What type of military ID card has a portrait format and a chip?

The Common Access Card (CAC) is a military ID card specifically designed to provide secure access to DoD computer systems and facilities. It features a portrait format and integrates a smart chip, which enhances security by enabling various authentication methods. This chip allows for encrypted communication and supports multiple applications, including access to classified information and secure emails.

The design and technology of the CAC make it distinct from other military IDs, which may not include the smart chip or the same security features. The Old Military ID, Dependent Military ID, and Retired Military ID do not have the same level of security integration or the modernized design that includes a chip, making the Common Access Card the correct choice for this question.