Abstract This paper examines a prior condition in decision-making that existing models assume but do not specify: the formation of alternatives as such. We introduce the construct of decidability to name the structural condition under which selection expresses a choice rather than the continuation of behavior, and we identify holding as the mechanism that preserves this condition under constraint. Decidability requires the stabilization of recognition, the availability of relevant features, and the preservation of alternatives as differentiated possibilities; holding sustains these elements through pause, reassessment, micro-adjustment, and embedded modulation, even where temporal compression makes its operations invisible. The framework is examined through 24 micro-events across six domains (painting, aviation, surgery, musical improvisation, high-stakes poker, and open-outcry trading), coded along six structural dimensions and independently validated. The pattern is consistent. Where holding is present, decidability forms. Where it is absent, action proceeds without the formation of alternatives. Under temporal compression, holding persists in reduced form, corresponding to partial decidability rather than its absence. These findings establish a structural distinction between choice, behavior, and outcome that does not depend on retrospective intention or outcome quality. Actions formed under decidability may fail; actions that bypass decidability may succeed. The framework further shows that decidability is not solely an individual capability but a property of the systems in which action occurs, with implications for organizational design, leadership under constraint, and the conditions under which adaptive choice remains structurally possible. The capacity required at the point of decision is not generated at that point. It is sustained into it. Keywords: Decidability; decision-making; choice formation; holding; sensemaking; situation awareness; recognition-primed decision making; real-time decision making; micro-level analysis; action under constraint; organizational design; adaptive capacity; leadership; decision processes