Endocrinology ICD-10-CM codes

Diabetes coding should reflect every documented complication with combination codes from a single category: E11.22 with CKD, E11.40 and E11.42 for neuropathy, E11.36 for diabetic cataract, E11.65 with hyperglycemia, and E11.21 for nephropathy. Assign as many E11 codes as there are complications. Type 1 uses the parallel E10 series. The medication Z codes complete the picture: Z79.4 for insulin, Z79.84 for oral agents, and Z79.85 for injectable non-insulin drugs, the code that covers GLP-1 receptor agonists.

Thyroid volume splits between hypothyroidism (E03.9, or E89.0 when postsurgical or post-ablation), Hashimoto's autoimmune thyroiditis (E06.3), thyrotoxicosis (E05.90 without crisis), and nodular disease, where E04.1 (single nodule) and E04.2 (multinodular goiter) drive ultrasound and biopsy claims. Abnormal thyroid function studies without a settled diagnosis are R94.6. Thyroid cancer is C73 during active treatment and Z85.850 once treatment is complete and surveillance begins.

Prediabetes (R73.03) and impaired fasting glucose (R73.01) are distinct from diabetes and support prevention services; do not code E11.9 for a patient who has not been diagnosed with diabetes. Obesity management pairs E66.01 or E66.9 with the BMI (Z68.35, Z68.41), and metabolic syndrome is E88.810 with additional codes for each component. For bone health, M81.0 covers age-related osteoporosis without current fracture, with Z87.310 for a healed osteoporotic fracture history and E55.9 and E21.0 or E21.3 for the vitamin D and parathyroid workup.