ICD‑10 Coding Guidelines for Polycystic Ovary Syndrome (PCOS) Evaluation

Primary Diagnostic Code

Use ICD‑10 code E28.2 (Polycystic ovarian syndrome) as the primary diagnosis when ordering a hormonal panel (FSH, LH, progesterone, estradiol, testosterone) to evaluate suspected PCOS. 1
E28.2 is appropriate even before a definitive diagnosis if clinical suspicion warrants hormonal evaluation for PCOS. 1
This code covers the laboratory work needed to assess the Rotterdam criteria— androgen excess, ovulatory dysfunction, and exclusion of mimicking disorders. 1

Before confirming PCOS, exclude thyroid disease, hyperprolactinemia, and non‑classic congenital adrenal hyperplasia (CAH). 1
E03.9 (Hypothyroidism, unspecified) or E05.90 (Thyrotoxicosis, unspecified) justify TSH and free T4 testing to rule out thyroid disorders. 1
E22.1 (Hyperprolactinemia) justifies prolactin measurement to exclude prolactinoma or medication‑induced hyperprolactinemia. 1
E25.0 (Congenital adrenal hyperplasia) authorizes early‑morning 17‑hydroxyprogesterone (17‑OHP) testing to exclude 21‑hydroxylase deficiency. 1

N91.2 (Amenorrhea, unspecified) for patients with absent menses ≥ 3 months. 2
N91.5 (Oligomenorrhea, unspecified) for menstrual cycles > 35 days or < 8 cycles per year. 2
L68.0 (Hirsutism) when Ferriman‑Gallwey score is ≥ 4–6, indicating clinical hyperandrogenism. 2
E28.1 (Androgen excess, not elsewhere classified) for biochemical hyperandrogenism when PCOS has not yet been confirmed. 1
N97.0 (Female infertility associated with anovulation) for patients seeking fertility evaluation. 2

Metabolic screening is required at PCOS diagnosis to justify glucose and lipid testing. 2
R73.09 (Other abnormal glucose) or E11.9 (Type 2 diabetes mellitus without complications) authorize a 75‑g oral glucose tolerance test (OGTT) to detect impaired glucose tolerance or diabetes. 2
E78.5 (Hyperlipidemia, unspecified) authorizes a fasting lipid panel; dyslipidemia in PCOS occurs independent of obesity. 2
E66.9 (Obesity, unspecified) for BMI ≥ 30 kg/m² and E66.01 (Morbid obesity due to excess calories) for BMI ≥ 40 kg/m². 2
Z68.__ codes document the exact BMI for risk stratification. 2

Do not use R79.89 or R79.9 as primary codes; they are nonspecific and may lead to claim denial.
Do not assign E28.2 until at least two of the three Rotterdam criteria are documented and thyroid disease, hyperprolactinemia, and non‑classic CAH have been excluded. 1
Do not use N94.6 (Dysmenorrhea, unspecified) or N92.0 (Excessive and frequent menstruation with regular cycle) when the primary issue is oligomenorrhea or amenorrhea, as they fail to capture the anovulatory nature of PCOS. 2
Always code obesity (E66.9) separately when present, because it significantly impacts metabolic risk and treatment planning. 2

FSH/LH ratio > 2: use E28.2 or E28.1 to capture the elevated ratio commonly seen in PCOS. 4
Total/free testosterone: the most frequently abnormal biochemical marker, with ~70 % sensitivity for PCOS. 3
Progesterone < 1–6 nmol/L in the mid‑luteal phase indicates anovulation; code with E28.2 or N97.0. 2
17‑OHP > 200 ng/dL: triggers an ACTH stimulation test to confirm non‑classic CAH; code with E25.0. 1
AMH ≥ 5.28 ng/mL provides high sensitivity (87 %) and specificity (97 %) for PCOS across phenotypes. (Reference excluded due to “ignore ref”)