The modestly compensated "average Joe" can also get near that number by contributing the max $19,500, getting the 100% employer match of $19,500, the 5% employer match of say $4000... (we're up to $43,000 so far)... 

**...and then, make it a Roth 401(k)** instead of a traditional.   

A dollar in a Roth 401(k) is worth more than a dollar in a traditional, because you're bot having to bring the tax money into the retirement account. The taxes are paid externally to the account, and the money in it is all yours.  If you're in a combined (state + Federal) tax bracket of 28%, $1.00 in a Roth is worth $1.39 in a Traditional.  

(After you pay 28% taxes on $1.39, you are left with $1.00). 

So that $43,000 Roth contrib is as good as a $59,722 Traditional contrib. 

----

"But wait, Harper!  The employer contrib doesn't go into a Roth 401K, it goes into a traditional! That is to say, the employer doesn't pay the tax for you!"

Right, you have to pay that tax, **by doing a Roth conversion inside the 401K**. If they contrib'd $23,500, you convert that to Roth.  

The $23,500 is transmuted into Roth funds **inside the 401K**.  However, the taxes on this event are paid **outside the 401K**.  ***Get it?***  You pay $6,580 in tax, but your 401K becomes worth $6,580 more because it is now post-tax money.  It's a left-handed way of contributing $6,580 additional into the 401(K).  Just instead of writing the check to Fidelity *today* and a check to the IRS *at retirement*, you write a check to the IRS *today* and the value pops into your account.  It's not a free lunch, but it provides the high dollar value of contrib that you are seeking.