Good news, I maxed my 401k this year (for the 3rd or 4th year in a row). Now that my take home pay is larger, there's plenty of extra dough to throw into investments, or pay down the house.
Other update -- I was wrong about the biweekly payment (so I stopped doing it). It just takes half the payment and holds it rather than immediately putting the money towards the balance. I should just put it on autopay and leave it, though. When you opt in, it says you'll end up squeezing in an extra payment each year but I didn't stay with it long enough to find it.
It is very likely that I'll continue to max my 401k each year until I pull the plug on full-time work. That could be as soon as 2023, or as late as 2026. After expenses are covered each month I'll probably throw most of the excess cash into investments, and maybe an extra $500 - $1000 at the house on occasion. [edit] If I quit that early, we'll still have the mortgage. I'd just ramp up my side hustle and DW would continue to work full time.
Once the portfolio reaches the point of "enough," I'll be waaay more aggressive in paying down the house, probably flipping to like 75% towards house and 25% into investing, or at least 50/50. If the market dips, I have the flexibility to revert back to aggressively investing. Same thing if the market dips tomorrow -- prioritize buying more shares on sale and throw less money at the loan.
Psychologically speaking: what's real is the $750+ I'm paying in interest each month on the loan. So far this year I've paid about $6,000 in interest. I know, I know -- my investments have grown by more than the amount I've paid in interest... and the first year(s) of the loan are where you pay the most in interest. Each monthly payment is $3 less in interested and $3 more in principal. The question is how much of my real/earned dollars am I willing to spend on interest payments at the opportunity cost of potential/very likely investment gains? $50k? $100k? $400k? I guess the question is, how many times do I [personally] want to buy my house over the course of the loan? My answer is as few as possible. The better answer is that maxing the 401k is a component of that bigger picture, as well.
In terms of the numbers, as it has been months since my initial post:
Current Mortgage Balance: $389k ][ Balance @ Feb when originally posted: $396k
Remaining income to be earned this year: 9 more pay periods @ $3,100 ea = $27,900
Wife's income to be earned this year: 9 more pay periods @ $2,250 ea = $20,250
Remaining monthly expenses: 4 months, $3k each = $12k (this includes regular mortgage payment & spending has finally slowed down)
So $50k (rounding up bc I have a side hustle) - $12k = $38k
We have $38k to play with between now and Jan 1, 2022. In the first 8 months of the year we dropped the mortgage balance by $7k, put $17k into taxable brokerage account, and $19.5k into the 401k. Wife is contributing to her 401k to get the company match, and I'm not privy to her balance yet because she is recently-eligible.
So even if I just threw another $13.5k into the investment bucket, that would be adding a total of $50k ($19.5k+$17k+$13.5k) to our investment balances this year and still leaves another $24.5k($38k-13.5k) to either invest, throw at the mortgage, or use to build up cash reserves, etc. I will disclose this has been a tremendously spendy year for us -- to the tune of about $25k in additional expenses from the new home* and paying for a long overdue wedding reception that we never got to have. Next year I imagine we'll revert to being non-spendy pantses and we will have closer to $75k-$80k of after tax income to either invest or throw at the house.
(Big picture mentioned above) At the end of the day it comes down to currently needing a $900k stash for both of us to make work fully optional if we want to maintain the mortgage. The mathematically fastest way to do this is by prioritizing investing and not wasting additional resources paying down the house [right now]. The fastest path is to get to the $900k via investing.
Rough numbers: ~$440k retirement & non retirement accounts & the $389k owed on the mortgage.
(yes, forgot to mention we put money into a HSA as well)
*screen in deck, wrap deck, seal aggregate driveway, concrete "curbing" in yard, DIY fire pit & wall kit (from Romanstone.com), concrete slab addition to back yard & under deck; reception vendors: food truck, photographer, etc. -- all stuff that's not an annual expense.