Lewis was reported to have a signed a five-year contract with the Showtime drama earlier this year.
"I'm signed for seven seasons," he clarified, in an interview with Entertainment Weekly. "But that doesn't mean anything. You know that. They can kill me whenever they want."
He continued: "Maybe they'll kill him off [in the season two finale]. They could tell an entirely new story next year. Maybe that's what they want to do."
Lewis promised that the Homeland finale - which airs this Sunday (December 16) in the US and a week later on Channel 4 in the UK - will be "an emotional, nuanced, character piece".
"I think [the finale] is going to be an incredible episode," he said. "Everyone seems extremely happy with it. I haven't seen it yet, so I'll be sitting down with you guys and watching it.
"I thought last season's ending was incredible - and most people adored it - but there were one or two people who might have wanted something different. So hopefully we'll be able to please most of the people."
Homeland was recently nominated for three Screen Actors Guild Awards, with Lewis being recognised in the category of 'Drama Actor'.
> Damian Lewis on 'Homeland' future: 'Brody could die'
> 'Homeland's David Harewood: 'People think Estes is a baddie'
Watch a clip from Homeland below: