No, not always. Countries have the option of submitting a song or withdrawing from the contest on a year-by-year basis, if they so wish. For the 2021 contest, countries including Montenegro, Bosnia and Herzegovina and Armenia will not be returning. However, both Bulgaria and Ukraine are returning after being absent at the 2019 contest. Furthermore, Belarus did not submit a song that adheres to the guidelines in time, meaning that it is not competing in 2021.