Your Last Will and Testament or Trust will determine who inherit your assets. However, the innocent situation arises in many cases where those other assets-like life insurance, POD accounts, retirement accounts, or jointly owned assets-pass outside and irrespective of your testamentary documents. This can potentially seriously disrupt your estate plan and create several issues such as questions on the payment of estate/inheritance taxes on those transfers, insufficient assets in the estate to pay administration/funeral costs.
Estate planning is more than just drafting and signing a will and trust. It is a comprehensive review of the financial situation and the assets and how those assets are owned. Your planner should guide and assist you with this review. Remember: how those assets are owned will dictate who owns them in the end.