Aren't you better off putting some money into a TFSA, trying to grow it there, then taking if out to pay the extra taxes at year end? If you have the same growth in the RRSP then you'll pay tax in the gain at your marginal tax rate when taking it out to pay your tax bill. Only benefit I see is if your deduction can allow you to drop down into the next lower tax bracket (or if you do the RRSP route, take the refund and invest it inside a TFSA, then use the principal/gains (if any) to pay your incremental tax bill). Plan at this time of the year for tax time in 2017 and you'll keep more money in your pocket at the end (and less to Justin and Kathleen unless you want to help them pay down their bills like Kathleen is asking us to do).