I disagree with all the other posts. Social Security Disability does have a work requirement. It is similar to insurance. If you stop paying your car insurance, your policy lapses and nothing would be paid on an accident. You husband does have to have paid FICA/OASDI/Social Security taxes to earn the credits required and if he is over age 31, he has to have 20 credits in the 40 credit period before he became disabled, roughly 5 years in the last 10.
So he had a business for 5 years and had no profit at all? Did he even file income taxes and claimed a loss for 5 years? I am always curious about why someone would work for 5 years and make no profit, no money. Perhaps a good discussion with your accountant might be in order. Can the tax return be legally amended to show that the business made some profit? He would have to pay the taxes owed on the profit.
What kind of earnings did he have the 5 years before he started working at this self-employment? Was he paying FICA taxes on his wages from an employer?
If he does decide to talk to an attorney, bring along his earnings record and tax records for the last 10 years and hope you find an attorney who also understands filing tax returns and insured status.
He needs to know his Date Last Insured (can get it from SSA). Once he has that, he might be able to try for an earlier onset date, but that might be a long shot too.
And if he was approved for SSI on the initial application, that is proof that people are approved the first time. So it sounds like the only hurdle (and it is a big one) is the earnings history and lack of paying FICA taxes.