A good insurance broker will very seldom submit a clients application for underwriting without being relatively certain that they will be covered. We called this field underwriting, end it is just what it sounds like: As an agent, I know your companies' underwriting guidelines and I know the right company to sub,it the application to. (That's why you're asked such invasive questions during our initial fact-finding conversations!)
Life isn't always perfect though, and sometimes we missed something in the field that underwriters in the home office will latch onto and decline you for. Typically, this is something as simple as a client forgetting that they were on a medication several years ago and not disclosing that. When the underwriting department at the insurance company pulls your medical records, they will find it even if you have no recollection whatsoever of that event. These things happen though, and there are always alternatives if you find yourself in a position where your application for coverage is denied.