H31.121Diffuse secondary atrophy of choroid, right eye

H31.121 is the ICD-10-CM diagnosis code for diffuse secondary atrophy of choroid, right eye. It belongs to category H31 (other disorders of choroid), 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 H31.12 (diffuse secondary atrophy of choroid), H31.121 is specifically for diffuse secondary atrophy of choroid, right eye. Related codes cover left eye (H31.122), bilateral (H31.123) and unspecified eye (H31.129).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 124 (Other Disorders of the Eye with MCC or Thrombolytic Agent, relative weight 1.2471) and DRG 125 (Other Disorders of the Eye without MCC, relative weight 0.7702), 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 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 362.77 (dystrophies primarily involving Bruch's membrane) and 363.42 (diffuse secondary atrophy of choroid).