What's more, the repeal of Obamacare is expected to increase health care premiums by as much as 25%, according to the Congressional Budget Office, the nonpartisan office within the legislature that produces research and analysis of proposed policies. If that occurs, it may be too much for many small credit unions to sustain, forcing some to consolidate. Huge jumps in health care insurance may even affect the competitiveness of some midsize credit unions that would have to divert more resources for employee insurance coverage instead of investing in products and services for members.

"The increases in health care premiums is a huge issue for the industry and is certainly a cause for mergers," Glenn Christiansen, owner of the CEO Advisory Group in Kent, Wash., said.

Based on his analysis of NCUA data, he noted that two-thirds of credit unions failed to grow at all between 2008 and 2013 in part because of benefit cost escalation, which included healthcare insurance.

Some credit unions, however, have successfully managed to grow loans and assets despite rising benefit costs and expect to do the same whenever Trumpcare rolls around.

Cindy L. Swigert, vice president of human resources for the $340 million Day Air Credit Union in Kettering, Ohio, said many trusted experts think the Obamacare repeal and Trumpcare replacement will move much more slowly than some have professed. That will give credit union executives opportunities to lobby their elected representatives when the details of a Trump replacement plan surface.

"That would be the channel we would take as this unfolds. For now, we are working closely with our broker and other legal resources to stay on top of this," she said. "Once more details of Trumpcare are known, we will be prepared to weigh in through our representatives after understanding the proposed impact to our employees and our membership."

Lisa Asadourian, vice president and chief engagement officer for the $400 million Nutmeg State Financial Federal Credit Union in Rocky Hill, Conn., is also taking a wait and see position.

"We're hopeful that any changes will be positive," she said. "I guess what they are proposing is a promise of fewer problems, but nothing is definite. It seems there are a lot of conversations about Obamacare and Trumpcare, but it doesn't seem like there's an actual viable option for replacement."

Nevertheless, organizations such as the Kaiser Health Foundation are monitoring the latest health insurance news coming out of the White House and Congress and what could be coming down the road.

"There are, at least, some things that we know and some common themes that have emerged in this debate," Larry Levit said, who is an SVP for special initiatives and co-executive director of KHF's program for the study of health reform and private insurance.

Once the budget reconciliation process in the Congress is completed, it is expected to immediately repeal the Obamacare mandates for employers with 50 or more employees to provide health insurance and for individuals to buy health insurance. All of Obamacare's tax increases are also expected to be repealed immediately.

While there are a number of major replacement proposals, there hasn't been any one that Republicans have rallied around yet. Moreover, many of them are privately concerned about the political ramifications of repeal and replace.

Levitt noted, for example, there seems to be bipartisan support to allow dependents to remain on their parent's plan up to the age of 26 and to require insurance companies to provide coverage for people with pre-existing conditions.

What may complicate matters, however, is President Donald Trump's recent executive order regarding Obamacare.

"The executive order does not have any immediate effects on the ACA or grant any new powers to federal agencies, but it includes signals, a direction that the new administration intends to take with respect to the ACA," Levitt explained. "Two important provisions in that executive order are, number one, to waive or delay a variety of fees, penalties and regulations that are a part of the ACA. Again, none of those fees, regulations or penalties are waived or delayed immediately. It simply directs agencies to move in that direction. It also asks federal agencies to exercise all authority and power they have to provide greater flexibility to states."

Moreover, while Obamacare's 10 categories of health care benefits that insurers currently are required to provide cannot be waived for now, there is substantial authority for the Trump administration to allow limits on these benefits including eliminating the requirement for no-cost coverage, according to Levitt.

The 10 categories that could be affected by Trump's executive order include preventive and wellness services, doctor visits and outpatient care, emergency services, hospitalization, prescription drugs, laboratory services, maternity and newborn care, mental health services, rehabilitative services and devices, and pediatric services.

This means there could be fewer health care benefits for employees and their families and more out-of-pocket costs for them if limits are implemented.

For credit unions, the rising costs of health care premiums mean fewer dollars for other operational expenses that support growth.

Christiansen, of the CEO Advisory Group, noted that even though credit union employees saw an average compensation growth of about 3% between 2008 and 2013, some of this compensation increase was driven by rising health care insurance premiums.

Health care premiums far exceeded the inflation rate of 1.6% between 2008 and 2013. Family health care premiums increased by an annualized rate of 5.2%, according to the Kaiser Family Foundation Employer Health Benefits survey.

Additionally, according the Kaiser survey, employers are paying a greater share of health care premiums than in past years. Employee contributions for both single and family coverage have been growing at 6.7% and 6.4%, respectively.

"Consider the impact an average health care premium of $5,900 for a single person and $16,350 for a family has on credit union compensation strategy," Christensen said. "For a small credit union, this represents a significant portion of the organization's total compensation. As a result, these credit unions must compromise raises, retirement contributions, and richness of health plans and/or employee contributions to these plans."

Because this trend of rising health care premiums is expected to continue, it will keep adding pressure on small credit unions and some midsize credit unions to explore a merger option, and for some, it may be the only option.

"The earnings for so many credit unions really don't allow them to increase their compensation expense, so what are they going to do with respect to health care if premiums keep increasing for them?" he asked. "They are going to have to make some tough choices like reducing head count, reducing hours, or certainly the ability to continue to provide salary increases is going to be very difficult for most credit unions to do."

And that means the pace of mergers may substantially increase over the next few years, not just for small credit unions but for larger ones as well.