Reconsideration has been eliminated in some states. Your denial will state if your appeal will be for Reconsideration or for a hearing before an ALJ.
While you need to get your appeal in a timely fashion, generally 65 days from the date of the denial letter, you also will need time to gather new medical evidence. This link has a very good explanation of how to most effectively examine your denial letter and how to prepare your response:
http://www.hcvadvocate.org/hepatitis...ideration.html