What are the differences between a Roth contribution and an after-tax contribution, and how do they impact my retirement savings strategy?

The main difference between a Roth contribution and an after-tax contribution is how they are taxed. With a Roth contribution, you pay taxes on the money before you contribute it, while with an after-tax contribution, you pay taxes on the money when you withdraw it.

The impact on your retirement savings strategy is that Roth contributions allow for tax-free withdrawals in retirement, potentially saving you money in the long run. After-tax contributions may provide some tax benefits now, but you will have to pay taxes on the earnings when you withdraw them in retirement. Deciding between the two depends on your current tax situation and future financial goals.