A 1095-C is a tax form issued by an employer to an employee (and other eligible household members) to show information about the healthcare coverage the employee had. You should expect a Form 1095-C if you had coverage through your employer or through Medicare.
The IRS requires all 1095-C's to be issued by January 31st.
If you have questions about your 1095-C form, please contact your employer or the Centers for Medicare and Medicaid Services (CMS).