Under the Federal Employees Health Benefits Program, generally there are no waiting periods for coverage. Upon enrollment, employees and their eligible family members typically start receiving health benefits immediately, provided that the employee is in a pay status and has completed the necessary enrollment procedures. However, it is essential to be aware that there can be different rules regarding specific plans offered under FEHBP. Some health insurance carriers may have their own policies regarding pre-existing conditions, which can affect coverage for certain medical issues that existed prior to enrollment. Additionally, there may be variations depending on the type of plan selected. It is advisable for individuals to review the specific plan details and benefit summaries available on the FEHBP website to gain a comprehensive understanding of any potential waiting periods or other requirements specific to their chosen plan.