Starting a new job in October. My current employer says that my current health insurance coverage ends on the last day of the month in which I terminate employment (so Oct 31). My new employer's health coverage starts from my start date (mid Oct). Does this mean I have overlapping health insurance coverage for the ~2 weeks at the end of October? Can I legally submit reimbursement to both companies for medical expenses incurred during the overlap? If no, then which is "primary"?