49 CFR § 1572.23 - TWIC expiration.
(1) The TWIC was issued based on a determination that the applicant completed a comparable threat assessment. If issued pursuant to a comparable threat assessment, the TWIC expires five years from the date on the credential associated with the comparable threat assessment.
(2) The applicant is in a lawful nonimmigrant status category listed in 1572.105(a)(7), and the status expires, the employer terminates the employment relationship with the applicant, or the applicant otherwise ceases working for the employer. Under any of these circumstances, TSA deems the TWIC to have expired regardless of the expiration date on the face of the TWIC.