Target date retirement funds, which have become the default investment option in most 401(k) plans, are facing renewed criticism for their one-size-fits-all approach to asset allocation. Critics argue that these funds fail to account for individual circumstances such as pension income, spousal retirement savings, and real estate wealth.

Research published this month found that workers with identical target retirement dates but vastly different financial profiles are often invested in the same fund, leading to suboptimal outcomes for many. A worker with a generous pension, for example, could afford more equity exposure than the fund's glide path provides.

Fund providers are beginning to explore personalized target date solutions that adjust allocations based on participants' broader financial pictures. In the meantime, financial advisors recommend that retirement savers periodically evaluate whether their target date fund aligns with their complete financial situation rather than blindly accepting the default.