Detailed demographic information on the characteristics of households and families in the United States is presented in this report. The new data in this year's report are based on the current population survey conducted in March of l981. Some highlights of the topics discussed include the following: (1) Nonfamily households accounted for 10.1 million of the 19.0 million increase in the total number of households since 1970; (2) The median age of householders in 1981 was 45.9 years, down 2.2 years from the 1970 level; (3) About 60 percent of all households in 1981 were maintained by persons who were married and living with their husbands or wives, compared with 71 percent in 1970; (4) The size of the average household has declined from 3.14 persons in 1970 to 2.73 persons in 1981; (5) About one out of every five households had a householder age 65 or older, according to both the 1981 and the 1970 survey; and (6) One-parent families accounted for 21 percent of the 31.6 million families with children in 1981, versus 11 percent of the 28.8 million families with children in 1970. Sampling variability, which may be relatively large for the smaller figures as well as for small differences between figures, is discussed in an appendix to the report. (RH)