2021 ICD-10-CM Code D05.91

Unspecified type of carcinoma in situ of right breast

Version 2021

Valid for Submission

D05.91 is a billable diagnosis code used to specify a medical diagnosis of unspecified type of carcinoma in situ of right breast. The code D05.91 is valid during the fiscal year 2021 from October 01, 2020 through September 30, 2021 for the submission of HIPAA-covered transactions.

Unspecified diagnosis codes like D05.91 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

ICD-10:D05.91
Short Description:Unspecified type of carcinoma in situ of right breast
Long Description:Unspecified type of carcinoma in situ of right breast

Code Classification

Convert D05.91 to ICD-9 Code

The General Equivalency Mapping (GEM) crosswalk indicates an approximate mapping between the ICD-10 code D05.91 its ICD-9 equivalent. The approximate mapping means there is not an exact match between the ICD-10 code and the ICD-9 code and the mapped code is not a precise representation of the original code.

Information for Patients


Breast Cancer

Breast cancer affects one in eight women during their lives. No one knows why some women get breast cancer, but there are many risk factors. Risks that you cannot change include

Other risks include obesity, using hormone replacement therapy (also called menopausal hormone therapy), taking birth control pills, drinking alcohol, not having children or having your first child after age 35, and having dense breasts.

Symptoms of breast cancer may include a lump in the breast, a change in size or shape of the breast, and discharge from a nipple. Breast self-exams and mammography can help find breast cancer early, when it is most treatable. One possible treatment is surgery. It could be a lumpectomy or a mastectomy. Other treatments include radiation therapy, chemotherapy, hormone therapy, and targeted therapy. Targeted therapy uses substances that attack cancer cells without harming normal cells.

Men can have breast cancer, too, but it is rare.

NIH: National Cancer Institute


[Learn More in MedlinePlus]

Breast cancer Breast cancer is a disease in which certain cells in the breast become abnormal and multiply uncontrollably to form a tumor. Although breast cancer is much more common in women, this form of cancer can also develop in men. In both women and men, the most common form of breast cancer begins in cells lining the milk ducts (ductal cancer). In women, cancer can also develop in the glands that produce milk (lobular cancer). Most men have little or no lobular tissue, so lobular cancer in men is very rare.In its early stages, breast cancer usually does not cause pain and may exhibit no noticeable symptoms. As the cancer progresses, signs and symptoms can include a lump or thickening in or near the breast; a change in the size or shape of the breast; nipple discharge, tenderness, or retraction (turning inward); and skin irritation, dimpling, redness, or scaliness. However, these changes can occur as part of many different conditions. Having one or more of these symptoms does not mean that a person definitely has breast cancer.In some cases, cancerous tumors can invade surrounding tissue and spread to other parts of the body. If breast cancer spreads, cancerous cells most often appear in the bones, liver, lungs, or brain. Tumors that begin at one site and then spread to other areas of the body are called metastatic cancers.A small percentage of all breast cancers cluster in families. These cancers are described as hereditary and are associated with inherited gene mutations. Hereditary breast cancers tend to develop earlier in life than noninherited (sporadic) cases, and new (primary) tumors are more likely to develop in both breasts.
[Learn More in MedlinePlus]

Code History

  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016 (First year ICD-10-CM implemented into the HIPAA code set)