Married Couple Buying 1st House

Not likely. You need to prove that any mortgage can be paid back to the financial institution that holds your mortgage.

While your limited income and bad credit will likely make it very difficult and challenging for you and your spouse to get a mortgage loan, it is possible if your credit score isn't too low (for example, an FHA loan requires a minimum FICO score of 500) and your income will be enough to cover your mortgage payment without exceeding an acceptable debt to income ratio (for FHA loans, the monthly mortgage payment generally cannot exceed 31% of monthly gross income and total debt payments, including the mortgage payment, cannot exceed 42% of gross monthly income). It is good that you have enough for a large downpayment as lenders will often require a higher downpayment if you have bad credit (for example, if your credit score is below 581, a 10% downpayment would be required for an FHA loan).

If you don't meet the minimum underwriting requirements for a conventional, FHA, VA or USDA mortgage loan, you may still be able to get one through programs such as the Fannie Mae Community HomeChoice program which relaxes some underwriting requirements for disabled homebuyers with low to moderate incomes. There are also a number of other federal, state and local government and non-profit programs that provide disabled homebuyers with various types of assistance to purchase a home.

The average ssdi income is $1146/month. I'm not so sure that's enough to fund a mortgage.

They can also apply to Habitat For Humanities.

The maximum monthly SSDI benefit for 2014 is about $2642. The average monthly SSDI benefit for 2013 was indeed $1146.43 but it's certainly possible that the original poster has a monthly benefit significantly higher than that.

Whether the average monthly SSDI benefit payment would be enough depends on the sale price and the amount of the mortgage loan. There are a number of areas in the United States where the cost of housing is low enough that 31% of $1146 would easily suffice to cover a monthly mortgage payment (including principal, interest, property tax and insurance). If the prospective borrower has funds for a large downpayment, the available options would increase significantly. However, finding a lender who will provide a a smaller mortgage loan can be difficult as the fixed transaction costs make these loans less profitable.

Interestingly enough, there seems to be a significant gender disparity in average monthly SSDI benefit amounts with the average monthly benefit for disabled female workers being consistently (over the past 50 years) less than the average for disabled male workers. In 2013, 4,299,678 women received an average monthly SSDI benefit of $1011.42 each while 4,642,906 men received an average benefit of $1271.46.

It's possible, but neither of us really knows, because they didn't share that info.

I'm still going with the 'average' rather than the max. To get the max, they would have had to pay into FICA at the highest rates. Highly unlikely from MPOV.

Check with a mortgage broker -- it depends on how bad your credit is. What happens is they will look at your combined income, so if he has no income you can still have both your names on it. That will not impact it. Basically they will look at your income, your credit scores and percentage you put down to determine what you can afford.

If your income is high enough even (but of course it depends on how bad your credit score it) -- with a lower credit score you can potentially get a mortgage. Your interest rate will potentially be higher as a result -- you are more risky. They will take your income and down payment and determine what you can afford to pay for a mortgage. If your credit score is really low you may be rejected.

It would be best to talk with a few mortgage companies/agents. They should be able to do a free analysis and let you know if you are likely to qualify. You should do this before you go home searching any way so you know what you can realistically afford and so when you provide an offer the home owner is confident you will quality for a mortgage.

Another positive to doing this -- is if you do not qualify, a good mortgage broker will give you pointers on what you can do to get a better credit score. So say maybe this year you do not qualify, there may be things you can do or stop doing that will help your credit score get better.

Here's a calculator that may provide some insight into your own situation.
http://tcalc.timevalue.com/all-financial-calculators/mortgage-calculators/mortgage-qualification-calculator.aspx