Your tax home must be in a foreign country, or countries, throughout the period of bona fide residence or physical presence, whichever applies. For this purpose, your period of physical presence is the 330 full days during which you were present in a foreign country, and not the 12 consecutive months during which those days occurred.
The location of your tax home will depend on the circumstances. Normally, your tax home is considered to be the general area of your regular or principal place of business, employment, or post of duty, regardless of where you maintain your family residence. If you do not have a regular or principal place of business because of the nature of your trade or business, your tax home may then be the place where you normally live.
You are not considered to have a tax home in a foreign country for any period during which your “abode” is in the United States. Abode is more of a domestic term and depends on where you maintain your economic, family, and personal ties. However, if while working abroad you are temporarily present in the United States, or you maintain a dwelling in the United States (whether or not that dwelling is used by your spouse and dependents), it does not necessarily mean that your abode is in the United States during that time.
The location of your tax home may depend on whether your assignment in a foreign country is temporary or indefinite. Normally, if you expect your assignment in one location outside the U.S. to last one year or less, it is considered temporary. In this case, you could deduct your travel, meals, and lodging expenses according to the tax rules for deducting expenses while traveling away from home on business. If the assignment is expected to last more than one year, it is indefinite. In this case, you could not deduct travel, lodging and meals, but you may qualify for the foreign earned income exclusion, and the foreign housing exclusion or deduction.