You can have just over a year to ask for a review if you have new, chiefly medical, evidence to offer. Your medical practitioner can submit that within a one-year period of your decision, but you have only 90 days to file an objection. Some of the people who were denied back in May, June or July are already well outside that window. You can cite special circumstances and ask for an extension of that 90-day period, but it's not clear how many of those are going—
On October 4th, 2018. See this statement in context.