I retired in Sep 2022.I am considering contributing to an IRA for 2023. For the purposes of IRA contributions, am I still considered coverd by the retirement plan I had at work back in 2022?

[PaulaM]

It would depend on whether you have a spouse and they are covered by a retirement plan.  You do need taxable compensation to contribute to an traditional IRA or Roth IRA. See below links for reference.

Who can contribute to a traditional IRA or Roth IRA?

[dmertz]

"am I still considered covered by the retirement plan I had at work back in 2022?"

Maybe.  It depends on whether that plan uses a calendar tax year or fiscal tax year and, if it uses a fiscal tax year, when the fiscal year ended relative to when your additions to the plan stopped.  For example, if the plan year ends on March 31 and you made contributions to the plan through June of 2022, additions would have been made for the plan year ending on March 31, 2023, making you covered for 2023.  However, if the plan year uses a calendar year that ends on December 31, you would not be covered by that plan for 2023 because no additions were made for the plan year that ended on December 31, 2023.