AJCC 7th Edition TNM Staging for Well-Differentiated Thyroid Cancer (21)
| Stage | T | N | M |
| Patients < 45 years old | |||
| Stage I | Any T | Any N | M0 |
| Stage II | Any T | Any N | M1 |
| Patients ≥ 45 years old | |||
| Stage I | T1 | N0 | M0 |
| Stage II | T2 | N0 | M0 |
| Stage III | T3 | N0 | M0 |
| T1 or T2 or T3 | N1a | M0 | |
| Stage IVA | T1 or T2 or T3 | N1b | M0 |
| T4a | Any N | M0 | |
| Stage IVB | T4b | Any N | M0 |
| Stage IVC | Any T | Any N | M1 |
T: tumor; N: nodes; M: distant metastases.