[ChuckMcM]

Defining 'millionaire' is always dicey depending on who you talk to. In order of strictness:

   $1M or more in adjusted gross income on tax return
   $1M or more in gross income (before adjustments)
   $1M or more in 'liquid' net worth (cash or cash equivalents)
   $1M or more in total net worth.

I know a number of folks who would call themselves a 'millionaire before taxes' which is to say their stock options would give them more than a million dollars when exercised, but since in California you end up withholding 51% for taxes you probably end up with less than a million. There are also folks who bought a house earlier and it has appreciated to be 'worth' more than a million but if they sold it and bought another one they wouldn't want to pay the property taxes on a million dollar house.

And of course a million doesn't go as far as it used to. If you have a couple of kids in elementary school and are planning to pay for their college education, well that's going to be nearly 1/2 million right there depending on school.

Note that there is no dichotomy between more people are millionaires than ones that earn over $400k per year. You can earn $100K per year and invest $20K per year and end up with $1M in savings in 20 years. But it is a long road.