S. Epatha Merkerson as Lt. Anita Van Buren in "Law & Order"

*Turns out twenty years is enough for S. Epatha Merkerson. 

After starring on NBC’s “Law & Order” for two decades – longer than any other cast member on the series – the actress has asked producers to release her after the current 20th season.

According to the Hollywood Reporter, Merkerson made the request before the cop drama was to enter production on the last episode of the season so her character could be given an appropriate send-off.

The TV veteran joined “L&O” midway through season one and has appeared in almost 400 episodes playing no-nonsense supervisor Lt. Anita Van Buren.

Merkerson did not have a deal in place for next season’s “Law & Order.” That season is still up in the air as a pickup by NBC depends on the network’s ability to ink an off-network deal with TNT.

The cable channel, which carries “L&O” reruns, has no obligation to pick up more seasons beyond Season 20. NBC has been looking to the TNT license fee to offset the cost of production in order to renew “L&O” for a record-setting 21st campaign.

The chances for that happening have increased recently as TNT has reportedly made an offer to NBC.