Health Insurance Question....

Hello,

Are there any health insurance experts in the audience?My friend had been told she was going to be layed off from her job at the end of last year (12/2017). To prepare for this, her husband enrolled in the medical & dental insurance offered through his job, beginning in January 2018. As it turned out, my friend did not get layed off and she is still with the same employer. Meanwhile, the husband and son have each gone to the doctor during January 2018 and used the wife's employer-subsidized insurance as in the past. I pointed out that as both she and her husband have coverage, her husband's insurance was now "primary" for him, as well as for their son (his birthday is in the first 6 months of the year). The wife has asked me if she needs to notify her insurance company about the mistake. I am thinking that the proper thing is for the wife to call her health insurance company and explain what happened, with the expectation that the company will ask that any funds paid for the husband's and son's visits be reimbursed - and then my friend should get the bills reissued from the physicians' offices (I doubt they will resubmit for them) and send to husband's insurance company? Or, should they just start using the husband's insurance next time he or their son go to the doctor and/or need to have prescriptions filled? Or, ________ (please fill in the blank with your suggestions).

Please help

I didn't find the right solution from the internet.

References:
www.bogleheads.org/forum/viewtopic.php?t=240236
Motion Infographics Animation Company

Thank you