Reviewed or updated January 17, 2021
It’s OK to make regular contributions to a Roth IRA you established by converting a traditional IRA.
For a while after the Roth IRA was created there was some confusion about whether you might be creating a problem if you made regular contributions to a conversion Roth IRA, but a law passed long ago cleared up that situation. You can use the same Roth IRA for both purposes, avoiding the extra paperwork, and perhaps added fees, involved in maintaining two accounts.
Under prior law, there was potentially a small advantage in avoiding regular contributions to a conversion Roth IRA until after the end of the period in which you’re allowed to undo the conversion. The 2017 tax law did away with the ability to undo post-2017 conversions, eliminating this planning consideration.