Optional coverage refers to insurance policies or benefits that are not required, but can be added onto an existing policy for additional cost. This means that while you may have a basic level of coverage through your employer's health plan or other insurance provider, you also have the option to purchase additional coverage if you want more comprehensive protection. Examples of optional coverage include dental and vision plans, disability insurance, critical illness coverage, and accident insurance. These policies are not mandatory but can provide extra financial security in case of unexpected medical expenses or other events.