Where 640 and 680 Part Ways on an IHDA Loan
Program and regulatory figures verified September 25, 2026. Details change; confirm your scenario with us.
The published floor is 640, and that number is repeated everywhere. The number that actually reshapes a government file is 680.
The matrix
| Loan type | FICO score | Maximum back-end DTI |
|---|---|---|
| FNMA / FHLMC conventional | 640 and above | 50.00% |
| FHA, VA, USDA | 680 and above | 50.00% |
| FHA, VA, USDA | 640 to 679 | 45.00% |
Read the bottom row again, because it inverts an assumption. Most buyers treat FHA as the forgiving option and conventional as the strict one. On an IHDA file with a 650 score, conventional allows a 50.00% back-end ratio and FHA allows 45.00%.
Five percentage points of DTI is a meaningful amount of house. On a file where the ratios are the binding constraint rather than the down payment, the loan type choice deserves a fresh look rather than a reflex.
The 45.01% to 50.00% band has its own rules
IHDA treats the top of the DTI range as a distinct risk tier with two conditions attached.
- The homebuyer education must be Finally Home! specifically, completed prior to close.
- On FHA, USDA and VA the credit score must be 680 or higher. Below 680 requires a prior-to-close exception.
The education point catches files late. A buyer who completed a different approved course, then saw their ratios drift above 45.01% during underwriting, has to take a second course before closing. Education rules in full.
One honest note on IHDA's own table
IHDA's summary table in the guide lists "Greater than or equal to 45.00%" against all approved providers, and "45.01% - 50.00%" against Finally Home!, which overlap. The prose above that table is unambiguous and is what we have published: loans with DTI 45.01% to 50.00% must use Finally Home!.
We are not going to invent a clean threshold for the range below that beyond what IHDA states, which is that an approved provider is required. If your ratios are close to the line, treat Finally Home! as the safe choice and ask us.
Mortgage insurance
Lender-paid mortgage insurance is not available on any IHDA Mortgage loan. Borrower-paid monthly, split premium and single premium are all allowed, and reduced coverage may apply on FNMA HFA Preferred and FHLMC HFA Advantage following the automated findings.
Other credit-side rules worth knowing
IHDA offers fixed-rate products only, not exceeding a 30-year term, fully amortizing. Negative amortization, buydown products, balloons and adjustable-rate mortgages are not allowed. Prepayment penalties are prohibited, as is single-premium credit insurance. Investment properties and second homes are not eligible.
A full appraisal is required on every loan and Property Inspection Waivers are not allowed, which is worth planning for on a fast closing. Property rules.
See also the complete eligibility test and pairing assistance with an FHA loan.
Frequently asked questions
What credit score is needed for IHDA down payment assistance?
640 is the floor in IHDA's published matrix. On conventional loans through Fannie Mae or Freddie Mac, 640 and above allows the maximum back-end DTI of 50.00%. On FHA, VA and USDA loans, 640 to 679 caps the maximum DTI at 45.00% and 680 or above allows 50.00%. Loans in the 45.01% to 50.00% DTI band on government loan types require 680 or higher, with anything lower needing a prior-to-close exception.
What is the maximum DTI for an IHDA loan in Illinois?
50.00% back-end with automated underwriting approval, effective 8.15.2023 per the IHDA guide. That maximum is available on conventional loans from a 640 score, and on FHA, VA and USDA loans from a 680 score. On FHA, VA and USDA loans with a score between 640 and 679 the maximum is 45.00%.
Why does FHA have a lower DTI cap than conventional on IHDA loans?
IHDA's matrix applies the 680 score threshold to FHA, VA and USDA loans but not to conventional Fannie Mae and Freddie Mac loans. The practical effect is that a borrower with a 650 score can reach a 50.00% back-end ratio on a conventional IHDA loan but is capped at 45.00% on FHA. On files where debt ratios rather than down payment are the constraint, that makes conventional worth evaluating.
Do I have to take Finally Home! education for an IHDA loan?
Only if your back-end DTI lands between 45.01% and 50.00%. The IHDA guide states that loans in that band must use Finally Home! homebuyer education prior to close. Below that band, an approved provider meeting HUD or National Industry Standards is required. Because ratios can move during underwriting, buyers near the line often choose Finally Home! from the start.
Is lender-paid mortgage insurance available on IHDA loans?
No. The IHDA guide states that LPMI is not available on any IHDA Mortgage loan. Borrower-paid monthly, split premium and single premium mortgage insurance are all allowed. On FNMA HFA Preferred and FHLMC HFA Advantage loans, reduced mortgage insurance coverage may apply according to the automated underwriting findings.
Mike Certo · NMLS #260555 · Cornerstone First Mortgage NMLS #173855 · Equal Housing Lender. Educational content about financing, not a loan commitment and not legal or tax advice. IHDA program terms, income limits and purchase price limits are set by the Illinois Housing Development Authority and change; figures here carry the date we verified them and IHDA's own disclaimer applies, that funding and availability are subject to change and are not guaranteed until a complete reservation is placed. Loans are subject to borrower and property qualification.