Ga. Unif. R. Mag. Ct. 39
A defendant may file with the answer a statement of claim against a person who is not a party to the action who is or may be liable for all or part of the plaintiff's claim. All claims arising out of the same transaction or occurrence as the plaintiff's claim may be asserted. After the answer is filed, third-party claims may only be filed with permission of the court. A plaintiff defending a counterclaim may also file such a third-party claim with permission of the court. The procedures applicable to any other action shall apply to a statement of claim filed against a third party defendant and the hearing on the entire case shall be set pursuant to OCGA § 15-10-43 calculating time limits from the day of the third-party defendant's answer.
The third-party defendant may assert a claim arising out of the same transaction or occurrence at the time of filing the answer against any other party to the action and may assert such related claims against non-parties with permission of the court. Existing parties other than the third-party plaintiff may file claims against the third party defendant arising out of the same transaction or occurrence as the original action any time before the third-party defendant's answer is due.
Ga. Unif. R. Mag. Ct. 39