L99 — Other disorders of skin and subcutaneous tissue in diseases classified elsewhere
Is L99 billable?
Yes — L99 is billable for FY2027. L99 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. L99 may be submitted for encounters from October 1, 2026 through September 30, 2027.
L99 at a glance
| Code | L99 |
|---|---|
| Description | Other disorders of skin and subcutaneous tissue in diseases classified elsewhere |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
What Medicare edits apply to L99?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name L99 directly.
This code describes a manifestation of an underlying disease. The underlying condition must be sequenced before it, so it can never be the principal or first-listed diagnosis.
Which MS-DRGs does L99 group to?
L99 sits in MDC 09 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 606Minor Skin Disorders with MCCmedical
- 607Minor Skin Disorders without MCCmedical
How is L99 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to L99. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Amyloidosis › skin (generalized) (primary)
- Lichen › amyloidosis
- Degeneration, degenerative › cutis › amyloid
- Degeneration, degenerative › skin › amyloid
- Disease, diseased › skin › due to metabolic disorder NEC
Excludes1 — never code together
The conditions below can never be reported together with L99 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Code first
The underlying condition below must be sequenced before L99. L99 describes a manifestation and cannot be the principal or first-listed diagnosis.
- underlying disease, such as:
- amyloidosis (E85.-)
Excludes2 — not included here — inherited from Chapter 12
The conditions below are not part of L99, but a patient may have both at the same time. When documentation supports it, L99 and the excluded code may both 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)
- endocrine, nutritional and metabolic diseases (E00-E88)
- lipomelanotic reticulosis (I89.8)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
- systemic connective tissue disorders (M30-M36)
- viral warts (B07.-)
How long has L99 existed?
L99 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.
Which codes are confused with L99?
ICD-10-CM declares these codes mutually exclusive with L99 — exactly one of each pair can be correct for a given encounter.