Mortgage borrowers watching current mortgage rates should be focused on two numbers: where the 10‑year U.S. Treasury yield goes and how far mortgage rates sit above it. Using recent Treasury forecasts and the long‑run relationship between the 10‑year note and 30‑year fixed mortgages produces a plausible range for borrowing costs over the next five years.
Right now the market sits at a specific point: on March 5 the 10‑year Treasury yield was 4.09% and the 30‑year fixed mortgage rate was 6.00%, a spread of 1.91 percentage points — under two points. That spread level is smaller than the near‑2.5 percentage points that showed up at times after 2022 and larger than the roughly 1.5 point gap typical from 2010 to 2020.
Why the 10‑year matters: mortgage rates and the 10‑year Treasury usually move in the same direction, and lenders price in extra costs above the Treasury yield to cover prepayment risk, credit risk and the market for mortgage‑backed securities. Those factors — the spread — are the main reason mortgage rates are normally higher than Treasury yields.
Two forward paths for the 10‑year sit in the evidence. One set of projections expects yields to ease from here: Deloitte’s outlook assumes the Federal Reserve holds policy steady through December 2026, that the average federal funds rate reaches a neutral 3.125% by mid‑2027, and that the 10‑year will ease through the second quarter of 2027 and then settle around 3.9% from the third quarter of 2027 through the end of 2030. By contrast, the Congressional Budget Office projects the 10‑year will be about 4.1% by the end of 2026 and then rise gradually to roughly 4.3% by 2030; Goldman Sachs sees an even higher long‑run level, with the 10‑year at 4.5% by 2035.
Those Treasury paths map into mortgage scenarios once you add a spread. If the 10‑year drifts toward Deloitte’s 3.9% and spreads remain under two points — as they were on March 5 at 1.91 or near the 2010–2020 norm of about 1.5 — a 30‑year fixed mortgage would sit in the mid‑5% range (for example, 3.9% plus a 1.5 point spread implies roughly a 5.4% mortgage rate). If Treasury yields follow the CBO or Goldman path and spreads widen back toward the levels seen after 2022 — around 2.5 points — mortgage rates would be noticeably higher (3.9% plus 2.5 points would imply about a 6.4% mortgage).
What has driven those spreads since 2022 is clear in market terms: the Federal Reserve’s quantitative tightening program pushed private markets to absorb more mortgage‑backed securities, widening spreads. Market models now show spreads beginning to normalize in late 2025 and continuing to tighten, which helps explain recent downward pressure on mortgage rates even while Treasury yields remain volatile amid the Middle East conflict.
For a prospective buyer or someone weighing a refinance, the practical takeaway is that a sub‑two‑point spread materially reduces borrowing costs even if Treasury yields stay near current levels. A move from a 1.9 point spread to 1.5 points cuts a borrower’s rate by roughly 0.4 percentage point in the simple arithmetic above — enough to change monthly payments and the refinancing calculus.
The uncertainty that matters most is not only the path of the 10‑year but the future level of that spread. Experts differ on the 10‑year’s multi‑year destination, and the market’s ability to absorb mortgage‑backed securities without a return to wider spreads is the open question. If spreads continue to tighten as they did in late 2025, mortgage rates could fall into a noticeably lower band even with modest Treasury yields; if spreads widen again, borrowers could see mortgage costs climb even if Treasury yields are little changed.
Bottom line: current mortgage rates will largely be a function of two linked variables — the 10‑year Treasury and the mortgage‑Treasury spread — and reasonable scenarios place 30‑year fixed rates anywhere from the mid‑5s to the low‑to‑mid‑6s over the next several years. The single most consequential unanswered question is whether spreads return to the sub‑two‑point norms of the 2010s or remain elevated after the post‑2022 adjustment; that answer, more than any single Treasury forecast, will determine how far mortgage rates fall or rise.
