The American Community Survey (ACS) has not in the past, and does not currently, use a finite population correction (FPC) factor in its variance estimation methodology. However, the Census 2000 long form variance estimation methodology did include such a factor. One-year ACS samples are not large enough for an FPC to have much impact on variances. However, with 5-year ACS estimates, up to 50 percent of housing units in certain blocks may have been in sample over the 5-year period. Applying an FPC factor will enable us to get a more accurate estimate of the variance, particularly for small areas. Research began on assessing the feasibility and the magnitude of the effect of incorporating an FPC factor into ACS variance estimates.