That depends on your income and the plan. If you are enrolled in the plan whether you actually contribute to it is immaterial if the company does and the W-2 box 13 "retirement plan" box is checked. If it is then then the deductible amount can be reduced or eliminated depending on your MAGI.
See this IRS link for Traditional IRA deduction limits when covered by a retirement plan at work.
https://www.irs.gov/Retirement-Plans/IRA-Deduction-Limits
[Perhaps you need to look further into the plan. If the company "matches" your contributions (up to a limit) then you are throwing "free money" away by not contributing to it.]
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
