Gunna is accused of conspiring to violate the Racketeer Influenced and Corrupt Organizations Act.
He entered an Alford plea, in which he acknowledges evidence would likely lead to a guilty verdict.
The rapper has been denied bond three times since his arrest in May.
Jeffrey Lamar Williams, aka Young Thug, is accused of participating in criminal street gang activity.
He pleaded not guilty earlier this month.
His attorney has filed a motion to prevent prosecutors from using the rapper's lyrics as evidence against him when his case goes to trial.