2027 ICD-10-CM Diagnosis Code C44.91Basal cell carcinoma of skin, unspecified
ICD-10-CM Codes›C00–D49›C43-C44›C44
- Billable — Valid for Submission
- Not Chronic
C44.91 is a billable ICD-10-CM diagnosis code for basal cell carcinoma of skin, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 606 through 607. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Skin cancers - basal cell carcinoma.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Adverse effect from PUVA photochemotherapy
- Basal cell carcinoma - adamantinoid
- Basal cell carcinoma - adenoid
- Basal cell carcinoma - first recurrence
- Basal cell carcinoma - follicular
- Basal cell carcinoma - infiltrative
- Basal cell carcinoma - keratotic
- Basal cell carcinoma - micronodular
- Basal cell carcinoma - multiple recurrences
- Basal cell carcinoma - primary
- Basal cell carcinoma - second recurrence
- Basal cell carcinoma - third recurrence
- Basal cell carcinoma of skin
- Basal cell carcinoma recurrent following cryosurgery
- Basal cell carcinoma recurrent following curettage
- Basal cell carcinoma recurrent following excision
- Basal cell carcinoma recurrent following Mohs' excision
- Basal cell carcinoma recurrent following radiotherapy
- Basal cell carcinoma with adnexal differentiation
- Basal cell carcinoma with eccrine differentiation
- Basal cell carcinoma with granular cell change
- Basal cell carcinoma with matrical differentiation
- Basal cell carcinoma with monster cells
- Basal cell carcinoma with sarcomatoid differentiation
- Basal cell carcinoma with sebaceous differentiation
- Basal cell carcinoma with signet ring change
- Basosquamous carcinoma of skin
- Circumscribed solid basal cell carcinoma
- Cystic basal cell carcinoma
- Fibroepithelioma of Pinkus
- Follicular atrophoderma
- Follicular atrophoderma and basal cell epitheliomata
- Gorlin syndrome
- Malignant basal cell neoplasm of skin
- Malignant neoplasm of skin caused by radiation
- Malignant neoplasm of skin with pilar differentiation
- Metastatic basal cell carcinoma
- Nodular basal cell carcinoma of skin
- Nodulo-ulcerative basal cell carcinoma
- Pigmented basal cell carcinoma
- Primary basal cell carcinoma - adenoid
- Primary basal cell carcinoma - infiltrative
- Primary basal cell carcinoma - micronodular
- Primary basal cell carcinoma with eccrine differentiation
- Primary basosquamous carcinoma of skin
- Primary fibroepithelioma of Pinkus
- Primary nodular basal cell carcinoma of skin
- Primary sclerosing morpheic basal cell carcinoma
- Primary superficial basal cell carcinoma
- Primary trichilemmal carcinoma
- PUVA therapy-associated basal cell carcinoma
- Recurrent basal cell carcinoma
- Sclerosing morpheic basal cell carcinoma
- Superficial basal cell carcinoma
- Trichilemmal carcinoma
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to C44.91: its own notes plus those printed at C44 and Chapter 2. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- malignant neoplasm of sebaceous glands
- malignant neoplasm of sweat glands
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Notes
General instructions on how these codes are used.
- Functional activity
- All neoplasms are classified in this chapter, whether they are functionally active or not. An additional code from Chapter 4 may be used, to identify functional activity associated with any neoplasm.
- Morphology [Histology]
- Chapter 2 classifies neoplasms primarily by site (topography), with broad groupings for behavior, malignant, in situ, benign, etc. The Table of Neoplasms should be used to identify the correct topography code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology (histologic type) is included in the category and codes.
- Primary malignant neoplasms overlapping site boundaries
- A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned.
- Malignant neoplasm of ectopic tissue
- Malignant neoplasms of ectopic tissue are to be coded to the site mentioned, e.g., ectopic pancreatic malignant neoplasms are coded to pancreas, unspecified (C25.9).
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name C44.91, its category, or a range that includes it.
Applicable To 1
These notes mention C44.91.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Carcinoma (malignant) See Also: Neoplasm, by site, malignant;
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Skin Basal Cell Cancer
the most frequently seen skin cancer. it arises from basal cells of the epidermis and pilosebaceous units. clinically it is divided into the following types: nodular, ulcerative, superficial, multicentric, erythematous, and sclerosing or morphea-like. more than 95% of these carcinomas occur in patients over 40. they develop on hair-bearing skin, most commonly on sun-exposed areas. approximately 85% are found on the head and neck and the remaining 15% on the trunk and extremities. basal cell carcinoma usually grows in a slow and indolent fashion. however, if untreated, the tumor may invade the subcutaneous fat, skeletal muscle and bone. distant metastases are rare. excision, curettage and irradiation cure most basal cell carcinomas.
Table of NeoplasmsClinical
Anatomical sites in the Table of Neoplasms that reference this code family.
| Site | Malig. Primary | Malig. Secondary | Ca in situ | Benign | Uncertain | Unspec. |
|---|---|---|---|---|---|---|
| skin NOS › basal cell carcinoma | C44.91 | – | – | – | – | – |
| skin NOS › limb NEC › basal cell carcinoma | C44.91 | – | – | – | – | – |
Patient EducationClinical
Skin Cancer
Skin cancer is the most common form of cancer in the United States. The two most common types are basal cell cancer and squamous cell cancer. They usually form on the head, face, neck, hands, and arms. Another type of skin cancer, melanoma, is more dangerous but less common.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert C44.91 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C44.91Overview
What is the ICD-10 code for basal cell carcinoma of skin, unspecified?
The ICD-10-CM code for basal cell carcinoma of skin, unspecified is C44.91 (sometimes written as C4491). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is C44.91 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report basal cell carcinoma of skin, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does C44.91 group to?
When basal cell carcinoma of skin, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 607, 606, with relative weights from 0.8772 to 1.5721 depending on complications. Higher weights mean higher Medicare reimbursement.
Can C44.91 be reported with C46.0?
Not as a rule. The Excludes1 note at C44, which applies to C44.91, lists "Kaposi's sarcoma of skin (C46.0)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What is the ICD-9 equivalent of C44.91?
Under the General Equivalence Mappings, basal cell carcinoma of skin, unspecified converts to ICD-9-CM 173.91 (basal cell ca skin NOS). The mapping is a direct match.
