C50.912 Malignant neoplasm of unspecified site of left female breast

Billable ICD-10-CM code, FY2026.

Applies from C50 Malignant neoplasm of breast

Includes

• connective tissue of breast
• Paget's disease of breast
• Paget's disease of nipple

Excludes1 (never code together)

• skin of breast (C44.501, C44.511, C44.521, C44.591)

Use additional code

• code to identify estrogen, and other hormones and factors receptor status (Z17.-)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 23 — Prostate, Breast, and Other Cancers and Tumors
• CMS-HCC V22: HCC 12 — Breast, Prostate, and Other Cancers and Tumors
• RxHCC V08: HCC 22 — Prostate, Breast, Bladder, and Other Cancers and Tumors
• ESRD V24: HCC 12

MS-DRG index

Defines the logic of DRG(s) 582-583 in MDC 09.

Approximate ICD-9-CM (GEMs)

• 174.9 Malignant neoplasm of breast (female), unspecified (approximate)

Code annotations containing back-references to C50.912

Back-references to C50

• Type 1 Excludes: C49 Malignant neoplasm of other connective and soft tissue ("malignant neoplasm of connective tissue of breast (C50.-)")
• Type 1 Excludes: C49.3 Malignant neoplasm of connective and soft tissue of thorax ("malignant neoplasm of breast (C50.-)")
• Type 1 Excludes: D05 Carcinoma in situ of breast ("Paget's disease of breast or nipple (C50.-)")
• Type 2 Excludes: D05 Carcinoma in situ of breast ("malignant neoplasm of breast (C50.-)")
• Code Also: D61.82 Myelophthisis ("malignant neoplasm of breast (C50.-)")
• Code First: D75.81 Myelofibrosis ("malignant neoplasm of breast (C50.-)")
• Code First: Z17 Estrogen, and other hormones and factors receptor status ("malignant neoplasm of breast (C50.-)")
• Code First: Z79.81 Long term (current) use of agents affecting estrogen receptors and estrogen levels ("malignant neoplasm of breast (C50.-)")
• Code Also: Z91.B Personal risk factor of exposure to diethylstilbestrol ("conditions classifiable to C50.-")

Nearby codes

• C50.822 Malignant neoplasm of overlapping sites of left male breast
• C50.829 Malignant neoplasm of overlapping sites of unspecified male breast
• C50.9 Malignant neoplasm of breast of unspecified site
• C50.91 Malignant neoplasm of breast of unspecified site, female
• C50.911 Malignant neoplasm of unspecified site of right female breast
• C50.912 Malignant neoplasm of unspecified site of left female breast (this code)
• C50.919 Malignant neoplasm of unspecified site of unspecified female breast
• C50.92 Malignant neoplasm of breast of unspecified site, male
• C50.921 Malignant neoplasm of unspecified site of right male breast
• C50.922 Malignant neoplasm of unspecified site of left male breast
• C50.929 Malignant neoplasm of unspecified site of unspecified male breast