Using administrative data, we examine the fund design and efficiency of the South African retirement fund industry over the period 1996–2018. Like many other countries, the retirement fund industry in South Africa is dominated by defined contribution funds. Total assets per member have been declining for defined benefit funds, which are now dominated by unclaimed benefit members. We find that South African retirement funds are not operating at an efficient scale. There are strong significant economies of scale present in the industry, with total administrative costs increasing by only 72% when the total number of fund members doubles. Preservation funds and retirement annuities are found to be most efficient and operating at an efficient scale. None of the benefit structures are operating efficiently but hybrid funds are the most efficient.