8 C.F.R. § 214.203
Period of admission
(a) T-1 Principal. T-1 nonimmigrant status may be approved for a period not to exceed 4 years, except as provided in section 214(o)(7) of the Act.
(b) Derivative family members. A derivative family member who is otherwise eligible for admission may be granted T-2, T-3, T-4, T-5, or T-6 nonimmigrant status for an initial period that does not exceed the expiration date of the initial period approved for the T-1 principal applicant, except as provided in section 214(o)(7) of the Act.
(c) Notice. At the time an applicant is approved for T nonimmigrant status or receives an extension of T nonimmigrant status, USCIS will notify the applicant when their T nonimmigrant status will expire. USCIS also will notify the applicant that the failure to apply for adjustment of status to lawful permanent resident during the period of T nonimmigrant status, as set forth in 8 CFR 245.23, will result in termination of the applicant's T nonimmigrant status in the United States at the end of the 4-year period or any extension.