A fundamental question in aging research is whether humans and other specie
s possess an immutable life-span limit. We examined the maximum age at deat
h in Sweden, which rose from about 101 years during the 1860s to about 108
years during the 1990s. The pace of increase was 0.44 years per decade befo
re 1969 but accelerated to 1.11 years per decade after that date. More than
70 percent of the rise in the maximum age at death from 1861 to 1999 is at
tributable to reductions in death rates above age 70. The rest are due to i
ncreased numbers of survivors to old age (both larger birth cohorts and inc
reased survivorship from infancy to age 70). The more rapid rise in the max
imum age since 1969 is due to the faster pace of old-age mortality decline
during recent decades.