Texas Election Code - ELEC § 101.001. Eligibility

(A) a member of the armed forces of the United States, or the spouse or a dependent of a member;

(B) a member of the merchant marine of the United States, or the spouse or a dependent of a member;

(B-1) a member of the Texas National Guard or the National Guard of another state or a member of a reserve component of the armed forces of the United States serving on active duty under an order of the president of the United States or activated on state orders, or the spouse or dependent of a member;  or

(C) domiciled in this state but temporarily living outside the territorial limits of the United States and the District of Columbia.