Additionally, individual federally insured credit unions could be required to maintain higher levels of risk-based capital to address unique supervisory concerns raised by the NCUA, according to the rule's Board Action Memo.

The risk-based capital proposal for natural person credit unions would replace the current risk-based net worth risk-weighting method, putting them more in line with the NCUA's risk-based capital requirements for corporate credit unions, the NCUA said, as well as capital requirements at the FDIC, Federal Reserve and Comptroller of the Currency.

The proposed risk-based ratio would be determined by the percentage of a credit union's net worth available to cover losses, divided by the credit union's defined risk-weighted asset base, the NCUA said.

NCUA estimates that more than 90% of affected credit unions – approximately 2,237 institutions – would be in compliance with the proposed rule, based upon June 30, 2013 call report data.

However, 189 credit unions would experience a decline in their PCA classification from well capitalized to adequately capitalized, and 10 well-capitalized credit unions would experience a decline to undercapitalized status.

The NCUA estimated that, collectively, those 10 undercapitalized credit unions would need to retain an additional $63 million in risk-based capital to become adequately capitalized, assuming no other adjustments.

The capital requirements and PCA supervisory actions for “new” credit unions and credit unions with fewer than $50 million in assets would remain largely unchanged.

The rule was given a longer-than-usual comment period of 90 days.

In July 2013, NCUA Chairman Debbie Matz said the current 7% net worth requirement would remain the base requirement in a proposed risk-based capital rule, as defined by the Federal Credit Union Act. Credit unions with more than $50 million in assets would be subjected to higher risk-based net worth requirements.

Board Member Michael Fryzel was seeking a balanced approach to the rule in November 2013, advocating for a new standard that was not overly stringent or overly permissive.

“I advocate 'right sizing' NCUA's risk-based capital rules. One of the undeniable lessons learned from the crisis is the value of a financial institution's capital—capital that is ample, durable and can be readily deployed to shore up a balance sheet under duress,” he said.