"Rollover" for type to type, is not taxable and not reportable. Example: 401(k) to Trad IRA, or Roth 401(k) to Roth IRA.

Anything that changes the nature of the funds is a taxable conversion. 401(k) to Roth IRA or Roth 401(k), for instance. Trad to Roth is a taxable conversion.

Rollovers (like to like) that miss the deadline are failed rollovers, and would be taxable for sheltered account types.

And once someone creates more taxable income, that would affect all other eligibility such as Roth contributions, credits that are AGI or MAGI limited.