We study optimal portfolios for defined contribution (possibly mandatory) pension systems, which maximize expected pensions subject to a risk level. By explicitly considering the present value of future individual contributions and changing the risk-return numeraire to future pension units we obtain interesting insights, consistent with the literature, in a simpler context. Results naturally imply that the local indexed (inflation-adjusted) currency is the benchmark and that the investment horizon is long. Optimal portfolios have a hedging component with an even longer duration than a deferred (real) pension, which begins its lifetime payments upon retirement. Results are illustrated with the parameters obtained for the United States by Campbell and Viceira (2001).