Can you be denied health insurance based on the kind of medicine you are prescribed?

This can vary between individual companies. I write applications for BlueCross BlueShield of Florida and we have a list of about 15 medications that will render the applicant ineligible to complete the application process. Mostly diabetic, heart, and mental illness medications. However, in January of 2009 the applicant will be eligible for a new limited benefits plan under the "Cover Florida" program.