If you had health coverage under both employer and marketplace, you may be in the late April returns extended until October, 2015 as there will not be sufficient information available to file an error free return. Hopefully your employer will distribute the required 1095C early; however, employee notifications have also been extended and may not arrive in January or February or even March or even April or even May.
The premise for extending employer filings with the IRS as well as with employees is that employers would have more time to calculate and revise affordability reporting so there are reduced revisions and matching errors occur upon individual tax return efile. I would expect this will result in delayed refunds for folks having any gaps or marketplace coverage.
Please note that due to the December 18th legislation, efile for individuals may be delayed again this year