I am 25 years old.
I took a 2017 Disaster Distribution from a Traditional 401(k) account in 2018 due to hardship due to Hurricane Irma.
Do I need to repay it back (i.e. is it mandatory to be repaid) to an eligible retirement account in the future in order to avoid the 10% penalty?
I understand that I have a choice to make a repayment if I choose, but I am choosing not to make a repayment, and therefore, will there be any unfavorable tax repercussions due to that (e.g. paying any penalties?)
In other words, the literature in the Form 8915B instructions states that the tax-payer has a choice to make a repayment but does not clearly state that the tax-payer has a choice not to make a repayment.
Repayment is not necessary to avoid the early-distribution penalty. Simply qualifying as a disaster distribution eliminates the penalty. If you don't repay it, it is subject to ordinary income tax even though it is not subject to penalty.
General "hardship" does not qualify the distribution as a disaster distribution. Provided that your main home was in the qualified disaster area for Hurricane Irma, for this distribution to be a qualified disaster distribution you had to have suffered as a result of Hurricane Irma an economic loss due to loss or damage to real or personal property, loss related to displacement from your home, or loss of livelihood due to temporary or permanent layoffs. Perhaps one of these is what you meant by "hardship."