If all goes according to schedule, there may be some clarity by the end of June, at which point the Supreme Court will render a decision in a case brought before it by the National Federation of Independent Business and 26 state attorneys general challenging the law's constitutionality. Among the items that could be affected is a credit for small-business employers who pay at least one-half the cost of health insurance coverage for their employees. If the law stands, it is still likely that the initiative will be altered. In November, the Treasury Inspector General for Tax Administration issued a report that found that the volume of claims for the credit has been low despite IRS efforts to inform 4.4 million taxpayers who could potentially qualify for it. As of mid-May 2011, slightly more than 228,000 taxpayers had claimed the credit, for a total amount of more than $278 million. The Congressional Budget Office had estimated the credit would cost $37 billion over 10 years and that taxpayers would claim up to $2 billion of credit for tax year 2010. In response, the IRS has announced plans to conduct focus groups to determine why the claim rate was so low and may take steps to better inform businesses and encourage participation. Congress and the IRS may propose an overhaul of the way the credit is implemented. Also on the table (for all taxpayers) is a 3.8% Medicare tax on investment income that is slated to go into effect in 2013. Small businesses will also be anxiously awaiting news on potential changes to the estate tax, with some advocates arguing that higher rates can be blamed for family-owned businesses forced into dissolution due to tax bills that arise because a deceased owner's includes business assets. -- Written by Joe Mont in Boston. >To contact the writer of this article, click here: Joe Mont. >To follow the writer on Twitter, go to http://twitter.com/josephmont. >To submit a news tip, send an email to: email@example.com.