This week he will jump up two age groups when he debuts with the U19 team at the FIBA World Championship in Prague, Czech Republic.
The 6-foot-10 Okafor and his teammates will debut Thursday against the Ivory Coast.
"We've only won the gold medal twice for the 19U [since 1991]," Okafor, who turned 17 in December, said Thursday after a practice at the Verizon Center.
"I won the gold medal for 16s and 17s so I'm undefeated and I plan on doing the same thing."
While some incoming college freshman are not on the U19 team -- most notably Duke's Jabari Parker and Kentucky's Julius Randle, the latter of whom played with the gold-medal winning U18 team last summer -- Okafor said he didn't hesitate when invited to try out.
He was the MVP of the 17U gold-medal winning team a year ago.
"I actually knew it was something I would like to do," Okafor said. "I knew it would be a challenge for me. I heard the coaching staff that would be a part of it and all the players that would be here and I want to get better, so I didn't even hesitate to say yes."
Asked if he tried to get Parker, a fellow Chicagoan to join him, Okafor said, "No, Jabari has his own mind."
In fairness to players like Parker, Randle and Canadian Andrew Wiggins -- who is not with his U19 team, either -- those players are getting accustomed to college life this summer.
With the exception of Washington-bound point guard Nigel Williams-Goss and Arizona-bound forward Aaron Gordon, every player on the U19 roster is either a rising college sophomore or junior or, in the case of Okafor and Houston St. John's wing Justise Winslow, a rising high school senior.
Okafor is the subject of a heated recruiting scenario that has been well-documented here.
He has cut his list to eight schools and he and Minnesota point guard Tyus Jones are planning on playing together in college. They also want Winslow to join them, but he said he's not certain if it will work out. It has been speculated that at least two of them could land at Duke, although Okafor said no decision has been made.
Right now, Okafor's only planned official visit is to Baylor in late August, with Jones.
Asked if he had any other visits planned, Okafor said, "I'm not really sure yet, I haven't decided."
After the World Championship, Okafor hopes to potentially make the last day of the LeBron James Skills Academy in Las Vegas on July 9.
He plans to go from there to the Nike Peach Jam July 10-14 with his Mac Irvin Fire club.
"I have to win Peach Jam before I quit playing AAU," Okafor said.
After that, he heads to Las Vegas for the AAU circuit and will play later this summer in the Adidas Nations event in Los Angeles.
For the next two weeks, he is expected to be a major part of the U19 team despite being a high schooler.
"Jahlil [has the] ability to actually have a guy we can throw the ball inside to and he can score," U19 coach Billy Donovan told SNY.tv. "[Jarnell] Stokes has been in college for two eyars, but Jahlil's probably got a little more size and length than he does."
Said Tennessee's Stokes of Okafor: “He’s one of the best scorers as far as his size in the post. He’s a very talented player. He’ll be really good when he matures.”
Okafor hopes to show his talents over the next two weeks, and then to capture his third straight gold medal to cap it all off.
**For more coverage of the USA U19 and U16 teams, click here.