The Transportation Worker Identification Credential, also known as TWIC®, is required by the Maritime Transportation Security Act for workers who need access to secure areas of the nation’s maritime facilities and vessels. TSA conducts a security threat assessment (background check) to determine a person’s eligibility and issues the credential. U.S. citizens and immigrants in certain immigration categories may apply for the credential. Most mariners licensed by the U.S. Coast Guard also require a credential. Regarding card usage and facility access requirements, please contact the U.S. Coast Guard