Assuming you are talking about a company retirement plan (e.g., 401k) the default investment option for your plan should be available from several sources of information: your enrollment materials, your company's Benefits department or plan administrator, your recordkeeper's website and your recordkeeper's telephone support line.
I assume you are asking to find out where contributions that are being deposited into your plan's account in the case of a plan sponsor (the Employer) having chosen to use "participant self-directed investment accounts" (probably in a 401k plan or another defined contribution plan like a profit sharing plan that is set up where each participant can make their own investment choices amoung a menu of fund choices). Normally, a plan that has participant self direction must make a choice of what to do with moneies that are put in a participant's account but the participant never told anyone what they wanted their investments money to be put in. So, the law requires each Plan Sponsor that sets up such a plan to choose a specific investment fund(s) that fits certain Department of Labor Guidlines. This is called the "QDIA" funding choice. Also by law, within 30 to 90 days before a plan year ends, the Plan is required to give you a "QDIA" Notice than would explain everything to you. So, if you want to find out about the default "QDIA" fund(s) choice, you should just either go to anyone who has some knowledge about the plan Notice requirements to the participants, or call the plans broker or investment advisor who is responsible for the investments of the plan and perhaps also responsible for the recordkeeping of each participant's account values, and they should be able to eith get that information for you or they can tell you who should be able to get that information for you. But remember two things: (1) If you are a participant in the plan, you are supposed to automaticcally get the information you want each year, and (2) Do Not make the mistake of thinking that just because the "QDIA" was chosen as the "default" investment that that is where you should invest your money. The purpose of the plan having a "QDIA" is for a completely different reason than if you are thinking that it was picked by someone as the best choice for anyone to make to invest their money in. I hope that all helps. Herbie Glass, Certified Pension Consultant, etc.