Looking into the situation further, we can report that the letters are legitimate and all employers are required by law to comply with the request.
The letter—from Centers for Medicare & Medicaid Services (CMS), a division of the federal Health and Human Services (HHS) Department—is entitled Requirement to Submit the Group Health Plan Report for the IRS/SSA/CMS Data Match. It seeks information on employees, so that CMS may determine whether Medicare is the primary or secondary payer for insurance purposes.
Failure to provide the information can subject the school to penalties of up to $1000 for each worker for whom an inquiry regarding coverage was made. If your school hasn't yet received this letter, there is nothing you need to do. If your school has received this letter, you are urged to comply.
