Fat fire = 100k x 25 = 2.5 mill
By average I am considering what 2019 medscape rated all physician salaries around 300k average of course that counts specialists with pcps.
Do people hit this 10,15,20 years into their attending life if we define the numbers above?
As fast as you want really. Name the time period and I'll tell you how to do it. I'd aim for 20 years though. At that limit, it looks like this:
(note all numbers are after inflation, so this is 2.5M in today's dollars):
=NPER(5%,-75000,0,2500000) = 20 years
So at a 5% after inflation return, saving $75K/year, it will take you 20 years to hit $2.5M in today's dollars. That's a 25% savings rate.
Now, let's say you want to do it in 10 years. Here's an option:
=RATE(10,-150000,0,2500000) = 11%
So if you earn 11% after inflation and save $150K a year, you'll hit $2.5M in today's dollars in 10 years.
Note that earning 11% real will require a lot of leverage and market risk and likely some sweat equity into something like real estate.
You could also start a side gig business that pays $100K/year, you save 60% of every dollar it pays out, and you sell it for $500K in 10 years. All the while you're earning $300K at your main gig and saving $60K a year there. Now you're putting away $160K/year and you'll get $500K at the end. What kind of return do you need now?
Again, about 11%. But what if you sold that side gig for $1M and it paid you $150K a year? Now you only need a 0% real return. You can probably get that with bonds or CDs.
But that's what you can do. What actually happens is:
25% of docs never become millionaires
Another 25% never hits $2.5Mish
Another 25% hits it after 30+ years
And then there is the 25% who starts asking these questions in med school....