[See also: Filing deadlines approach for small biz tax credit]

The Congressional Budget Office estimates the credit will cost $37 billion over the next 10 years, and that taxpayers would claim up to $2 billion of credit for the 2010 tax year. But as of mid-May 2011, TIGTA reports, taxpayers have claimed only $278 million.

TIGTA says some taxpayers and tax practitioners made mistakes when completing Form 8941 to apply for the credit. That form, Credit for Small Employer Health Insurance Premiums (Form 8941), "does not contain all of the data and calculations needed to verify each step of credit eligibility."

In response to the report, Assistant Secretary for Tax Policy Emily McMahon wrote a blog on the Treasury's website, pointing out a few facts to consider about the small business tax credit. First, she says, the TIGTA data in the new report is not complete for 2010, and, having been filed on Sept. 19, 2011, is more than five months old.

Plus, many businesses file taxes in September or October, so it's possible a lot of employers had not filed returns by the time this report was compiled. McMahon says recent data indicates claims are 56 percent higher than the early figures cited in the report. "About 309,000 small businesses and small business owners received $435 million in tax credits, and we expect this number to increase as more filings are processed." 

Also, McMahon points out, businesses usually make decisions about health insurance at the start of the year, and since the credit was enacted in March 2010, many employers wouldn't have had the chance to make adjustments to qualify for the credit.

For those businesses who believe they may have qualified for the credit, McMahon notes they have a chance to file an amended 2010 return using Form 1040X, which is available on the IRS website.

Other options for small businesses that didn't get to claim the credit:

• Businesses without tax liability this year can still benefit: The Small Business Jobs Act of 2010 provided that for Tax Year 2010, eligible small businesses may carry back unused general business credits (including the small employer health care tax credit) five years. Previously these credits could only be carried back one year. Small businesses that did not have tax liability to offset in 2010 should still evaluate eligibility for the small business health care tax credit in light of this expanded carry back opportunity.
• Business that couldn't use the credit in 2010 can claim it in future years: Some businesses that already locked into health insurance plan structures and contributions for 2010 may not have had the opportunity to make any needed adjustments to qualify for the credit for 2010. So these businesses may be eligible to claim the credit on 2011 returns or in years beyond. Small employers can claim the credit for 2010 through 2013 and for two additional years beginning in 2014.

The IRS recently announced it will be boosting outreach efforts to get more businesses informed about the tax credit, including issuing public access videos like the one below.