Thickened Endometrium ICD-10-CM Codes

What ICD-10 codes are used for thickened endometrium?

Thickened endometrium, or endometrial hyperplasia, is a condition often observed in postmenopausal women and is characterized by endometrial thickening due to excessive proliferation of the uterine lining. It can stem from hormonal imbalances and may present as benign or with atypical features, warranting close clinical attention. Below are the most commonly used ICD-10 codes to classify abnormal findings associated with this condition:

• N85.00 – Unspecified endometrial hyperplasia: This code applies to endometrial hyperplasia unspecified, where the type (simple or complex) and the presence of atypia are not clearly documented.
• N85.02 – Simple endometrial hyperplasia without atypia: For cases of benign endometrial hyperplasia that do not show abnormal cellular changes.
• N85.03 – Complex endometrial hyperplasia without atypia: Used when the glandular architecture is altered without atypical cellular characteristics.
• N85.04 – Simple endometrial hyperplasia with atypia: Indicates a simple form of hyperplasia where atypical cells are present, elevating cancer risk.
• N85.05 – Complex endometrial hyperplasia with atypia: This code is reserved for the most concerning cases of endometrial intraepithelial neoplasia, often considered a precancerous state.

Which thickened endometrium ICD codes are billable?

Identifying billable ICD-10 codes is crucial for accurate medical billing and reimbursement. All of the codes listed below are considered billable under the 2025 ICD-10-CM code set:

• N85.00: Yes, covers endometrial hyperplasia unspecified.
• N85.02: Yes, specifies simple hyperplasia without atypia.
• N85.03: Yes, valid for complex hyperplasia without atypia.
• N85.04: Yes, billable for simple hyperplasia with atypia.
• N85.05: Yes, identifies complex hyperplasia with atypia.

Clinical information

Endometrial thickening is commonly detected in women undergoing evaluations for abnormal uterine bleeding, particularly in postmenopausal patients. The endometrium, which lines the uterus, responds to estrogen levels; excess or unopposed estrogen can lead to benign endometrial hyperplasia or more concerning conditions like endometrial intraepithelial neoplasia.

This condition can manifest as:

• Heavy, prolonged, or irregular menstrual bleeding
• Abnormal findings on transvaginal ultrasound
• Risk of progression to endometrial carcinoma, especially in atypical cases

Diagnostic imaging, such as pelvic ultrasound, is often the first step in detecting endometrial thickening. However, diagnosis is confirmed through an endometrial biopsy, which helps differentiate between benign and atypical hyperplasia or rule out malignancy.

Conditions affecting the genitourinary system may also coexist or complicate diagnosis, especially in women with concurrent inflammatory diseases or other abdominal region symptoms.

Treatment depends on:

• Type of hyperplasia (simple vs. complex, with or without atypia)
• Patient’s age and fertility preservation goals
• Risk profile for progression to cancer

Therapeutic options include progestin therapy, endometrial ablation, or hysterectomy for recurrent or high-risk cases. Continuous monitoring with follow-up imaging and histology is critical, particularly for patients with atypical changes.

Synonyms include:

• Endometrial hyperplasia
• Hyperplasia of endometrium
• Thick uterus lining
• Uterus lining overgrowth