Is the 45-day visa-free exemption to Thailand still valid and how many times can a dual citizen enter without a visa?

The 45-day visa-free exemption is still valid for qualifying countries until April 1st. While there is a common belief that visa-exempt entries are limited to twice per calendar year, this primarily applies to entries by land. For individuals with dual citizenship (like US and Vietnam), there is technically no limit on the number of entries by air; however, immigration officers may question frequent entries.