This report consists of an article from the December 1979 issues of the Monthly Labor Review, an explanatory note, and supplementary tables. The article considers these factors which determine the length of time a person works continuously for the same employer: age and sex, marital status of women, race, and occupation and industry. It is shown that workers under age 25 change occupations most frequently; single women generally remain in the same job longer; white men had worked longer on their current jobs than black men, but black women had worked longer than white women; and farmers had the longest job tenure of any occupational group, and workers in the construction and trade industries had the shortest. The explanatory note briefly describes the basic labor force concepts, sample design, estimating methods, and reliability of the data used in the report and based on a question in the January 1978 Current Population Survey. Supplementary tables include tenure on current job by (1) sex, (2) age and sex, (3) full-time or part-time status and age (marital status of female workers), (4) class of worker (industry of men), (5) class of worker (industry of women), (6) occupation of men, (7) occupation of women, and (8) age and sex (years of school completed). (YLB)