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/vessels, and others who require a TWIC®. The TWIC smart card credential is mostly based off of the PIV (Personal Identity Verification) specification. TSA conducts a security threat assessment (background check) to determine a person’s eligibility and issues the credential. U.S. citizens and non-U.S. citizens in certain immigrant/non-immigrant categories may apply for the credential. Most mariners licensed by the U.S. Coast Guard also require a credential.