Retirement tax questions

Although through payroll deduction, it appears that I paid the premiums as if out of pocket (unlike my medical insurance premiums).    I will actually be paid the benefits from the third party (starting next week) through my employer's payroll system, and they are suggesting that it will be treated as if it was wages, vacation pay, etc, W/H, the whole nine yards.  Why should this be added to my YTD stub totals and/or W2?  Doesn't sound right.