Credit unions responded enthusiastically. According to CUNA data, from 2005 to 2015, the percentage of credit unions with community charters climbed from 17.9% to 35.8%, with percentages of all other charters – associational, occupational and multiple group – falling over the same period.

"Most, if not all, community-chartered credit unions maintain relationships with their former SEGs, and although they are no longer actually formal SEGs with a capital S, they remain lowercase select employer groups whose relationships are extremely valuable for the credit union from a marketing and community penetration point of view," Dollar, principal partner at Dollar Associates LLC in Birmingham, Ala., said.

However, the extent to which a community-chartered credit union remembers its former SEGs and keeps those special relationships alive varies widely. Some credit unions recognized the relationships' value while others abandoned their former SEGs, according to Julie Ferguson, founder of the Philadelphia, Penn.-based JRF Consulting Services.

Ferguson, a former executive for the $8 billion, Mountain View, Calif.-based First Technology FCU, advises on credit union business development and said she frequently utilizes SEG strengths in marketing and relationship building efforts.

"It comes up all the time in the context of building relationships to further membership and expand services," Ferguson explained.

Ferguson said SEGs are a strong channel that credit unions can use to introduce themselves to non-members, as well as solidify themselves as not only sources of financial services, but of expertise and advice.

"Whether they call them community partners or industry groups or employee groups, they help credit unions become a more important part of the employee's lives," Ferguson said. "Maybe a credit union jointly sponsors part of the company's weekly orientation program for new employees. Maybe a team from the credit union offers a financial education class on how to evaluate potential car loans or credit cards or student loans. Whatever it is, it furthers the relationship."

Those relationships are key, she said, because they have always been a credit union strength. Because of them, older employees of a SEG often introduce the credit union to new employees, for example. The employer's link to the credit union also prompts it to offer employees meaningful financial benefits that help reduce turnover and build satisfaction.

In addition, Ferguson pointed out, working with a SEG or former SEG helps credit unions target their marketing dollars more efficiently compared to almost any other marketing effort that targets its entire community.

Some SEG-related promotional activities cost credit unions money, such as an orientation week sponsorship or financial seminar; however, not as much as community advertising would cost in most cases, Ferguson said.

Hank Hubbard, president/CEO of the $31 million, 9,600-member One Detroit Credit Union echoed some of Ferguson's observations, explaining that One Detroit CU (formerly Communicating Arts Credit Union) neglected its SEGs when it adopted a community charter and is now working hard to renew those relationships.

The Detroit-based cooperative's state law allows for both a SEG and community charter.

"We applied for the community part as we were opening the Highland Park branch," Hubbard said. "We wanted the neighbors to be able to join. We also put most of our efforts into making an impression in the community, which was very successful. We didn't intend to, but this caused us to neglect our SEGs. As a result those relationships waned, and it became worse the more we neglected them."

He continued, "Now that we are retooling our goals for new membership, we are once again working to nurture the SEG relationships. It's an uphill battle though because we lost all of the momentum we had built up before the move to community."

Hubbard also said the credit union appreciates the relatively lower marketing expenses brought on by new member enrollment via SEGs, especially since the cooperative's launch of a membership drive this year. He also noted SEG members tend to be reliably employed and offer economic stability as a result.

Karen Rosales, president/CEO of the $229 million, Falls Church, Va.-based Arlington Federal Credit Union, said her credit union exemplifies the approach of keeping SEGs after moving to a community charter and has even added new SEGs.

"We have called them our community partners," Rosales said, adding Arlington FCU might not be typical because the cooperative worked very hard to maintain strong relationships with its roughly 100 community partners even after it adopted a community charter.

Rosales put the local group-business connection in the context of overall community awareness, which, she maintained, is strong in Arlington.

"We just moved to Arlington about three weeks ago," said Rosales, who previously lived in a nearby Maryland suburb and commuted to work. "We love Arlington and we love how much Arlingtonians love Arlington. As Arlington FCU, we wanted to be part of that love and connection."

Keeping community partner relationships strong has meant offering financial seminars, financial literacy training, special promotions and credit union orientation programs to residents and business partners throughout Arlington, Rosales explained.

To keep the connections strong, the cooperative has maintained its commitment to being a bilingual institution with Spanish-speaking staff. And recently, it moved its headquarters from the northern part of the county to the southern, which has a significantly higher percentage of Spanish speaking residents.

"Everything we do is aimed at building and keeping our connection with existing members and making new ones," Rosales said. "Our community partner groups are part of that effort too."