A mortgage buydown uses upfront funds either to purchase a lower note rate or to subsidize scheduled payments for a limited opening period.
A mortgage buydown uses money paid at or before closing to reduce borrowing cost or the amount the borrower initially pays. A permanent buydown purchases a lower contractual note rate, usually through discount points. A temporary buydown generally leaves the note rate unchanged and uses a funded account to cover part of the first years’ scheduled payments.
The distinction is essential. A temporary 2-1 or 3-2-1 buydown is not an adjustable-rate mortgage and does not erase the borrower’s obligation under the note.
| Feature | Permanent buydown | Temporary buydown |
|---|---|---|
| What changes | Contractual note rate | Borrower’s scheduled contribution during an opening period |
| Typical funding | Discount points | Lump sum placed in a subsidy or custodial account |
| Duration | Remaining loan term unless loan ends or changes | Defined schedule, commonly one to three years |
| Payment at end | No scheduled step-up caused by the buydown | Borrower pays the full note payment after subsidy ends |
| Core analysis | Point cost and break-even | Funding adequacy and later-payment affordability |
Marketing may use “rate buydown” for either structure. The note, Loan Estimate, Closing Disclosure, and any buydown agreement determine what actually changes.
The borrower or another permitted party pays Discount Points in exchange for a lower offered rate. The point cost is:
One point on a $400,000 loan is $4,000. The amount by which it lowers the rate is not fixed. The borrower should compare actual rate-and-cost combinations for the same loan scenario and lock period.
The simplest evaluation divides incremental upfront cost by monthly payment savings. A fuller comparison also considers other fees, the expected holding period, opportunity cost, and the possibility of sale, prepayment, or refinancing.
A temporary buydown calculates opening payments using rates below the note rate for presentation and subsidy purposes. The note itself ordinarily remains at the full contractual rate. Each month:
For eligible Fannie Mae loans, temporary buydowns require a written agreement, may run for no more than three years, and do not change the note terms. Fannie Mae also requires qualification at the note rate and states that the borrower remains obligated for the full note payment if buydown funds are unavailable. Other programs and lenders may use different rules.
Assume a $400,000, 30-year fixed-rate mortgage with a 6.50% note rate. Scheduled principal and interest is about $2,528.27 per month.
The payment is calculated as if the rate were 4.50% in year one and 5.50% in year two:
| Period | Payment-rate equivalent | Borrower amount | Monthly subsidy |
|---|---|---|---|
| Year 1 | 4.50% | $2,026.74 | $501.53 |
| Year 2 | 5.50% | $2,271.16 | $257.12 |
| Year 3 onward | 6.50% note rate | $2,528.27 | $0 |
The illustrative account needs about $9,103.76 to fund the 24 monthly differences. The borrower’s note obligation and underwriting payment remain based on the 6.50% note rate under the cited agency framework.
Suppose one point, or $4,000, obtains a 6.25% note rate. Principal and interest falls to about $2,462.87 for the term, a difference of about $65.40 per month. The simple break-even is about 62 months.
These examples isolate mechanics. Actual rate sheets, fees, contribution rules, and payment calculations control.
Depending on the loan program and transaction, funding may come from the borrower, seller, builder, lender, employer, or another permitted source. Funding source affects underwriting, disclosure, and contribution-limit treatment.
A seller-funded buydown should be compared with alternatives such as a lower purchase price, closing-cost credit, repair allowance, or larger borrower reserve. The headline subsidy may be partly reflected in the negotiated economics of the sale.
Ask whether the note rate changes. If it does, identify points and rate. If it does not, obtain the temporary buydown agreement, payment schedule, funding amount, custodian, and treatment of unused funds.
For a temporary buydown, prepare the household budget using the full note payment plus taxes, insurance, association charges, and other housing costs. Expected income growth is uncertain and should not substitute for present affordability.
Determine whether the same funds could reduce principal, cover closing costs, preserve emergency reserves, or support a different transaction price. Compare complete Loan Estimates rather than isolated monthly payments.
For permanent points, estimate break-even before a possible sale or refinance. For a temporary subsidy, determine what the agreement says about payoff, transfer, foreclosure, and unused funds.
This material is educational. Mortgage terms, underwriting, disclosures, and contribution limits depend on the lender, program, jurisdiction, and transaction; this is not individualized mortgage, legal, tax, or financial advice.