A. Assume you are not procrastinating the tax filing, rather you have a more complex return to file, you can buy yourself more time by filing a Form 4868 by mail or electronically, in this way, you will get an automatic six-month extension. You can submit online for free via IRS' Free File program even if you earn more than the threshold for free tax help (income $64,000 or less).
Getting an extension is better than filing now than amend later. With an extension, you can avoid a costly failure-to-file penalty of 5% of your unpaid taxes per month, up to a max of 25%.
However, even with an extension, you must pay what you owe by April 18, 2017 to avoid interest (currently 4%) and a late-payment penalty of 0.5% of your unpaid taxes per month. If you don't have enough money, you can apply for an online payment agreement from the IRS as long as you owe $50,000 or less. If you can pay within 120 days, you automatically qualify for a no-fee and short-term plan.