i have a tax lien, anf planning on retiring, can they go after my retirement (pension plan)

They can take a portion of it. You may need an attorney to mitigate you damage here if they go after it.

Disclaimer - This response does not constitute legal, accounting or other professional advice. Only through a personal, confidential consultation with qualified legal counsel can anyone properly evaluate their own unique estate planning challenges and determine what, if any, appropriate legal strategies and tactics should be implemented to meet those challenges.

Circular 230 Disclaimer - “Nothing in this response is intended or written to be used, and cannot be used by any person for the purpose of avoiding tax penalties regarding any transactions or matters addressed herein. You should always seek advice from independent tax advisers regarding the same.”

A federal tax lien is not self--enforcing. However, if the IRS issues a levy to enforce its lien to your pension plan, they can get to your retirement funds, provided you can access them as well. The IRS steps into the shoes of the taxpayer and if you are entitled to receive the money, the IRS can get it.