The type of health insurance you have will greatly affect your rights.
Your Congress enacted laws that provide great protection to "insurance" offered through larger companies. Typically, larger companies do not have insurance; rather, they have something that seems like insurance but is really a "self-funded plan." If you are insured by a larger company, the odds are you do not have the same rights as if you were insured by a typical insurance plan.
If you have real insurance, then you have significantly more rights if your healthcare claims are denied. You can get double damages and attorney’s fees as well as damages for bad faith and punitive damages.