Mortgage Principal Curtailment 2026: How Extra Payments Save You $100,000+
Principal curtailment is the simplest wealth move most homeowners never optimize. $200 extra per month on a typical loan saves $112,000 in interest and 6 years of payments. Here's how it works, the recast trick servicers don't advertise, and the #1 mistake that wastes your extra payments.
⚡ Quick Answer
Principal curtailment = paying extra directly against your loan balance. Your monthly payment stays the same, but your term shrinks and interest savings compound.
- 💵 $200/mo extra on $350K @ 6.5% → save $112,000, payoff 6.2 years early
- 💰 $500/mo extra → save $205,000, payoff 11.4 years early
- ⚠️ #1 mistake: not marking payments "principal only" — servicers default to prepaying next month instead
- 🔄 Want a lower payment instead? That's a recast, not curtailment ($150–$500 fee)
What Is Principal Curtailment, Exactly?
Every mortgage payment splits between interest (the bank's cut) and principal (your equity). Early in a 30-year loan at 6.5%, roughly 75% of your payment is pure interest. Curtailment attacks this directly: every extra dollar goes 100% to principal, which permanently removes the interest that dollar would have generated — for decades.
Two forms:
Partial Curtailment
Any extra principal payment — $100/month recurring, annual bonus lump sums, or one-time windfalls. The most common and flexible approach.
Full Curtailment
Paying the entire remaining balance — at sale, refinance, or final payoff. Request a payoff quote from your servicer (valid 10–30 days, includes per-diem interest).
Exact Savings: $350,000 Loan at 6.5%, 30-Year Fixed
| Extra Payment | Interest Saved | Years Cut | Payoff Year |
|---|---|---|---|
| $100/month | $66,000 | 3.6 years | 2052 |
| $200/month | $112,000 | 6.2 years | 2050 |
| $500/month | $205,000 | 11.4 years | 2045 |
| One extra payment/year (bi-weekly) | $83,000 | 4.6 years | 2051 |
| $20,000 lump sum (year 2) | $71,000 | 3.3 years | 2052 |
Assumes payments start in year 1 of the loan. Starting later reduces savings — the amortization curve front-loads interest.
Run your own numbers with our free extra payment calculator — no login required.
Curtailment vs. Recast vs. Refinance: Which One Do You Need?
| Factor | Curtailment | Recast | Refinance |
|---|---|---|---|
| Monthly payment | Same | Lower | Lower (if rate drops) |
| Loan term | Shorter | Same | Resets |
| Cost | $0 | $150–$500 | 2–5% of loan |
| Credit check | No | No | Yes |
| Keeps your low rate | Yes | Yes | No |
| Best when | You want max interest savings | You want lower payments, have a low rate | Rates dropped 0.75%+ below yours |
The pro combo: curtail aggressively, then request one recast to capture a lower required payment while keeping the shortened payoff trajectory. See our mortgage recasting guide.
If your rate is above 7%, refinancing may beat curtailment entirely. Check today's refinance rates → — if you can drop 0.75%+, run that math first.
Is Curtailment or Refinancing Cheaper for You?
Takes 2 minutes to compare: your current loan vs. extra payments vs. today's refinance rates.
Run My Numbers Free →5 Curtailment Mistakes That Waste Your Money
- 1.Not marking "principal only." By default, many servicers hold extra funds as your next payment — saving you nothing. Always select "apply to principal" and verify on your next statement.
- 2.Curtailing before killing high-interest debt. A 24% credit card always beats a 6.5% mortgage. Clear cards first.
- 3.Draining your emergency fund. Principal payments are one-way — you can't un-pay them without a HELOC or refinance. Keep 3–6 months liquid first.
- 4.Paying for a bi-weekly "program." Servicers charge $300–$400 to set up bi-weekly payments. DIY it free: add 1/12 of your payment to each month as principal-only.
- 5.Ignoring the invest-vs-curtail math. At a 3% pandemic rate, index funds likely win. At 6.5%+, curtailment is a guaranteed return no fund can promise. See pay off mortgage vs invest.
Frequently Asked Questions
What is mortgage principal curtailment?▼
Principal curtailment means making payments directly against your loan balance beyond your required monthly payment. A partial curtailment is any extra principal payment ($100/month extra or a $10,000 lump sum); a full curtailment pays the loan off entirely. Curtailment shortens your loan term and cuts total interest — your required monthly payment stays the same.
What is the difference between curtailment and recasting?▼
Curtailment shortens your loan term but keeps your monthly payment the same. Recasting (re-amortization) keeps your term but lowers your monthly payment after a lump-sum payment — usually $5,000+ minimum and a $150–$500 fee. Curtailment saves more total interest; recasting improves monthly cash flow. Many homeowners curtail first, then recast once.
How much does an extra $200/month save on a mortgage?▼
On a $350,000 loan at 6.5% for 30 years: an extra $200/month saves about $112,000 in interest and pays the loan off 6.2 years early. An extra $500/month saves about $205,000 and cuts 11.4 years. The earlier you start, the bigger the savings because early payments attack the highest-interest portion of the amortization curve.
Is principal curtailment better than investing?▼
It depends on your rate. With a mortgage at 6.5–7%, curtailment is a guaranteed 6.5–7% return — competitive with the stock market's historical 7–10% but with zero risk. With a 3% pandemic-era mortgage, investing usually wins. Rule of thumb in 2026: curtail if your rate is above 5.5%, invest if below 4.5%, split if in between.
Do extra principal payments lower your monthly payment?▼
No — this is the most common misconception. Extra principal payments shorten your loan term but your required payment stays identical. To lower the monthly payment after a big principal payment, you need to request a recast from your servicer (small fee, no credit check) or refinance.
How do I make sure extra payments go to principal?▼
Specify "apply to principal" explicitly — by default, many servicers apply extra money to next month's payment (prepaying interest) instead. Use the principal-only option in your servicer's online portal, or write "principal only" on checks. Then verify your balance dropped by the full amount on your next statement.
Paying 7%+? Refinancing May Beat Curtailment
If today's rates are 0.75% below yours, a refi could save more than a decade of extra payments.
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