Mergers and acquisitions (M&A) are transactions in which the ownership of companies, other business organizations or their operating units are transferred or combined. M&A is an extremely important concept in the world of retirement plans. Whether a business transaction is a merger, the sale of stock or sale of assets will have a tremendous effect on the retirement savings of plan participants if the acquired company and/or acquirer sponsor retirement plans. A plan sponsor who is either acquiring a company or its assets or finds itself to be a target for purchase needs to understand some important concepts when it comes to 401(k) plans. This article will bring up some important considerations as it pertains to M&A and 401(k) plans.