That would be your permanent fix.

The pig in the python.

More than half the time, one or the other will be around at 90, so you definitely need your money to last until at least 90.

Suppose longevity goes way up, and we're all living to 115, ... We can't expect to retire at 65 and take our final 50 years off. On the other hand, do we want to work until 100 and have a traditional 15-year retirement?

The fix doesn't necessarily have to be on the Social Security side but may be on the tax or budget side.

There is no painless way to solve Social Security's solvency problems.

You want your market value of assets to be close to or above that number. Then you know it's 100 percent funded.