Works published in English elsewhere in the world are also eligible, provided they are released on either a website or in an electronic edition.
Each year, works are nominated by SFWA members during a period typically spanning from December 15 to January 31.
The six works receiving the most nominations proceed to the final ballot, with additional nominees considered in the event of ties.
Subsequently, members have about a month to vote on the final ballot, and the winners are announced at the Nebula Awards ceremony held in May.
Silverberg's and Kress's eight nominations are the most of any authors, followed by Lucius Shepard and Michael Bishop at seven, and Kate Wilhelm and Avram Davidson with six.