Hi folks - Looking for some advice. We just bought a house and now have a 30 yr, $279k mortgage at 3.5%. We plan to be here long term. This is our only debt and we have an emergency fund. We make around $100k a year, with two kids in childcare ($1000 mo for the next three years, then this will decrease). We currently contribute $950/mo into my husbands 457 (no employer contribution) and my employer puts $450/mo into my 401k. My husband also has a state pension, which they contribute 22% of his salary; and he contributes 6%. We have no plans to retire early, but would like to have the flexibility in ~20 years (I'll be 55; him 59) when our kiddos are out of the house. We feel comfortable with the current state of our retirement savings. We'd like to have our house paid off in ~15 years so we have extra $ monthly to pay for college, if we decide we'd like to. Right now we have the flexibility to contribute an extra $475/mo into our mortgage - this will likely go up with salary increases through time. While we are stashing it monthly, our current plan is to do it as a lump payment of $5700 at the end of each year, should nothing change in our daily life (aka we have a job loss, crazy medical bills, etc). But, due to the low interest rate, I'm wondering if we'd be better off investing it and then using that $ to pay it off all at once once we hit that payoff amount (or keep it invested if we decide we'd rather not pay it off). We currently pay $43/mo in PMI; part of me wants to knock that out as soon as possible but it's so low that not sure it's really a priority. We love the idea of a paid off house, but I can't help to wonder if we're missing out on gains that would be better for us. If we decide to invest, what is our best option? Is it maxing his 457 (but then penalties to remove in ~15 years) or putting in our Roth IRA (we aren't currently contributing but did during grad school..also penalties?)? Or... I don't understand the tax implications of just opening a brokerage account and investing it all in a total market index fund and then pulling it when we want to. Would love some advice. Thanks!