The Retirement Visa, also known as the Non-Immigrant O-A Visa, is a popular visa category in Thailand for foreigners who wish to retire in the country. The requirements and specific details of the Retirement Visa may vary over time, so it's always best to consult with the Thai authorities or the Royal Thai Embassy/Consulate for the most up-to-date information. However, as of my knowledge cutoff in September 2021, here are some key points about the Retirement Visa:

1. Age Requirement: Applicants must be at least 50 years old.
2. Financial Requirements: You need to meet specific financial criteria to qualify for the Retirement Visa. The most common requirement is to show proof of a monthly income or a combination of funds in a Thai bank account. The minimum income or funds required may vary depending on the country of origin.
3. Health Insurance: Applicants are generally required to have health insurance coverage during their stay in Thailand. The insurance policy should provide a minimum coverage amount, as specified by Thai authorities.
4. Visa Validity: Initially, the Retirement Visa is typically granted for a one-year period. It can be extended on an annual basis in Thailand. Each extension requires you to meet the financial and other requirements.
5. Reporting: Retirement Visa holders are required to report their address to the local immigration office every 90 days.
6. Employment Limitations: Holders of the Retirement Visa are generally not allowed to work in Thailand. If you wish to work, you would need to obtain a work permit separately.

It's important to note that visa regulations and requirements can change, and it's advisable to consult with the Thai immigration authorities or the Royal Thai Embassy/Consulate for the most up-to-date and accurate information on the Retirement Visa.