Hopewell (1997) called for greater attention by financial planners to uncertainty. This paper provides a unique approach to dealing with the uncertainty of projecting stock accumulations. The standard approach is to take mean rates of return in projecting portfolio growth, with perhaps a separate discussion of the range of possible rates of return (e.g., Mittra, 1995, p. 394). This paper provides a mean/worst case approach that can be made understandable to clients. For accumulation projections with a horizons of 10-15 years, the worst case projections might be intimidating, as the worst case accumulations are less than 30% of the mean accumulation for most horizons. However, the worst case projections may serve to adequately inform clients of the range of possible outcomes.