The Alternative Learning System (ALS) Accreditation and Equivalency (A&E) examination resumed in January 2025 after a five-year hiatus, presenting unprecedented preparation challenges for Schools Division Office (SDO) Makati City. This action research investigated how intensive familiarization and mock testing could improve ALS learners' performance in the A&E examination within a constrained 45-day preparation period. The study employed a mixed-methods action research design involving 398 ALS learners across 30 learning centers and 45 teachers. The intervention utilized the "ALS 45 Days Challenge" framework, implemented through five phases: initial planning and diagnostic assessment, curriculum development, structured review classes, intensive familiarization with mock testing, and final examination administration. Data collection included baseline diagnostic assessments, weekly mock examinations, teacher reflection logs, and performance tracking across six learning strands. Quantitative analysis employed descriptive statistics, paired t-tests, and ANOVA, while qualitative data underwent thematic analysis. Results showed a combined success rate of 62.68%, with 40.61% regular passers and 22.07% conditional passers among 426 test-takers (89.68% participation rate). Junior high school learners achieved higher success rates (66.57%) compared to elementary learners (48.94%). Center performance varied significantly from 14.29% to 100.00%, indicating the importance of implementation fidelity. The findings demonstrate that systematic, intensive preparation strategies can produce substantial results despite severe time constraints, providing a replicable framework for rapid educational intervention in similar contexts.