How often can I apply for the METV and can I stay in Thailand for 9 months every year?

The frequency of applying for a Multiple Entry Tourist Visa (METV) varies and is largely dependent on the specific regulations of the Thai embassy or consulate where you apply. Some embassies may limit you to one application per year. Furthermore, although it seems logical to stay for the full duration of the METV (9 months) followed by a 3-month period abroad, ultimately, your entry into Thailand is at the discretion of the immigration officer. Continuous long stays may raise questions about your status as a genuine tourist, and immigration may refuse entry regardless of holding a valid METV.