One-stop shopping for 401(k) plans would allow your company’s trustees to select a Third Party Administrator (TPA) that is able to provide the full range of administrative, legal, and investment services. It would also seem that the ease of dealing with only one retirement advisor would have the added benefit of reducing plan administration cost. This construct seems to make sense on paper, but in reality, big box TPAs often administer 401(k) plans in ways that result in higher plan administration costs, conflicts of interest, dual loyalties, and a potential for increased liability to the plan sponsor.