H33.129Parasitic cyst of retina, unspecified eye

H33.129 is the ICD-10-CM diagnosis code for parasitic cyst of retina, unspecified eye. It belongs to category H33 (retinal detachments and breaks), block H30-H36 (disorders of choroid and retina) and chapter 7 (diseases of the eye and adnexa). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within H33.12, choose H33.129 (unspecified eye) only when documentation doesn't support a more specific option: right eye (H33.121), left eye (H33.122) and bilateral (H33.123).

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 121 (Acute Major Eye Infections with CC/MCC, relative weight 1.2255) and DRG 122 (Acute Major Eye Infections without CC/MCC, relative weight 0.7406), in MDC 02 (Diseases and Disorders of the Eye), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It is an unspecified code for which a more specific option (often laterality) exists, and the Medicare Code Editor flags it for review on inpatient claims.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 360.13 (parasitic endophthalmitis NOS).