If your husband received this 1099-MISC for work he did in 2017, then you need to report this as Self-Employment income on Schedule C. the IRS considers this as meaning he is self-employed, selling his services to the company he worked for. By reporting the income on a Schedule C, the income will cause the program to generate the Self-Employment tax he needs to pay. That's social security and medicare tax he owes since the company did not take out those taxes from his pay.
