Why do annual tables in the app leave off the final year of the plan?

Wherever possible, Income Lab plans are based on monthly data: monthly cash flows, monthly expenses, and even plan length/longevity assumptions expressed in months. That means that a plan's length may not be an even number of years. It's not uncommon for a plan to be, say, 31 years and 4 months long. This approach keeps changes in plans over time smooth. As someone ages, Income Lab updates plan length to reflect new longevity expectations from a different age. If plans could only be a whole number of years, we'd see longer periods where things didn't change and then jumps of a year or two.

However, in many of Income Lab's annual views, only full calendar years are shown. This includes Life Hub, Tax Lab, and many of the annual tables available under graphs (Income Sourcing, Expense Details, Taxes). The reason for this is twofold:

1. Partial-year totals can be alarmingly different from those in the final full calendar year of a plan. This can lead to confusion and questions from clients. Furthermore, having a plan stop in, say, February (and so showing only 2 months' worth of values) draws unnecessary attention to “end of plan”/"end of life" themes that may not be the focus when you are reviewing numbers with a client. Leaving partial final years off of annual tables avoids this distraction.
2. Taxes are a full-calendar-year concept. And so, doing taxes on a partial year may be misleading. It's true that if someone dies mid-year and is the last to die in the couple, the final year's tax return will be quite different from a full-year return. But the goal of an Income Lab plan is not to communicate that we know exactly when someone will die. That level of precision in tax estimates is misleading and implies that we do know when the end of life will hit. Therefore, we don't include tax estimates for final partial years in the plan.

Note that in the Social Security Optimizer, you will see final partial-year totals when looking at the details of a particular strategy. The reason for this exception is that this view is often used to analyze and understand Social Security benefits in depth. If the final year includes an important change (such as a switch to survivor benefits), we don't want to hide that information.