The contract does not include a player or team option, per Shams Charania of The Athletic and Stadium.
ESPN's Bobby Marks provided a yearly breakdown of the deal, which will pay Siakam $129.9 million in total:
Siakam was a first-round pick in 2016, and the 2019-20 season would have marked the final year of his rookie contract.
He is coming off a breakout performance in 2018-19 that resulted in him being named the Most Improved Player. After averaging 6.0 points during his first two years in the league, he averaged a career-high 16.9 points and 6.9 rebounds per game last season.
As good as he was during the regular season, he upped his game even more while helping the Raptors win their first-ever championship.
He put up 19.0 points and 7.1 rebounds per game during the postseason run, recording 19.8 PPG and 7.5 RPG during a six-game victory over the two-time defending champion Golden State Warriors in the 2019 NBA Finals.
Josh Lewenberg of TSN reported in late September that the two sides had engaged in preliminary extension talks, with Siakam's camp seeking a max contract worth approximately $130 million over four years. At that time, though, a deal did not appear to be close.
Ultimately, they were able to come to an agreement that will keep Siakam in the Six through the 2023-24 season.