Fifteen years ago today, on May 6, 2006, Carrie Underwood became a college graduate. The singer graduated from Northeastern State University magna cum laude, with a Bachelor of Arts degree in mass communications and an emphasis in journalism.

Underwood was only three credits away from earning her degree when she withdrew to participate in Season 4 of American Idol. The now-country superstar was crowned that season's Idol winner on May 25, 2005, and thanks to all of her time on TV, NSU gave Underwood those final three credits.

“I’ve obviously done enough with television,” she told People at the time. “There was my internship right there!”

Underwood had just kicked off her first tour when she returned to Oklahoma to participate in her graduation ceremony; however, she declined to do any interviews the day of the event, so that she wouldn't receive more attention than the other graduates.

While in college, Underwood was a member of the Sigma Sigma Sigma sorority. She spent two summers performing at the college's Downtown Country show in Tahlequah, Okla., and became the Miss NSU runner-up in 2004. Underwood also met a now-familiar face at Northeastern State University: Zach Swon from the Swon Brothers. The two were in a show together, and they also both took a country music theater class.

Underwood never got a chance to use her degree -- at least not in a professional capacity. After winning American Idol, she released her debut album, Some Hearts, which included the multi-platinum No. 1 hits "Jesus, Take the Wheel" and "Before He Cheats," and ... well, you know the rest.

The year 2006 was a big one for the then-rising star: In addition to getting her college degree, Underwood also received her first two ACM Awards and her first two CMA Awards.

WATCH: Unforgettable Carrie Underwood Moments

LOOK: Carrie Underwood + More Country Stars Who Learned Before They Earned

More From KEAN 105