The DUS lender executes the loan into a DUS MBS that is sold to investors at a market-determined spread to the matching-tenor Treasury. That MBS spread plus Fannie's guarantee fee plus the DUS lender's servicing spread plus any program-specific add-ons equals the gross note rate the sponsor sees. Rising MBS spreads (typical in volatile markets) widen sponsor pricing one-for-one.
DUS rate stack: line by line
Line 1: matching-tenor Treasury (5-year for a 5-year DUS, 7-year for a 7-year DUS, 10-year for a 10-year DUS). This is the underlying risk-free rate.
Line 2: the DUS MBS spread to the matching Treasury.
Line 3: Fannie Mae guarantee fee (g-fee). Fannie charges a fee for guaranteeing the timely payment of principal and interest to the MBS investor. The g-fee varies by program tier and execution type but is typically in a defined band negotiated between Fannie and the DUS lender at the corporate level.
Line 4: the DUS lender servicing spread.
Line 5: any program-specific add-ons or buy-downs. Green Rewards, MAH, and Near-Stabilization executions have specific pricing adjustments; cash-out refinances above defined LTV thresholds carry add-ons.
All five lines together produce the gross note rate. The sponsor sees the all-in rate; the DUS lender's quote sheet typically shows the Treasury and the spread to Treasury, with the spread implicitly bundling g-fee, MBS spread, and servicer spread.
Sources
- Delegated Underwriting and Servicing (DUS) program disclosures · Fannie Mae · current
- Multifamily Market Commentary · Fannie Mae Economic & Strategic Research · 2026-Q1
- Treasury Constant Maturity Series (DGS5, DGS10) · Federal Reserve Bank of St. Louis (FRED) · weekly