<prompt> Human: Some BackgroundHere at rpersonalfinance, we talk a lot about the costs of investing. Most of the focus is, rightfully so, focused on the cost incurred by the employees in their Defined Contribution plan. However, theres not a lot of discussion, or even data for the matter, on how much it costs employers to run a Defined Contribution plan.Recently, I received a letter in the mail from my employers 401k plan administrator going over some changes to the plan. One of the changes was the addition of a 0.25 wrap fee added to all investments boo. They did change share classes for many of the mutual funds and CITs available, and based on previous data I had put together, total employee costs were down about 8, but now about half of the plans administration expenses were put on employees.This got me thinking: how much is the average cost, per employee, for companies to pay for defined benefit plan administration? Could I use this data to convince my employer that they were paying too much, even after shifting some of the expenses off on employees?I set out and collected some limited data from individual company Form 5500 filings. For those of you who are unaware, Form 5500 is a filing every defined contribution plan has to have filed every year that contains the number of plan participants, total assets, and total administration expenses that the plan incurs. Initially, I used the individual form retrieval tool, but I soon found out thanks unickaggie! that the entire Form 5500 dataset was also available on the Department of Labor website in CSV format.I quickly got to work, sorting through the data with a combination of SQL and LibreOffice Calc to generate some statistics. I wont go over the details of how here, but perhaps in a reply.The ResultsBelow is an overall view sample of the data I processed. All numbers listed are plan costs per employee, as reported on the Department of Labor Form 5500 and related Schedules for plan years ending in 2012. Companies reporting partial plan years were not included.Feel free to share any of the visuals; Ive put a CC-BY notice on them so that they cant be published by others without attribution.Imgur Gallery Containing All Result PlotsNote: If you want a graphic of some specific data subset, leave a comment below, and Ill get to it later.Overall Plan DataMean - 65.37Median - 19.5575th Percentile - 64.4925th Percentile - 5.63Standard Deviation - 555.53---Low Balance Plans Plan Assets Under 5MMMean - 64.96Median - 16.4575th Percentile - 54.1525th Percentile - 4.26Standard Deviation - 852.88---Mega Plans Plan Assets Over 1BMean - 73.94Median - 27.9175th Percentile - 85.7625th Percentile - 5.57Standard Deviation - 158.54---Small Company Plans Under 100 Employees ParticipatingMean - 453.10Median - 45.9575th Percentile - 158.2825th Percentile - 10.05Standard Deviation - 3,279.98---Medium Company Plans 100-999 Employees ParticipatingMean - 58.35Median - 20.4375th Percentile - 69.1225th Percentile - 5.75Standard Deviation - 122.32---Large Company Plans 1000-9999 Employees ParticipatingMean - 33.56Median - 15.0075th Percentile - 39.5725th Percentile - 4.87Standard Deviation - 67.74---Huge Company Plans 10000 Employees ParticipatingMean - 29.15Median - 11.8275th Percentile - 33.4525th Percentile - 3.87Standard Deviation - 48.28---Some Curiosities and SpeculationFrom the data, its clear that 401k plan administration expenses are the most consistent when there are a large amount of participants in the plan. Small employers are subject to the widest fee range.Many companies have 0 overall plan expenses. With the amount of work that regulatory filings are, clearly these providers arent giving companies a free lunch, so employees must pay for plan administration expenses. Additionally, its likely that many companies throughout the dataset arent paying for plan administration expenses solely out of their own pocket. I estimate my employer is slated to pay about 200employee, with employees paying on average 200 per year for plan administration expenses.Some companies had negative plan expenses. I presume that this is the result of plan administration expenses being paid out of revenue sharing, and somehow the revenue sharing overwhelmed the costs of plan administration, so the company or the plan got a refund.---Raw DataCSV Containing minimal dataset required to generate these statistics - 6.6 MB Google Drive DownloadSQLite database containing all Form 5500 base form, Schedule H, and Schedule R Data - 210MB Google Drive DownloadDepartment of Labor website containing all the above data in compressed CSV format - Department of Labor Website---ConclusionI hope this data is useful andor interesting. I personally hope that I can use this data to convince my employer to shop around for other 401k plans based solely on their costs alone. Perhaps there are others in a similar position who can use this data as part of their campaign for improving their employers 401k plan.  <response>: I dont really have anything to add, but Id like to say thanks for taking the time to do some analysis and make the data available! 