The National Household Education Survey (NHES) is a data collection system of the National Center for Education Statistics (NCES) designed to address a wide range of education-related issues. It is a telephone survey of the noninstitutionalized civilian population. This working paper presents information on the potential for undercoverage bias in estimates from the 1995 NHES. Estimates from the 1995 NHES are subject to bias because only households with telephones were sampled. Data from the 1992 October supplement to the Current Population Survey of the U.S. Census are used to evaluate the potential size of the bias of the estimates. The focus in the report is on the statistics for two separate populations: 0- to 2-year-olds who were sampled as part of the Early Childhood Program Participation (ECPP) component and civilian adults who were sampled for the Adult Education (AE) component. The analysis of undercoverage bias shows that the coverage biases for estimates of adult characteristics are not very large, but biases for 0- to 2-year-olds are somewhat larger, yet still relatively small. The coverage bias is small even though some of the differences in characteristics for persons living in telephone and nontelephone households are large. The undercoverage bias for subgroups in the NHES may be more of a problem. In this study, the undercoverage biases for characteristics of Black and Hispanic American 0- to 2-year-olds were generally larger than for all children. For adults, these undercoverage biases were not as large as for children. Overall, however, results support the use of the telephone survey methodology. An appendix presents three tables of study data. (Contains nine references.) (SLD)