Carolyn Kaster/AP Images

MIAMI — President Barack Obama has called upon LeBron James to come through in the clutch.

The president's signature initiative, the Affordable Care Act, is facing a critical deadline, as open enrollment into the marketplaces on HealthCare.gov is scheduled to end on March 31. In a race to beat the buzzer, the Centers for Medicare & Medicaid Services (CMS) have been enlisting celebrities popular with young adults, including several in sports, to raise awareness and promote the merits of signing up.

No current athlete has more clout with that demographic than James, as evidenced by his ability to sell everything from basketball shoes to smartphones.

So Obama recently contacted the Miami Heat forward and requested his assistance, offering a number of different ways James could contribute.

"Any way I can help the president, that's pretty cool," James said Wednesday night.

Bleacher Report has learned the form that help will take: a 30-second public service announcement, released in time for March Madness, in which the four-time MVP speaks about the importance of health care coverage. It is similar in style to the television spots featuring former NBA stars Magic Johnson and Alonzo Mourning, each of whom has dealt with a serious health issue—HIV for Johnson and kidney disease for Mourning.

James' spot will air on many outlets, such as ESPN, ABC, TNT and NBA TV, during NBA games. It will also air during local sports programming in markets with a high concentration of uninsured people.

While Johnson and Mourning are retired and 54 and 44, respectively, James is in his prime at 29, making him a more ideal pitchman to the target audience. He's also long been a strong Obama supporter, even prior to the former Illinois senator's election as president. Their relationship has grown into a friendship through a series of events (a basketball game for Obama's 49th birthday in 2010, visits with the champion Heat in 2013 and 2014) and conversations.

According to an administration official, "The president greatly admires and respects LeBron, and we are excited that he is joining a number of other athletes in helping spread the word during these critical final weeks of open enrollment."

James welcomed the chance to communicate, collaborate and advocate—to speak to young adults who might not be "knowledgeable about health care and are also kind of waiting until the last minute" to sign up.

"It's almost like car insurance," James said. "You want to put yourself in a position where—you hope you never get into an accident—but if you do, you want to be secure. And I think a lot of young adults and African-Americans as well are afraid because they are not even educated about it. And hopefully my voice, and hopefully the other people who've done it, can get them more knowledgeable about it."

Other prominent athletes—Michael Jordan, most notably—have avoided getting involved in social or political issues during their playing days. James, however, has shown a willingness to step out into the public square in recent years, as evidenced by his organization of a team photo in honor of slain teenager Trayvon Martin in 2012.

Few topics have been more controversial in some circles than what is commonly called Obamacare. James recognized the potential for some backlash, but it didn't dissuade him.

"I mean, I can't worry about that," James said. "Especially who I am. I mean, I know that everything that I do is going to be bigger than what it should be or blown out of proportion. But what I believe in and the people that I support is what it's all about. So I can sleep comfortably at night."

Ethan Skolnick covers the Heat for Bleacher Report.