How often can I apply for a single entry tourist visa for Thailand?

This is a classic "snowbird" travel pattern, and doing this 2 times a year for 2–3 months each time is generally safe and very doable, but there are strict boundaries you need to know to avoid problems at the border.

Here is the direct, professional breakdown for your winter plans:

How often can you apply? Thai Embassies and Consulates do not have a hard legal limit on Single-Entry Tourist Visas (TR), but as a general rule of thumb, getting 2 consecutive tourist visas per calendar year is perfectly fine. Once you hit 3 or more in a short period, immigration officers at the airport may start questioning whether you are trying to live in Thailand illegally without a proper long-term visa.

Will they frown upon your plan? If you are only entering 2 times a year (e.g., Oct-Nov, then Jan-Feb) and spending the rest of the year back home in Alaska, immigration will not look down on you. They can see your travel history shows you are a genuine seasonal tourist escaping the winter, not someone working illegally or abusing the system.

A Better Alternative to Consider: Since you want to enter multiple times during the winter, look into the Multiple-Entry Tourist Visa (METV). Applied for while you are still home in the US, it is valid for 6 months and allows unlimited entries of up to 60 days per entry. This completely saves you from having to apply for two separate visas or sitting in immigration lines for extensions while you are in Thailand.

Crucial Reminder: No matter which visa you choose, remember that the online Thailand Digital Arrival Card (TDAC) registration is now mandatory and must be completed within 3 days before each flight into the country.

Your snowbird plan is excellent. Just stick to 2 entries max per winter season on tourist visas, or grab the METV for total peace of mind. Safe travels from Alaska! 🌹

The number of entries allowed is not determined by the type of visa, but by a separate Entry Permit. There are single and multiple entry permits, each type with a different price.

You can be issued with as many tourist visas as the consulate you apply at will issue, however having a visa is does not guarantee you will be allowed to enter. Two entries per annum should be fine but you mention the possibility of a third entry which could be problematic if you've already spent 150 days or more inside Thailand, in which case it might be easier just to go with retirement visas. The Non-OA visa might be the most suitable as it doesn't require a Thai bank account but does require insurance, medical and police checks

I do the Jan-Mar stay and get the SETV with a 30 day extension. I'm pretty sure there is no problem doing this twice a calendar year, but as you seem to want to do this all within a 6 month period, the METV could work better.

If over 50, one of the retirement Visas may be even better.