David Frame appeals pro se the dismissal of his complaint against the United *274 States based on res judicata. Frame complained that his discharge from the United States Navy violated his civil rights. Another district court dismissed Frame’s earlier complaint about his discharge against the Secretary of Defense, Secretary of the Navy, and Master Chief Petty Officer of the Navy for failure to state a claim for which relief may be granted. We affirm.

Under the doctrine of res judicata, a final judgment on the merits bars the parties to an earlier action from relitigating a claim that was or could have been raised in that action. In re Piper Aircraft Corp., 244 F.3d 1289, 1296 (11th Cir. 2001). A party who invokes the defense of res judi-cata must satisfy four elements: (1) the earlier decision must have been rendered by a court of competent jurisdiction; (2) there must have been a final judgment on the merits; (3) both cases must involve the same parties or their privies; and (4) both cases must involve the same cause of action. Id.

The district court did not err. Frame previously filed a complaint about his discharge against officers of the United States, and his earlier complaint was dismissed on the merits by another district court. The district court correctly ruled that Frame’s complaint was barred by res judicata.

AFFIRMED.