Killing a $200/Month PMI Premium 10 Months Early Beats Investing the Same $300, Usually
We ran a common scenario: a $350,000 home with a $315,000 balance (90% loan-to-value) and a $200/month PMI premium. Paying an extra $300/month toward principal reaches the 80% LTV removal threshold roughly 10 months sooner than the standard payment schedule alone. Treating that extra payment as earning a guaranteed return equal to the mortgage rate, plus the PMI premium saved for those 10 months, beats investing the same $300/month at a modest return assumption — though the comparison flips once the assumed investment return climbs high enough above the mortgage rate.
The two paths
| Accelerate PMI removal | Invest instead | |
|---|---|---|
| $300/month goes to | Extra mortgage principal | Investment account |
| “Return” earned | Mortgage rate (interest avoided) | Assumed investment return |
| PMI premium | Stops ~10 months early | Continues the full standard duration |
The framing that makes this comparable to a standard “pay down debt vs invest” decision: extra principal payments earn a guaranteed return equal to whatever interest they avoid — your mortgage rate. That’s directly comparable to an investment return assumption, plus this path gets a bonus most debt-paydown comparisons don’t have: the PMI premium itself stops early, an additional, separate savings on top of the interest-avoidance return.
Why the PMI bonus matters more than people expect
A standard “pay down your mortgage vs invest” comparison is usually a close call when your mortgage rate is in the 5-7% range and reasonable investment return assumptions are similar or higher. PMI changes that calculus by adding a second, distinct savings stream — a fixed monthly cost that simply disappears once you cross the threshold, on top of the interest-avoidance return. That extra bonus is why accelerating PMI removal can beat investing even when a pure “pay down mortgage vs invest” comparison (without PMI in the picture) would be closer or favor investing.
Where this framework doesn’t apply
- Your home has already appreciated. If your area’s values have risen since purchase, your actual current LTV may already be at or below 80% without any extra payments — a current valuation is a cheaper first step than months of overpaying.
- Your investment return assumption is realistically aggressive. If you have a strong, sustained track record or high conviction in a higher expected return, the comparison can flip — run your own numbers rather than assuming acceleration always wins.
- Your emergency fund isn’t solid yet. Extra principal payments are illiquid — that money is much harder to access in a true emergency than a taxable investment account. If your cash buffer is thin, building that first has value this comparison doesn’t price in.
- Your loan has non-standard PMI terms. A few loan types require PMI for a minimum period regardless of LTV — confirm your specific terms with your servicer before planning around the standard 80% threshold.
What to actually do
- Check your home’s current value first — appreciation may have already gotten you close to the 80% threshold.
- If not, decide on a realistic extra-payment amount and an honest (not aspirational) investment-return assumption.
- Make sure your emergency fund is solid before committing extra cash to illiquid home equity.
- Once you hit 80% LTV, contact your servicer proactively — removal is typically borrower-requested at that threshold, not automatic.
- Confirm your specific loan’s PMI terms and any appraisal requirements with your servicer.
For the underlying mortgage payment math this builds on, see how much a 1% rate change actually costs per month.
Open the PMI Removal Calculator → and run your own home value, balance, and investment-return assumption.