Seniority | The Sim Environment Sims 4 Guide, tips

Once you are through being a young adult and an adult, you will be able to have kids, achieve professional success or even fulfill your aspiration. After that, you turn into a senior. This includes certain limitations. The Sim cannot have children then. A very important piece of information - there is no retirement - the Sim can work until the death (and add to the family budget). You need to remember that seniors tend to be uncomfortable more often, e.g. due to strain.

In the Simiology panel ([Y]) you can view how long your Sim has lived, so far. When the green bar that indicates the last stage in his life, reaches the end, the only thing left for him to do is die.