12 CFR 208.4: Capital adequacy.

(a) Adequacy. A member bank's capital, calculated in accordance with part 217, shall be at all times adequate in relation to the character and condition liabilities and other corporate responsibilities. If at any time, in light of all the circumstances, the bank's capital appears inadequate in relation to its assets, liabilities, and responsibilities, the bank shall increase the amount of its capital, within such period as the Board deems reasonable, to an amount which, in the judgment of the Board, shall be adequate.

(b) Standards for evaluating capital adequacy. Standards and measures, by which the Board evaluates the capital adequacy of member banks for risk-based capital purposes and for leverage measurement purposes, are located in part 217 of this chapter.