ICD-10 Codes for Thyroid Nodules
The primary ICD-10 codes for thyroid nodules are E04.1 (Nontoxic single thyroid nodule) for solitary nodules and E04.2 (Nontoxic multinodular goiter) for multiple nodules. 1
Primary Diagnostic Codes
- E04.1 (Nontoxic single thyroid nodule) is the appropriate code for patients with a documented solitary benign thyroid nodule undergoing monitoring ultrasound 1
- E04.2 (Nontoxic multinodular goiter) should be used for patients with multiple thyroid nodules under surveillance 1
- D44.0 (Neoplasm of uncertain behavior of thyroid gland) may be appropriate for nodules with indeterminate features on prior imaging or cytology before definitive intervention 1
Secondary and Supplemental Codes
- Z85.850 (Personal history of malignant neoplasm of thyroid) should be added as a secondary code for patients with a history of treated thyroid cancer undergoing surveillance for recurrence 1
- This secondary code is critical for documenting medical necessity when monitoring for potential recurrence in cancer survivors 1
Critical Coding Pitfalls to Avoid
- Never use Z12.31 (Encounter for screening for malignant neoplasm of thyroid) for surveillance of known nodules, as this code is reserved exclusively for screening in asymptomatic patients without known thyroid disease 1
- Avoid R93.89 (Abnormal findings on diagnostic imaging of other specified body structures) as the primary code when a definitive thyroid nodule diagnosis exists, as it is too nonspecific and may result in insurance denials 1
- Do not code as C73 (malignant neoplasm of thyroid) unless there is pathologic confirmation of malignancy, as this can lead to insurance denials and inappropriate patient anxiety 1
Clinical Context for Code Selection
- Thyroid nodules are extremely common, detected in up to 65% of the general population, with approximately 50% of individuals having at least one nodule by age 60 2, 3
- Only approximately 10% of thyroid nodules harbor clinically significant cancer, making accurate coding essential to justify appropriate surveillance versus intervention 2
- Nodules ≥2 cm warrant evaluation due to increased malignancy risk, and this clinical context should be documented to support medical necessity of surveillance imaging 1
- Ultrasound surveillance is typically recommended for nodules classified as Bethesda II (benign) with a very low malignancy risk of 1-3%, which supports the use of E04.1 or E04.2 codes for follow-up imaging 1