Endometrial Thickening ICD-10-CM Codes

Explore ICD-10-CM codes for endometrial thickening, including simple and complex hyperplasia types, diagnosis methods, billable codes, and treatment options.

By Wynona Jugueta on Aug 8, 2025.

Fact Checked by Gale Alagos.

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What are Endometrial Thickening ICD-10-CM Codes?

Endometrial thickening, clinically referred to as endometrial hyperplasia, is a condition most commonly seen in postmenopausal women and often related to hormonal imbalance. It involves the proliferation of the endometrium—the inner lining of the uterus—leading to an abnormal thickening that may be benign or precancerous. Accurate classification with ICD-10-CM codes is essential for documentation, treatment planning, and insurance reimbursement.

Common endometrial thickening ICD-10 codes include:

N85.00 – Endometrial hyperplasia unspecified: Used when no specific type is documented; this code applies to hyperplasia N85.00 cases, including glandular cystic polypoid N85.00 or cystic glandular of endometrium.
N85.02 – Simple endometrial hyperplasia without atypia: A benign diagnosis referring to benign endometrial hyperplasia with no atypical cells.
N85.03 – Complex endometrial hyperplasia without atypia: Covers complex hyperplasia or adenomatous cystic glandular growths with no cellular abnormalities.
N85.04 – Simple endometrial hyperplasia with atypia: Includes hyperplasia with atypia, a higher-risk diagnosis often monitored for cancer development.
N85.05 – Complex endometrial hyperplasia with atypia: A significant finding with increased cancer risk, sometimes labeled as cancer endometrial hyperplasia or hyperplastic endometritis.
N85.8 – Other specified noninflammatory disorders of uterus: Covers specified noninflammatory disorders such as glandularis cystica uteri N85.00 and decidual nonspecific purulent senile conditions.
N85.9 – Noninflammatory disorder of uterus, unspecified: A catch-all code for noninflammatory disorders of the female genital tract, including uterus NOS and disease of uterus unspecified.

However, endometrial thickening alone (imaging finding) should not be coded as hyperplasia without biopsy confirmation. R93.8 – Abnormal findings on diagnostic imaging of other specified body structures is the appropriate code in such cases. This distinction is critical for correct coding and reimbursement.

Which Endometrial Thickening ICD-10-CM Codes are billable?

Accurate and billable ICD-10 codes ensure proper clinical reporting and claim reimbursement. Below are the commonly accepted billable codes for disorders of the uterus except the cervix:

N85.00: Yes, billable for unspecified benign not cancer endometrial hyperplasia.
N85.02: Yes, covers simple endometrial hyperplasia without atypia, a benign, non-cancerous condition.
N85.03: Yes, for complex endometrial hyperplasia without atypia, still benign but more structurally irregular.
N85.04: Yes, for simple hyperplasia with atypia, linked with increased malignancy potential.
N85.05: Yes, billable for complex hyperplasia with atypia, a common precursor to cancer of the endometrium.
N85.8: Yes, includes interstitialis see entries like cystica uteri N85.00 interstitialis or glandular N85.00 diagnoses.
N85.9: Yes, when the disorder of uterus unspecified is confirmed but not fully classified.

Clinical information

Endometrial hyperplasia is the result of prolonged estrogen stimulation without progesterone, often seen in perimenopausal or postmenopausal women. It falls under noninflammatory disorders of the uterus in ICD-10-CM.

Common symptoms include heavy, irregular, or prolonged menstrual bleeding.
The endometrium can develop cystic, glandular, or adenomatous changes, such as adenomatous cystic glandular hyperplasia.
Hyperplasia with atypia carries a higher risk of progressing to endometrial cancer.
Hyperplastic endometritis and cystic glandular endometrium are histological variants.
Evaluation involves pelvic ultrasound, biopsy, and sometimes hysteroscopy.
Treatments vary: hormonal therapy (e.g., progestin), hysterectomy, or ongoing surveillance, depending on patient age, reproductive goals, and whether cancer endometrial hyperplasia is suspected.
Some cases involve rare conditions such as purulent senile atrophic suppurative or puerperal hypertrophy of the uterus, leading to a bulky or enlarged uterus.

Synonyms include

Endometrial hyperplasia
Thickening of the endometrium
Hyperplasia of endometrium
Thick uterus lining
Uterus lining overgrowth

Commonly asked questions

Yes, endometrial thickening—especially when classified as complex hyperplasia with atypia—can increase the risk of developing endometrial cancer. The presence of atypical cells is a key indicator of potential progression to malignancy and requires close monitoring or treatment.

Endometrial thickening is typically diagnosed using a transvaginal ultrasound to measure the thickness of the uterine lining. If abnormalities are found, an endometrial biopsy is often performed to determine if hyperplasia or atypia is present.

Treatment depends on the type of hyperplasia and whether atypia is present, but may include hormonal therapy such as progestins, regular monitoring, or surgery. In severe or precancerous cases, a hysterectomy may be recommended to eliminate the risk of progression to cancer.

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