCC code?
No. H40.839 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 H40.839
For H40.839to 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 H40.839 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
H40.839 is the ICD-10-CM diagnosis code for aqueous misdirection, unspecified eye. A condition where fluid in the eye flows in the wrong direction, but the specific eye affected is not documented or specified. H40.839 sits in the ICD-10-CM chapter for diseases of the eye and adnexa (h00-h59), within the section covering glaucoma (h40-h42).
H40.839 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. Despite the clinical severity of aqueous misdirection, its risk adjustment impact is limited to the prescription drug model. No hierarchies apply.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for H40.839 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code only when laterality cannot be determined from the medical record
- •Query the provider if possible to determine which eye(s) are affected for more specific coding
Clinical Significance
Aqueous misdirection, also known as malignant glaucoma or ciliary block glaucoma, is a serious condition where aqueous humor is misdirected posteriorly into the vitreous cavity rather than flowing anteriorly through the pupil. This creates a dangerous cycle of rising intraocular pressure that can be refractory to standard glaucoma treatments. It often occurs after intraocular surgery and requires urgent intervention.
Documentation Requirements
- ✓Laterality clearly specified as unspecified eye
- ✓Clinical or imaging evidence of posterior aqueous misdirection (shallow or flat anterior chamber with elevated intraocular pressure)
- ✓Intraocular pressure measurement
- ✓History of precipitating event if applicable (e.g., recent intraocular surgery, laser treatment)
- ✓Anterior segment examination findings including anterior chamber depth
- ✓B-scan ultrasound or anterior segment optical coherence tomography results if performed
- ✓Treatment approach documented (medical, laser, or surgical intervention)
Commonly Confused Codes
- •H40.211-H40.219: Acute angle-closure glaucoma (different mechanism; pupillary block vs. ciliary block)
- •H40.821-H40.829: Hypersecretion glaucoma (overproduction of aqueous, not misdirection)
- •H40.50-H40.53: Secondary glaucoma due to other eye diseases (less specific than aqueous misdirection)
- •H59.011-H59.019: Postprocedural vitreous syndrome (related but different complication)