H40.20Unspecified primary angle-closure glaucoma

H40.20 is the ICD-10-CM diagnosis code for unspecified primary angle-closure glaucoma. It belongs to category H40 (glaucoma), block H40-H42 (glaucoma) and chapter 7 (diseases of the eye and adnexa). It is a header code, so it can't be reported by itself; one of its 5 subcodes must be used instead.

Within H40.2, choose H40.20 (Unspecified primary angle-closure glaucoma) only when documentation doesn't support a more specific option: acute angle-closure glaucoma (H40.21), chronic angle-closure glaucoma (H40.22), intermittent angle-closure glaucoma (H40.23) and residual stage of angle-closure glaucoma (H40.24).

Codes in this range require a 7th character: 0 for stage unspecified, 1 for mild stage, 2 for moderate stage, 3 for severe stage and 4 for indeterminate stage. Use placeholder "X" characters to fill any empty positions before the 7th character.

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