401k Roth Deferral?

[jasminegeekface]

I recently found out that my company's 401k allows me to make regular pre-tax contributions as well as Roth contributions, and the latter is a form of retirement savings that I'm not wholly familiar with. Could anyone here explain what hypothetical reasons someone could have for choosing to make Roth contributions versus pre-tax contributions, or to make a mix of both? Are the factors similar to a tIRA vs Roth IRA, i.e. tax rates expected to be lower/higher later in life, etc? I'm assuming the total contribution between the two types can still only add up to $18k max; is that correct?

Thank you in advance!

[ZiziPB]

You are correct on both counts:  the $18K annual limit is a combined limit and the considerations revolve around tax bracket you are in now versus where you expect to be in retirement.  I think as a general rule of thumb, if you are in the 15% bracket, people recommend Roth, if 25% or above, traditional pre-tax.

[Gone Fishing]

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