Season three of the karate drama - which pits Karate Kid rivals Danny LaRusso (Macchio) and Johnny Lawrence (Zabka) against each other once more, drops on 1 January - and a fourth outing is also set to start shooting in the New Year.
The new series delves deeper in to some characters' pasts, as well as picking up from the fallout of the dramatic high school battle that closed season two and left Miguel Diaz fighting for his life.
Both actors said the young ensemble cast meant the Cobra Kai story could run for another three seasons yet.
"We're more than thinking about season four - we start work on it in a few weeks," said Zabka. "And beyond. The show has a long way to go and we're really having fun with it."
Macchio told LADbible: "The writers have always felt they had six seasons in their head, where the story arcs can go. So that should all land when the time is right.
"You don't want to overstay your welcome, but the fans are having fun and there's more story there. As long as we're allowed to keep doing it, Billy and I are in."
Zabka - who is an Academy Award nominated writer as well as actor - said the nostalgia for the film through an army of younger fans has been surreal.
"Karate Kid has sustained and grown in pop culture over the decades but there's a real feeling of the sprit of the '80s coming back - music and fashion," he said.
"My own kids love it. It's cool to be a part of that resurgence.
"I'd definitely like to write for the show too. But we have our heads pretty full with being in front of the camera. But at the right time, it's definitely a possibility."
Macchio also revealed that some of the footage from The Karate Kid used in the very first episode of Cobra Kai was never actually used in the original movie - because there were so many takes of the famous crane kick.
"We did so many takes," he said. "From a bunch of different angles. Lots of those angles are in episode one of Cobra Kai that weren't even in the film.
"We did it over my shoulder, over Billy's shoulder. One time I was standing on a ladder dangling my leg out to shoot it in slow motion.
"But at the end of all that, they just used the one wide shot. The kick heard around the world!
"I did my bit but Billy takes the awesome hit and without that, the scene wouldn't have worked."
Cobra Kai season three hits Netflix on January 1.