2026 ICD-10-CM Diagnosis Code H21.321Implantation cysts of iris, ciliary body or anterior chamber, right eye
ICD-10-CM Codes›H00–H59›H15-H22›H21
- Billable — Valid for Submission
- Not Chronic
H21.321 is a billable ICD-10-CM diagnosis code for implantation cysts of iris, ciliary body or anterior chamber, right eye. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 124 through 125. Coders also document this condition as cyst of anterior chamber of eye. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified eye disorders.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Cyst of anterior chamber of eye
- Implantation cyst of anterior chamber of eye
- Implantation cyst of anterior chamber of right eye
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Eye Diseases
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Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert H21.321 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About H21.321Overview
Is H21.321 (Implantation cysts of iris, ciliary body or anterior chamber) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report implantation cysts of iris, ciliary body or anterior chamber, right eye on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does H21.321 group to?
When implantation cysts of iris, ciliary body or anterior chamber, right eye is the principal diagnosis on an inpatient stay, it groups to MS-DRG 124, 125, with relative weights from 0.7678 to 1.3231 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of H21.321?
Under the General Equivalence Mappings, implantation cysts of iris, ciliary body or anterior chamber, right eye converts to ICD-9-CM 364.61 (implantation cysts). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
