The CSI: Crime Scene Investigation spinoff is currently in its eighth season, with a finale set for May 11.
The series has yet to be officially renewed for a ninth season, leading to rumours of a possible cancellation after an announcement about its future was expected earlier this month.
However, Sinise - who plays Detective Mac Taylor in the show - dismissed the reports on Twitter.
"CSI: NY has not been cancelled," he wrote. "We are back on the air March 30 with five great new episodes. Tune in."
The show's executive producer Zach Reiter recently ruled out a cliffhanger at the end of its current season, as he was unsure of its renewal.
"What we're trying to build is a story that has enough resolution that if it truly is a series finale, it feels good," he said in January. "But at the same time, we're not shutting the door completely."
The show airs on Fridays at 9/8c on CBS.
> CBS sets season finale dates: CSI, NCIS, Big Bang Theory, more