E! Online reports that the iconic anchorwoman is set to depart the programme on May 19, several weeks before the June 4 expiration date attached to her current contract.
Couric first announced her exit at the end of April, a decision dubbed unsurprising by her Today Show successor Meredith Vieira.
Scott Pelley was named as Couric's replacement last week, but will not make his first appearance until June 6 - 18 days after her departure.
It is not yet known whether Pelley's debut will now be brought forward or whether a temporary substitute anchor will be appointed by CBS.
Couric has since been rumoured to be planning a reunion with her former Today co-anchor Matt Lauer.