Can I enter Thailand with a 60-day visa exemption and extend for 30 days for a total of 90 days?

You can enter Thailand as a US citizen under the Visa Exemption scheme, which grants you a 60-day stay. After approximately 45 days, you can apply for a 30-day extension at a local immigration office, totaling 90 days in the country. It's important to clarify that the term 'visa on arrival' is not applicable to US citizens; instead, they receive a visa exemption which allows for this process.