my husband was just laid off. the company said it was due to lack of work. He was the only person in a department of roughly 30 some.

You would have a cause of action if you can prove that the reason for the termination was due to your husband's medical condition.  This would then violate the ADA and possibly ERISA.  The company will have to establish that there was in fact a need to lay off an employee, and then explain why they chose your husband instead of another person, assuming there was a legitimate need for a lay off.  If the company replaced your husband with another person, that will be a big step to prove discrimination since it shows there was no need for a lay off.  While there is no rule, absent a union contract, that requires a certain priority be followed for a lay off, companies typically base the decision on one or more of the following: seniority, performance as compared to other employee performing the same job duties and having the same title, prior discipline, having or lacking a special skill set that the company needs, or some other legitimate and logical reason.  You should meet with an attorney to further explore the facts and make a written request for your husband's personnel file