The short version
Having student loans won't stop you from buying a house. What matters is the monthly payment the lender plugs into your debt-to-income ratio, and that number isn't always what you actually pay each month.
Every loan program has its own rule. Conventional loans backed by Fannie Mae can count a documented $0 income-driven payment as $0. FHA, and loans sold to Freddie Mac, will usually add a payment of 0.5% of your balance if you're paying nothing. On a $60,000 balance, that's $300 a month that exists only on paper, and it can cost you somewhere around $45,000 of buying power.
So the question isn't really 'can I buy with student loans?' It's which program treats your loans best. I run it both ways before anyone goes house hunting.
How do student loans affect mortgage approval?
Through one number: your debt-to-income ratio, or DTI. The lender adds up your monthly debts, including the new house payment, and divides that by your gross monthly income. Student loans go into that stack the same way a car payment does.
Most approvals top out somewhere in the mid-40s to around 50% DTI, and automated underwriting can sometimes stretch past that with strong credit or reserves. Those caps shift by program and by file, so treat them as approximate. In Sonoma County, where even a modest starter home in Rohnert Park or Windsor pushes the housing payment up fast, there isn't a lot of room to spare. A $400 student loan payment can be the difference between getting approved at $675,000 and getting approved at $620,000.
The balance itself doesn't hurt you much. The payment does. Someone with $150,000 in loans on a $250 income-driven payment can come out ahead of someone with $35,000 on a standard 10-year plan.
What payment will the lender actually count?
This is where it gets program-specific. If your credit report shows a payment above $0, pretty much every program starts there. The differences show up when you're on a $0 income-driven plan, in deferment, or in forbearance, or when your credit report shows no payment at all.
These guidelines have changed several times in the last few years, and I expect they'll change again. Treat the list below as current and approximate, and have your lender confirm the rule on your actual file.
- Conventional (Fannie Mae): uses the payment on your credit report. A documented $0 income-driven payment can generally count as $0. If there's no payment, lenders use 1% of the balance or a documented fully amortizing payment.
- Conventional (Freddie Mac): uses the reported payment if it's above $0. Otherwise it's typically 0.5% of the outstanding balance.
- FHA: uses the reported payment if it's above $0. At $0, deferment, or forbearance, it's 0.5% of the balance.
- VA: loans deferred at least 12 months past closing can often be left out entirely. Otherwise there's a threshold calculation based on 5% of the balance divided by 12, with some room to use a lower documented payment.
- USDA: generally the reported payment, or 0.5% of the balance if the payment is $0 or deferred.
Why does the loan program matter so much?
Let me put real numbers on it. Say a nurse at one of the Santa Rosa hospitals makes $9,500 a month, has $80,000 in federal loans, and is on an income-driven plan showing a $0 payment.
Run through a Fannie Mae conventional loan with the right documentation, her student loan payment counts as $0. Run the same file through FHA and the lender has to add $400 a month. With rates in the mid-6s, a $400 monthly hit supports roughly $60,000 of loan amount. Same person, same loans, same income. One program lets her shop about $60,000 higher than the other. Rates move, so rerun that math for your own numbers.
It works in the other direction too. If your credit score is in the low 600s, conventional pricing can get ugly, and FHA may still win even after the 0.5% hit. There's no universal best program, only the best one for your file. A lot of loan officers never run the comparison. Ask for it. It takes ten minutes.
What if my loans are in default or collections?
That's a bigger problem, and it's more common now than it was a couple of years ago. Federal student loan collections came back in 2025 after a long pause, and a lot of borrowers found out the hard way that their loans had quietly slipped into default.
Defaulted federal debt shows up in a government database called CAIVRS. If you're flagged there, you can't get an FHA, VA, or USDA loan until it's resolved, usually through rehabilitation or consolidation. Conventional loans don't check CAIVRS the same way, but a default or a string of late payments will drag your credit score down, and that costs you on rate.
If you haven't logged into your servicer's site in a while, do it this week. I'd rather you find a problem six months before you apply than two weeks into escrow. I've watched that happen, and there's usually no quick fix once you're already in contract.
How can I improve my odds before I apply?
Most of this is paperwork, not money. Federal repayment plans have been reshuffled more than once lately, so check what your servicer actually shows today before you plan around it.
- Get your income-driven payment reported. If your credit report shows no payment, lenders fall back to a percentage of the balance, which is almost always higher than your real payment.
- Download your servicer statement showing the current monthly payment and your plan. Underwriters ask for it constantly.
- Don't use your down payment to pay off student loans before talking to a lender. Wiping out a $20,000 loan might help your ratio less than keeping $20,000 for down payment and reserves.
- Leave forbearance before you apply if you can. On most programs, forbearance means the lender counts a percentage payment anyway, so it doesn't buy you anything.
- Check with your servicer before you consolidate or switch plans in the middle of a mortgage application. A new payment amount can send the underwriter back to square one.
- Look at CalHFA and local down payment assistance. Those programs don't erase your student loans, but more money down means a smaller payment and more room in your DTI.