To be clear, professional liability insurers (which write policies on a claims-made or a claims-made-and-reported basis) do not typically provide coverage for claims that are foreseeable at the time of transition and, therefore, there can be gaps in coverage even where back-to-back policies are in place.

This is a different result than when dealing with occurrence policies (like auto, homeowners or other general liability policies) which do not contain such prior knowledge provisions (that can be embodied in the insuring agreements or in the exclusions).