A recommended rule may emerge as early as this month. It is not clear whether it will require advisors merely to have a continuity plan in place to address unexpected illness or death or mandate a more comprehensive succession plan that addresses investors' interests when advisors retire.

Significant data have emerged showing that vast sums of retirement money are being managed by financial professionals who themselves are nearing retirement.

In 2012, research from Cerulli showed $2.3 trillion in assets is being managed by advisors who are 60 and over. Other estimates project that $4 trillion in client assets will have to be transitioned to the next generation of advisors over the next decade.

Yet despite those realities, formal succession planning does not seem to be high on advisors' list of things to do.

Some studies put the number of advisors with a succession plan in place at 25 percent. Others suggest it's even fewer.

The reasons for such low adoption vary. One theory suggests many advisors don't plan to retire at 65. While the industry may be graying—43 percent of advisors are over 55, according to Cerulli—it's still populated by professionals who tend to be uniquely driven and passionate about what they do, particularly in the case of advisors who have grown their own firms organically.

Whether or not advisors expect to work beyond typical retirement age because they want to, developing an internal strategic succession plan can be more than a protection against infirmity or a way to pass on wealth to heirs. It also can be a way to incentivize greater growth and ensure that clients will have access to top-level advisory talent.

Angie Herbers, co-founder of Kaleido Inc., a San Diego-based consultancy that helps advisors grow their businesses, is among those who think the right type of succession plan can create a more efficient, profitable practice and ultimately mean more money for both the sellers of a firm and the staff who buy them out.

"Succession isn't just about how to transfer a company," Herbers wrote in a study she published comparing different succession models. "It is about building career tracks, training the next generation of talent, hiring and retaining top talent, creating incentive programs that work and developing a solid organizational structure."

Herbers describes an advisory industry that often is subject to short-sighted succession strategies based on merger and acquisition models in other industries, which don't take into advisory firms' idiosyncrasies, like recurring revenue streams.

She also cautions against what she says is a tendency for both advisor sellers and the employees buying them out to focus too much on the firm's valuation.

"While the buyout value of the firm is certainly a factor in a succession, it's not nearly as important as many buyers and sellers seem to think," Herbers said.

In the absence of a well-structured deal, or the right incentives to keep the firm growing over the buyout period, the valuation number is relatively moot, she said.

Herbers cited the example of a deal that requires the selling principal to take a salary cut over the term of the buyout—an indication of a deal that is "not viable," according to her.

Even if the firm is valued at an attractive rate to the selling advisor, in taking a pay cut, he or she stands to lose a lot of money over the term of the buyout, which can often be 10 years or more.

"By focusing on valuation, rather than the far more important deal terms and incentives to grow the firm, both owners and junior advisors can lose millions of dollars," Herbers wrote.

While there is no template that will work for every advisory firm, in the end, the key to financing an internal succession plan is growing the firm substantially.

That takes the right incentives for all involved in the deal, and as Herbers writes, it also may take time, as in some cases, extending the term of the buyout is necessary to maximize value for all.