2027 ICD-10-CM Diagnosis Code H21.512Anterior synechiae (iris), left eye
ICD-10-CM Codes›H00–H59›H15-H22›H21
- Billable — Valid for Submission
- Not Chronic
H21.512 is a billable ICD-10-CM diagnosis code for anterior synechiae (iris), left eye. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 124 through 125. 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.
- Angle closure glaucoma of left eye due to peripheral anterior synechiae
- Anterior synechiae of iris of left eye
- Peripheral anterior synechiae in inferior quadrant of angle
- Peripheral anterior synechiae in inferior quadrant of angle of left eye
- Peripheral anterior synechiae in nasal quadrant of angle
- Peripheral anterior synechiae in nasal quadrant of angle of left eye
- Peripheral anterior synechiae in superior quadrant of angle
- Peripheral anterior synechiae in superior quadrant of angle of left eye
- Peripheral anterior synechiae in temporal quadrant of angle
- Peripheral anterior synechiae in temporal quadrant of angle of left eye
- Peripheral anterior synechiae of left eye
- Secondary angle-closure glaucoma - synechial
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to H21.512: its own notes plus those printed at H21.5, H21, and Chapter 7. A note printed at a category, block or chapter applies to every code under it.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- diabetes mellitus related eye conditions (E09.3-, E10.3-, E11.3-, E13.3-)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury (trauma) of eye and orbit (S05.-)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
- syphilis related eye disorders (A50.01, A50.3-, A51.43, A52.71)
Notes
General instructions on how these codes are used.
- Use an external cause code following the code for the eye condition, if applicable, to identify the cause of the eye condition
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Eye Diseases
Even if your eyes feel healthy, you could have a problem and not know it. That's why regular eye exams are so important. Refractive errors are the most common type of vision problem that makes it hard to see clearly. But some eye conditions or diseases don't have any symptoms and can lead to a permanent loss of vision.
The full article covers:
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- What are the symptoms of eye diseases?
- Who is more likely to develop eye diseases?
- What are the treatments for eye diseases?
- Can eye diseases be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert H21.512 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About H21.512Overview
What is the ICD-10 code for anterior synechiae (iris), left eye?
The ICD-10-CM code for anterior synechiae (iris), left eye is H21.512 (sometimes written as H21512). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is H21.512 (Anterior synechiae (iris)) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report anterior synechiae (iris), left eye on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does H21.512 group to?
When anterior synechiae (iris), left eye is the principal diagnosis on an inpatient stay, it groups to MS-DRG 125, 124, with relative weights from 0.7699 to 1.2470 depending on complications. Higher weights mean higher Medicare reimbursement.
Can H21.512 be reported with Q13.2?
Not as a rule. The Excludes1 note at H21.5, which applies to H21.512, lists "corectopia (Q13.2)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What is the ICD-9 equivalent of H21.512?
Under the General Equivalence Mappings, anterior synechiae (iris), left eye converts to ICD-9-CM 364.72 (anterior synechiae). The mapping is approximate, so confirm the match fits the documentation.
