If you obtained a filing extension for your personal 2015 income tax return and have not yet filed, today is the deadline for getting it in; you can still e-file the return. If you fail to file by today, you will owe a late filing penalty; no additional extensions can be granted. Those who had income below the filing threshold but who claimed the premium tax credit to pay for health coverage through a government exchange nonetheless must file a return or risk credit ineligibility for 2017. For self-employed individuals, today is the last day to fund a qualified retirement plan for 2015. Plans must have been set up by the end of 2015 to accept contributions for that plan year. Exception: You can set up and fund a SEP plan before the end of today if you are filing your 2015 return today on extension.