The extension is for $75 million in new money -- bringing the total value of Kamara's contract to $77.133 million -- and includes $34.333 million guaranteed, sources told ESPN's Adam Schefter.
The average annual value of the extension, $15 million, matches what Ezekiel Elliott signed for with the Dallas Cowboys in 2019 and trails only Christian McCaffrey's $16 million per year with the Carolina Panthers.
Although negotiations got tense late in training camp, when Kamara was an unexcused absence for four days and a source confirmed that the Saints were open to the possibility of trading him, the two sides ultimately found middle ground heading into the final year of his rookie contract.
Now the Saints are close to securing a huge part of their offense for the second year in a row after signing wide receiver Michael Thomas to a long-term extension last summer.
Kamara, 25, was the NFL's Offensive Rookie of the Year in 2017 after being drafted in the third round out of Tennessee. He has been one of the league's most dynamic dual threats as a runner and receiver, with a total of 2,408 rushing yards, 2,068 receiving yards and 38 touchdowns. His 4,476 yards from scrimmage are the fifth most in the league since 2017.
He is just one of four players in NFL history to surpass 2,000 yards rushing and receiving in his first three seasons -- joining McCaffrey, Herschel Walker and Roger Craig, according to ESPN Stats & Information.
While Kamara's numbers have been among the best in NFL history to start a career, his yards per touch have gone down in each of the past two seasons -- from second in 2017 (7.7 yards) to 18th last season (5.3 yards), according to ESPN Stats & Information.
He had exactly 81 catches in each of his first three seasons, despite missing two games last year and being hampered by knee and ankle injuries over the final half of the season. The 243 receptions through three seasons are second only to McCaffrey's 303 in NFL history, according to ESPN Stats & Information.
The extra value that Kamara brings in the receiving game made the Saints feel better about investing in him long term, despite the daunting salary-cap situation they are about to face in 2021 and beyond.
Prior to Saturday's deal, the Saints had less than $6 million in cap space this year and were already projected to have more than $240 million in cap costs for 2021, when the cap could drop as low as $175 million per team.
Furthermore, they are nearing the ends of contracts with fellow standouts like linebacker Demario Davis, cornerback Marshon Lattimore, offensive tackles Ryan Ramczyk and Terron Armstead and safety Marcus Williams.