Race Directors can now allow Deferred Entries. This allows runners who might get injured or have a conflict to defer their entry until the following year.
Like other Participant Management features like bib exchange, event transfer, refunds, you can set an additional cost for this service as well as a cut-off date. You set this up in the Customize -> Participant Management section as shown on the right.
Once you renew your race for next year, just run the deferred entries report on the Financial page and import those deferred entries.
Runners can easily defer their entry by logging in and clicking on their Profile.