fairly recent; definitely not older than the target site
it is no longer possible for regular users or diamond moderators to migrate questions that are more than 60 days old
Questions that are off-topic but do not satisfy the other criteria should be closed as off-topic and not migrated.
Make the migration happen.
Five regular users of any site who have the close privilege may vote to migrate questions away from that site. Possible destinations are limited to the site's meta and sites that have historically been popular migration targets. Three close voters must agree on a target site for a migration to succeed (four on Stack Overflow).
Every site has diamond moderators who can migrate questions to any other site in the network at will. You can flag candidates for moderator attention using the "other" reason, and explain why/where they should be migrated using the free text box. This is the only way to migrate a question to a site not in the short list, and can also be useful on less active sites.