The birthday girl wore a Versace black dress with a Tyler Ellis clutch as she and her 30-year-old husband walked the Nashville, Tennessee, red carpet. Right after posing for the cameras, Lambert opened the show, which was hosted by Luke Bryan, from Bridgestone Arena.
"I'm opening this year, so that's a little scary," Lambert told ET ahead of the ceremony, before quipping, "It's a little scary, but that means by 7:05 I can drink."
"It is a special one," she added. "We worked on it for a while. It's got some sass to it for sure. There will be fringe involved... Maybe some glitter."
Lambert will be waiting to see if she's able to nab one or more of the three awards she's nominated for: Entertainer of the Year, Female Vocalist of the Year and Musical Event of the Year.
"It's a big deal," she told ET of her nominations. "I mean, I've been coming to the CMAs since 2005, and every time I'm still just as nervous and excited to be there. It's a great night. It's a night just to celebrate your peers, your friends, and country music. So getting to be part of it all this time is a blessing for sure."
With her three nods this year, Lambert remains the most-nominated female artist of all time and the third most-nominated person in the show's history, with a total of 58 nods.
"When those kind of accolades get in my mind I'm like, 'What just happened?'" Lambert admitted. "It feels like some days I just started... but it also puts a fire under my butt to keep reinventing, and doing more."
As for how she'll continue her birthday celebrations after the show, Lambert told ET, "I'm hoping to celebrate over tacos, margaritas and casserole... Pretty sure the thing I'm gonna do is put on a sweat suit and eat a taco. That's a happy birthday to me."
Earlier in the day, the singer's husband posted a sweet birthday tribute, writing, "This world became such a better place with you in it. You are a light for those in the dark, a voice for the ones who can’t be heard and most important of all, you’re the most amazing wife day in and day out. I hope today brings you as much joy as you bring to me daily. Happiest of birthdays @mirandalambert ❤️❤️ I love you 🥳🥳."