This is usually very bad for the claim. You might want to have a serious heart-to-heart discussion with your doctor about why he is refusing to cooperate with you. It may be that he feels that you are not disabled. It may be that he feels he's not being paid for his time for filling out mounds of insurance company forms. You need to know where your doctor stands on the issue of disability before you apply for disability benefits. It is the kiss of death to a claim to have your doctor telling the insurance company that you are not disabled.