Good afternoon Pamela,
I'm Doug, and I'm very sorry to hear of your situation. My goal is to provide you with excellent service today.
You are correct, that there is no federal law stating that employers may not provide health insurance for people working less than 30 hours a week.
However, many employer contract with health insurance companies mandate that the employee must be working at least 30 hours to be eligible for health coverage under the policy---and I suspect that is what they are referring to, and not any particular law. Most health policies offered employers have this requirement (30 hours is standard as well) so I am not surprised at the situation that you face---though I certainly empathize with your concerns.
So yes, the company could continue his coverage so long as it does not violate the contract they have with the health care insurance company.
The worst case scenario is that if he loses his coverage through the employer he will be eligible for COBRA so he won't lose benefits. And yes, with COBRA the cost will be higher. But the alternative is that he will have to tough out working 30 hours a week---which may be contrary to his health.
You may reply back to me using the Reply link and I will be happy to continue to assist you until I am able to address your concerns, to your satisfaction.
I hope that I have been able to fully answer your question. As I am not an employee of JustAnswer, please be so kind as to rate my service to you. That is the only way I am compensated for assisting you. Thank you in advance.
I wish you and yours the best in 2016,