Time varies from 30 days to about 2 years or more that I’ve seen but there is no absolute time period. If your claim is for a terminal condition you’ll probably be approved in 30 days. If it goes to the second phase it may be approved or denied in 6-12 months. In some cases 4 months but I wouldn’t count on it.
If the claim goes before an administration law judge your chances for approval have gone down substantially and can take a year or more. Usually helps to have an attorney. Good luck!!!