All money contributed by payroll deduction is considered an "employer" contribution, because the tax laws treat it that you agreed to a voluntary salary reduction that your employer contributed for you. All employer contributions (your own voluntary salary reduction plus any free money) is listed in box 12 of your W-2 using code W. The contributions are also already subtracted from your box 1 taxable wages. You can't take an additional tax deduction because you already aren't paying income tax on the money.
The contribution limit for 2023 was $3850 for single coverage or $7750 for family coverage, plus $1000 catch-up if you are age 55 or older. You could contribute $4850 if you had single coverage and were over 55, or you had family coverage. If you had single coverage and were under age 55, you had an excess contribution and should have paid a penalty and some income tax.
