Deloitte projects the Federal Reserve will keep policy rates unchanged through December 2026 and that the 10‑year U.S. Treasury yield will settle near 3.9% from the third quarter of 2027 through the end of 2030, offering a clear multi‑year benchmark for mortgage pricing.
The forecast matters because mortgage borrowers use the 10‑year Treasury as a reference for long‑term mortgage costs; with mortgage markets still jittery after recent global shocks, Deloitte’s timeline gives lenders and homeowners a specific horizon for when yields may calm. Michael Wolf of Deloitte frames the firm’s view as a gradual easing: the Fed stays on hold until December 2026, the average federal funds rate drifts to a neutral 3.125% by mid‑2027, and the 10‑year yield falls through the second quarter of 2027 before stabilizing at about 3.9%.
Mortgage markets have been volatile since the start of the Middle East conflict, and that volatility shows up in current pricing: as of March 5 the 10‑year yield was 4.09% and the 30‑year fixed mortgage rate was 6.00%, a gap of 1.91 percentage points. That observable spread is central to how interest rates today translate into monthly payments — mortgage rates typically move with Treasury yields but sit higher because lenders charge for added risks and market frictions.
Put plainly, the 10‑year yield is the anchor and the spread is the amplifier. Historically, from 2010 to 2020 the spread between the 30‑year fixed mortgage and the 10‑year Treasury was under two percentage points and often near 1.5. In recent years that margin widened: quantitative tightening after 2022 pushed private investors to absorb more mortgage‑backed securities, which widened spreads. Claude AI’s assessment in the data captures that mechanism, and it also notes that spreads began normalizing in late 2025 and are expected to continue tightening.
Those mechanics turn forecasts into practical consequences. If the 10‑year yields settle at Deloitte’s 3.9% and spreads drift back toward the 2010–2020 norm of roughly 1.5 points, a typical 30‑year mortgage could be near the mid‑5 percent range. If spreads remain near today’s roughly 1.9 points, mortgage pricing would sit higher, closer to the upper‑5s or low‑6s. The Congressional Budget Office offers a somewhat different pace for yields — projecting about 4.1% by the end of 2026 and roughly 4.3% by 2030 — which would push mortgage math upward unless spreads compress further.
The plan is not uncontested. Over a longer horizon Goldman Sachs expects the 10‑year to rise to 4.5% by 2035, a materially higher endpoint than Deloitte’s 3.9% plateau for 2027–2030. That divergence is the friction point: forecasts for the Treasury drive headline mortgage expectations, but differences among credible forecasts — and, crucially, how the mortgage spread behaves — can change borrower outcomes by several tenths of a percentage point or more.
For homeowners and prospective buyers sorting through interest rates today, the immediate takeaway is twofold: watch the path of the 10‑year Treasury and watch the spread between Treasuries and 30‑year mortgages. The Treasury forecast gives a baseline for where nominal rates might go; the spread determines how much above that baseline mortgage rates will actually sit.
The next clear calendar marker is December 2026, when Deloitte expects the Fed to still have rates unchanged and when market participants can reassess whether yields and spreads are tracking the firm’s scenario. The most consequential unanswered question is not which forecast is numerically correct, but whether spreads will compress back toward pre‑2022 norms — that relationship will decide whether a 3.9% Treasury translates into affordable mortgage rates or keeps borrowing costs elevated.
