The singers will take over from Christina Aguilera and Cee Lo Green on the talent show's spring 2013 run.
However, the two original coaches are expected to return for the fall 2013 cycle, as part of a plan to build a wider pool of mentors that can interchange in future seasons.
"Having award-winning artists as coaches means they need to be able to tour," said executive producer Mark Burnett.
"Whether in the red chair or on tour, our coaches have their chairs for life. This is exactly why, after three seasons, we needed to allow them to rotate out so they can get on the road amongst their fans.
"Meanwhile, we're incredibly excited to have singular artists like Usher and Shakira joining the fold."
Aguilera is currently building up to the release of her seventh studio album Lotus, which is due out November 12 in the UK and a day later in the US.
"Since this year NBC and The Voice have decided to tape back-to-back seasons, requiring a full-year commitment, it is important for me to take season four off, allowing me to support my music that my fans have been waiting for," the 'Your Body' singer explained.
"By pursuing my first passion of music during the break, I am also able to come back and offer even more to my team on The Voice in the future."
Meanwhile, Cee Lo has a number of musical projects in the works, including his first Christmas album Magic Moment, the Goodie Mob LP and his Las Vegas residency 'Loberace', while he is also developing a sitcom based on his life for NBC.
"It's great to also give a host of other talent the chance to experience what a joy it is to be part of what is truly the best show of them all, The Voice," Cee Lo said.
"I will return for season five and will be watching season four. NBC is home and as far as Usher and Shakira are concerned - 'mi casa su casa'."
The Voice continues tonight (Monday, September 18) at 8pm ET on NBC.
Watch a promo for the current season of The Voice below: