H42
Glaucoma in diseases classified elsewhere
H42 is a billable ICD-10-CM diagnosis code for glaucoma in diseases classified elsewhere. It is part of the FY2027 code set, effective October 1, 2026. The Alphabetic Index lists it under 6 entries. Its coding notes include a Code first instruction, 4 Excludes1 entries and 11 Excludes2 entries.
Code first
If the underlying condition listed here is present and known, sequence it first.
Excludes1
Not coded here. The listed conditions generally should not be reported together.
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (11 notes)
- 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)
Care settings
How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.
Hospice: not accepted as primary
Not accepted as the principal diagnosis on a hospice claim (bill types 081x and 082x). The Integrated OCE returns an edit for this code.
Reason: Manifestation code. Report the underlying condition first (see the Code first note).
Notes
Also from chapter/block level (1 note)
- Use an external cause code following the code for the eye condition, if applicable, to identify the cause of the eye condition
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 6 entries