DU vs. LP in 2026: Choosing the Right AUS Engine for Your Borrower

DU and LP are not interchangeable. They use different underwriting models with different risk tolerances. An experienced originator runs both when a file is borderline and uses the one that produces the favorable finding, as long as the loan delivers to the corresponding investor and program.

When DU May Perform Better

• ✦Student loan IBR payments: DU uses the actual IBR payment or 1% of the balance if no payment statement exists
• ✦Bankruptcy history: DU can be more lenient on specific post-bankruptcy timelines
• ✦Non-traditional credit: DU has a structured path for alternative tradelines when the borrower lacks three independent accounts
• ✦Cash-out refinances: DU sometimes approves where LP returns a caution on specific cash-out scenarios

When LP May Perform Better

• ✦Multiple financed properties: LP has a streamlined approach for investors with up to 10 financed properties
• ✦Recent job changes: LP can treat recent employment transitions more favorably in some scenarios
• ✦Rental income treatment: LP handles rental income in DTI differently and may yield a more favorable result in specific situations
• ✦Lower FICO with strong compensating factors: LP accepts files that DU refers in some edge cases

Running Both

There is no rule against running both DU and LP on the same file. If DU returns a refer and LP returns an accept, use the accept. The loan must then deliver to the program corresponding to the accepting engine: Fannie Mae for a DU approval and Freddie Mac for an LP accept. Disclose the investor correctly on the Loan Estimate. Both findings must be retained in the file; do not delete prior findings when resubmitting.

Keeping Up With Model Updates

Fannie and Freddie update DU and LP periodically. A borrower who got a refer six months ago may get an approve under a new model version. Subscribe to DU release notes from Fannie Mae and LP release notes from Freddie Mac to stay current on model changes that affect your file population.