Answer:
Larger possums such as brushtail and ringtail possums can live up to 11 years if not taken by predators or hit by cars. They tend to have an average lifespan of 6-7 years.
Sometimes it depends on whether the possum is male or female.
For smaller species such as the Eastern Pygmy Possum, it varies hugely for males and females. Females average 11 years, but males usually only live to four years.
Virginia opossums, which are quite different to true possums, appear to have a maximum lifespan of four years, even in protective captivity. In the wild they are more likely to live only 1-2 years.