themortgagellm™Use Case · GSE Eligibility Check (Fannie + Freddie)
Check a specific loan against Fannie Mae's Eligibility Matrix and Freddie Mac's Seller/Servicer Guide (Chapter 4203) in one step. Paste the loan profile in chat and get a side-by-side verdict from both GSEs — including the specific LTV/FICO/DTI checks each one ran, and Selling Guide / Chapter section citations on any failures. Designed for loan-officer triage before a Desktop Underwriter or Loan Product Advisor submission.
Sample prompts
Clean 1-unit primary purchase at 90% LTV
“Check Fannie + Freddie eligibility: purchase, 1-unit primary, $360K loan on $400K value, 720 FICO, 38% DTI, first-time homebuyer.”
✅✅ Eligible to both Fannie Mae and Freddie Mac at 90% LTV. The standard happy path — a clean conforming purchase fits both matrices, both panels show six passing checks each…
97% LTV FTHB: Fannie eligible, Freddie not
“Check GSE eligibility: purchase, 1-unit primary, $388K loan on $400K value, 720 FICO, 38% DTI, first-time homebuyer.”
✅❌ A real divergence: Fannie's FRM ceiling for FTHB loans goes to 97%, but Freddie's standard matrix caps at 95% — so a 97% LTV first-time-homebuyer loan is deliverable to Fannie but not to Freddie…
1-unit investment LCOR at 80% LTV: Freddie eligible, Fannie not
“Will Freddie buy this? Limited cash-out refi, 1-unit investment, $320K loan on $400K value, 740 FICO, 40% DTI.”
❌✅ The other real divergence: Fannie caps 1-unit investment LCOR at 75% LTV (separate from purchase's 85%), but Freddie lumps purchase + LCOR at 85% — so the same 80% LTV LCOR clears Freddie but not Fannie…