Obamacare is about to collide with the U.S. tax-filing season,adding frustration for millions of taxpayers trying to figure out how to comply and how much they will owe the government.Tax filing for 2014 opens Jan. 20. The biggest change for most taxpayers is on Line 61 of Form 1040: a box to check if you have health insurance and a tax to pay if you don’t. Millions who received insurance through Obamacare’s exchanges will have a more complicated set of calculations to complete.Have Obamacare? You May Need It to Navigate Tax-Filing Headache – Businessweek.