Abstract: A card retention mechanism securely holds a card within a slot on a circuit board. The retention mechanism may include a carrier and a retainer. The carrier mounts to a chassis of the computer system adjacent to the card slot. The retainer may be pivotally mounted to the carrier. When the retainer is in a closed position, at least one surface of the retainer engages an endplate of the card, and the retainer engages the carrier. The engagement of the retainer and the carrier inhibits rotation of the retainer from the closed position to an open position. When the retainer is in the closed position, the retainer securely holds the card to the chassis of the computer system.