Being a retirement plan fiduciary such as a plan sponsor or a plan trustee is like being a homeowner. Homeowners see their homes as a serious financial accomplishment and an important investment. Homeowners are unaware of the hidden liability pitfalls that homeownership entails, like lawsuits for those injured on their property or the liability to trespassers who are injured because of an attractive nuisance like a swimming pool. The same can be said of a plan sponsor or a plan trustee that is unaware of the hidden liability in their roles as plan sponsors. Retirement plan sponsors have important responsibilities and are subject to standards of conduct because they act on behalf of participants in a retirement plan and their beneficiaries. These responsibilities include: acting solely in the interest of plan participants and with the exclusive purpose of providing benefits to them; carrying out their duties prudently; following the plan documents; diversifying plan investments; and paying only reasonable plan expenses. While these duties seem pretty straightforward, there are certain instances where a plan sponsor is unaware that their action or inaction puts them at risk to liability from either plan participants or governmental agencies such as the Department of Labor (DOL) and the Internal Revenue Service (IRS). For plan trustees, that liability may be personal liability. This article details pitfalls that plan sponsors are usually unaware of, that exposes them to potential fiduciary liability.