L99Other disorders of skin and subcutaneous tissue in diseases classified elsewhere

L99 is the ICD-10-CM diagnosis code for other disorders of skin and subcutaneous tissue in diseases classified elsewhere. It belongs to block L80-L99 (other disorders of the skin and subcutaneous tissue) and chapter 12 (diseases of the skin and subcutaneous tissue). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Don't report L99 together with the conditions in its Excludes1 note: skin disorders in diabetes (E08-E13 with .62-), skin disorders in gonorrhea (A54.89) and skin disorders in syphilis (A51.31, A52.79).

Code first underlying disease, such as: amyloidosis (E85.-).

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 606 (Minor Skin Disorders with MCC, relative weight 1.5728) and DRG 607 (Minor Skin Disorders without MCC, relative weight 0.8772), in MDC 09 (Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast), 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 is a manifestation code, so it describes the effect of an underlying disease and can't be the principal diagnosis. Code the underlying condition first.

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 701.8 (other specified hypertrophic and atrophic conditions of skin) and 709.8 (other specified disorders of skin).