The deal means that the British actor could potentially play the role of Nicholas Brody for seven seasons total, according to the Daily Mail.
Homeland co-star David Harewood - who plays CIA counter-terrorism director David Estes - has apparently signed a similar five-year deal.
Lewis recently won an Emmy in the category of ''Outstanding Lead Actor' for his performance as tortured marine-turned-politician Brody. Homeland itself was also named 'Outstanding Drama Series', while Claire Danes (Carrie Mathison) was recognised as 'Outstanding Lead Actress'.
The second season of Homeland is currently airing on Showtime in the US and Channel 4 in the UK, with a third run yet to be officially confirmed.
Photo gallery - Homeland season 2 episode 2:
Copyright: ShowtimeEarlier this year, David Harewood told Digital Spy that he feels the series should only run for "four or five years".
"As long as we don't end up doing stuff that is way too far-fetched, I think [a run of that length would] be great," said the star.
> Homeland episode two 'Beirut Is Back' - new pictures
> Homeland boss: 'Brody could die in season two'
Watch Damian Lewis talk Homeland season two below: