I already have a traditional IRA (rollover from former employer's 401(k)) and my current employer doesn't offer a retirement plan, so I'd been funding a Roth IRA up to the maximum allowed each year since I began with them over five years ago. I've not made any contributions to the rollover IRA since then, I've just been letting it earn dividends.
This tax year though (2019) I'm not eligible to make the full contribution amount, so I corrected it by removing the excess + earnings and adding it back as a contribution for the current tax year (2020). I've also lower my automatic contribution from my bank account so that 2020 will have roughly the amount allowed last year, to reduce the excess.
I'm now trying to figure out what to do with the money I would have put into the Roth this year. I read that its possible to make non-deductible contributions to a traditional IRA, but it also seems that this might be limited due to my income as well; or perhaps I'm only disallowed from making deductible contributions, I'm not clear on this point.
I didn't think it'd be relevant, but my wife does have, I believe, a 403(b) plan from her employer, and I don't believe she contributes to it.
Would it be allowed to make non-deductible contributions to a traditional IRA (not my rollover IRA), and what would be the maximum allowed? If that's not possible, what would be the next best investment option? I have no other investments currently except the IRAs.