The German-born Nowitzki told Brad Townsend of the Dallas Morning News that he and his wife, Jessica, are working on getting their green cards:
"We're in the process of getting a green card. So once we accomplish that, then you have to be a green-card holder for, I think, over five years before you can even think about doing that [becoming a U.S. citizen]. So we're going to do that and see how it goes. But obviously our [three] kids were born here and they all have U.S. passports and the wifey and I have been on a visa for the last few years.
"So hopefully that's going to be accomplished soon."
Nowitzki did not come over to the United States until he was 20 years old after being taken ninth overall in the 1998 NBA draft. He would go on to spend his entire career in Dallas, and his 21 seasons with the Mavericks were the most a player has spent with one franchise in league history.
Back in January 2012, Nowitzki mentioned the possibility that he would consider applying for U.S. citizenship upon retirement.
"Yeah, if I stay in the States, it would probably make sense," Nowitzki told SportsDay in 2012. "I'd have to see what my situation is, but it's something I'd look at."
The 40-year-old did not officially announce his retirement until April. While he would no longer be suiting up for Dallas moving forward, he let it be known that he considered himself a "Texan for life":
And almost immediately upon retirement, he has gotten the process started. He will be able to apply for full citizenship five years after he receives his green card.
According to TMZ Sports, Nowitzki will be looking to obtain dual-citizenship, as he is not looking to give up his German citizenship.