The $12 billion record is a noteworthy milestone considering that credit unions have provided nearly double the amount of funds to small business that Bank of America claims to have done in its new ad campaign, Becker said.

As proof, Becker pointed to an SBA report released last year that showed credit unions picked up the business lending slack over a 24-year period when banks scaled back.

While credit unions devoted more of their assets to small business loans since the 1980s, banks went in the other direction, according to the SBA report. The growth rose gently during the 1990s and much more rapidly through 2010. In contrast, banks devoted a fairly steady share of their assets to SBLs until the 2000s, when their share fell rather substantially, the data showed.

While credit unions would like to do more to help their small business members, the current 12.25% cap on MBLs has limited lending efforts, NAFCU said.

NAFCU, CUNA and others are advocating for passage of the Small Business Lending Enhancement Act (S. 2231/H.R. 1418), which would raise the cap to 27.5% of assets.

"The banks are saying a bunch of malarkey," Becker said about bank groups that have pushed hard against raising the MBL cap. "We've been doing business lending since 1934. The cap was arbitrarily put in place in 1998. We need to move forward on this."

Sen. Mark Udall (D-Colo.), who has been a strong advocate of raising the MBL cap by way of his proposed legislation, recently marked National Small Business Week by recognizing Colorado's small businesses.

"I will continue to work with my colleagues to foster a business environment that supports entrepreneurship and innovation, from passing production tax credits that prop up a burgeoning wind energy sector to raising an arbitrary cap on credit union lending to give Main Street businesses access to capital," Udall said in a statement.

Brett Thompson, president/CEO of the Wisconsin Credit Union League, suggested banks have the market cornered when it comes to small business lending.

"This is not a credit unions vs. banks issue," Thompson wrote in the Milwaukee Biz Blog. Banks control 95% of the country's small business lending market."

Thompson penned the opinion piece to promote proposed legislation that would raise the member business lending cap from 12.25% to 27.5%.

"Clearly, passage of this legislation would have a tremendous impact, particularly at a time when small businesses continue to be hurt by their inability to gain access to the credit they need to grow," Thompson said.

The other billion in the news is the potential $13 billion in freed-up capital that the new cap would make available on top of creating 140,000 new jobs nationwide, Thompson wrote. In Wisconsin, the legislation would create $408 million of new credit and add 4,437 jobs in the first year alone, he added.

"Notably, Wisconsin credit unions have had a lower loss rate than banks on business loans for over a decade," Thompson said.

When asked what will help credit unions keep the $12 billion business lending momentum going, Becker said he is more concerned about the downside.

"Keeping the cap where it's at would likely curtail lending or it would go flat," he offered, adding the new threshold can add 120,000 jobs to the economy in the first year.