Can IRS extensions be e-filed?
Yes, through TurboTax Easy Extension, available March 20.
If you need to file your extension before then, it'll have to be paper-filed.
TurboTax Easy Extension will shut down in mid-June, which is the extension filing deadline for U.S. citizens or resident aliens who were out of the country on the April 18 deadline.
Yes, but the deadline for tax year 2016 returns has passed. The deadline to file an extension was April 18 for domestic taxpayers and June 15 for taxpayers outside the country.
TurboTax Easy Extension for tax year 2017, which lets you e-file your extension for free, will launch in mid-March of 2018.