Upon receiving a denial of an initial claim or reconsideration, there are 60 days (+5) to appeal (for reconsideration or hearing). Claimants miss the deadline for various reasons. All is not necessarily lost if there is a valid reason for having missed the deadline. If a valid reason is accompanied by a reasonable delay of time, there is a decent chance that the appeal will be allowed to go through. SSA requires a "Good Cause" statement/letter which your lawyer  can prepare detailing the reasons why.