Less than three years after Congress sanctioned target-date funds as appropriate default investments for US workers’ retirement savings, prolonged market turmoil has led lawmakers and critics to scrutinise the products’ suitability anew.

As elected officials and others call for regulators to examine this slice of the retirement savings market, the industry has responded. Some fund companies have altered asset allocations to allow for a greater cushion against market losses, while others have taken steps to more closely follow indices and cut fees.