- October 17 – Deadline for filing your 2015 individual tax return if you requested an automatic six-month extension of the April deadline.
- October 17 – If you converted a regular IRA to a Roth in 2015 and now want to switch back to a regular IRA, this is the deadline to do so without penalty.
- October 17 – This is the last day to fund your Keogh or SEP plans if you requested an extension of time to file your tax return.