Conventional Loans: Requirements and Guidelines
Conventional loans occupy the largest segment of the U.S. residential mortgage market, operating outside the insurance or guarantee programs administered by federal agencies such as the Federal Housing Administration (FHA) or the Department of Veterans Affairs (VA). Understanding the qualification standards, product variants, and regulatory boundaries that govern conventional lending is essential for borrowers, originators, and real estate professionals navigating the mortgage providers landscape. This page describes the structural characteristics, eligibility criteria, and decision logic applied to conventional loan transactions under current federal conforming standards.
Definition and scope
A conventional loan is a residential mortgage that is not insured or guaranteed by a U.S. government agency. The category divides into two principal types:
- Conforming conventional loans — loans that meet the purchase criteria established by Fannie Mae (Federal National Mortgage Association) and Freddie Mac (Federal Home Loan Mortgage Corporation), as governed by the Federal Housing Finance Agency (FHFA). The conforming loan limit for a single-unit property in most U.S. counties is set annually by the FHFA; for 2024, the baseline limit is $766,550 (FHFA Conforming Loan Limits).
- Non-conforming conventional loans (jumbo loans) — loans that exceed the FHFA conforming limit or otherwise fail to meet Fannie Mae/Freddie Mac eligibility criteria. These are held in portfolio by lenders or sold to private investors rather than government-sponsored enterprises (GSEs).
The regulatory framework for conventional lending draws on the Truth in Lending Act (TILA, 15 U.S.C. § 1601 et seq.), the Real Estate Settlement Procedures Act (RESPA, 12 U.S.C. § 2601), and Regulation Z (12 C.F.R. Part 1026) as implemented by the Consumer Financial Protection Bureau (CFPB). Fannie Mae's Selling Guide and Freddie Mac's Single-Family Seller/Servicer Guide establish the specific underwriting standards that lenders must follow for conforming loans eligible for GSE purchase.
How it works
Conventional loan origination follows a structured underwriting process anchored to standardized eligibility metrics. The primary qualification dimensions are:
- Credit score — Fannie Mae's Desktop Underwriter (DU) system generally requires a minimum FICO score of 620 for most conforming loan products, per the Fannie Mae Selling Guide (B3-5.1). Higher scores qualify for better service levels under the FHFA's Loan-Level Price Adjustment (LLPA) framework.
- Debt-to-income ratio (DTI) — The maximum back-end DTI for DU-approved conforming loans is generally 45 percent, with automated approvals possible up to 50 percent under compensating factors (Fannie Mae Selling Guide, B3-6-02).
- Loan-to-value ratio (LTV) — Purchase transactions with LTV above 80 percent require private mortgage insurance (PMI), a requirement codified under the Homeowners Protection Act of 1998 (12 U.S.C. § 4901). PMI is automatically cancellable when the LTV reaches 80 percent based on original value.
- Down payment — Conforming conventional loans allow down payments as low as 3 percent under Fannie Mae's HomeReady and Freddie Mac's Home Possible programs, targeted at income-qualified borrowers.
- Asset documentation — Two months of bank statements or asset account statements are the baseline documentation standard under Fannie Mae guidelines.
- Property eligibility — The property must meet Fannie Mae or Freddie Mac appraisal and condition standards; non-warrantable condominiums and certain manufactured homes require additional review.
The loan application flows through origination, underwriting (manual or automated via DU or Freddie Mac's Loan Product Advisor), appraisal, and closing. For conforming loans, the lender typically sells the closed loan to a GSE or into the secondary market, recovering capital for future origination.
Common scenarios
Conventional loans serve a broad cross-section of purchase and refinance transactions. The service seeker profile on a reference platform like the National Mortgage Authority provider network reflects several recurring transaction types:
- Primary residence purchase with 20 percent down — The most straightforward conforming scenario; no PMI, full LTV pricing advantage, and standard DU approval path.
- First-time buyer with 3–5 percent down — Eligible under HomeReady (Fannie Mae) or Home Possible (Freddie Mac) if income is at or below 80 percent of area median income (AMI). PMI applies until LTV reaches 80 percent.
- Rate-and-term refinance — A homeowner replacing an existing mortgage without extracting equity. The maximum LTV for a conforming rate-and-term refi on a primary residence is 97 percent under Fannie Mae guidelines.
- Cash-out refinance — Equity extraction subject to stricter LTV caps; Fannie Mae limits cash-out refinances on primary residences to 80 percent LTV for most borrowers.
- Jumbo purchase — Loan amounts above the FHFA conforming limit require non-conforming underwriting. Lenders typically require a minimum FICO of 700–720, DTI below 43 percent, and cash reserves of 12 months or more, though standards vary by institution.
- Investment property financing — Conforming loans permit financing of 1–4 unit investment properties, but LTV limits are lower (typically 75–85 percent) and LLPAs are significantly higher than for owner-occupied transactions.
Decision boundaries
The conforming/non-conforming boundary is the primary structural divide, but additional decision thresholds govern product eligibility. Borrowers with FICO scores below 620 are outside the standard conforming underwriting envelope and must pursue FHA, VA, USDA, or portfolio lending alternatives. The mortgage resource framework describes how lender provider network tools support navigation across these product categories.
Key thresholds that determine product type:
| Factor | Conforming Standard | Jumbo / Non-Conforming Typical |
|---|---|---|
| Loan amount | ≤ $766,550 (2024, standard county) | > $766,550 |
| Minimum FICO | 620 | 700–720 |
| Max DTI | 45–50% (with AUS approval) | 43% |
| Min down payment | 3% (qualified programs) | 10–20% |
| PMI required above 80% LTV | Yes (HPA-governed) | Lender-specific |
Conventional loans also differ structurally from government-backed products in cost architecture. FHA loans carry both an upfront mortgage insurance premium (UFMIP) of 1.75 percent and an annual MIP that persists for the loan's life if the LTV at origination exceeds 90 percent (HUD Mortgagee Letter 2023-05). Conventional PMI cancels automatically at 80 percent LTV, creating a long-term cost advantage for borrowers who can sustain appreciation or paydown to that threshold.
State-level regulations — administered through individual state banking and mortgage licensing authorities, coordinated under the Nationwide Multistate Licensing System (NMLS) — layer additional disclosure and originator qualification requirements on top of federal standards without altering the conforming loan eligibility criteria set by the FHFA and GSEs.