Details Found in IRS Explanation Issued Wednesday; $20,000 Figure Based on a Family of Four.   In a final regulation issued Wednesday, January 30, 2013, the Internal Revenue Service (IRS) assumed that under Obamacare the cheapest health insurance plan available in 2016 for a family will cost $20,000 for the year.   Under Obamacare, Americans will be required to buy health insurance or pay a penalty to the IRS.  The news was reported by Huffington Post, CNS News, Catholic News, Investment Watch, Economonitor, Naked Capitalism, Investor Village, and more.    The Journal of Accountancy offered detailed analysis of the new regulations, and NPR weighed in…