Actually, it is NOT the employer portion only. It is the premium amount paid to the insurer for coverage for the year (if fully insured) or, there are some options for what to report for self-insured companies.
Source: <a rel="nofollow" target="_blank" href="
https://www.irs.gov/Affordable-Care-Act/Form-W-2-Reporting-of-Employer-Sponsored-Health-Coverage">ht...>
"In general, the amount reported should include both the portion paid by the employer and the portion paid by the employee. See the chart, below, and the questions and answers for more information."
