This paper develops a methodology for constructing confidence intervals around postcensal state population estimates. Using regression equations, forecast intervals are derived around the average age-specific death rates over the postcensal estimation period. These results, combined with the number of postcensal deaths and the most current census counts, are translated into confidence intervals for the age structure. Two approaches are offered for constructing total population confidence intervals. One examines a simulated distribution while the other focuses on the mathematical derivation of population means and variances. The methodology is illustrated by deriving statistically defensible confidence intervals around the July 1, 1975 population of Florida.