<![CDATA[Background: Student tardiness remains a persistent disciplinary problem that disrupts classroom routines and hampers academic engagement in secondary schools, requiring structured behavioral interventions to promote measurable and sustainable behavioral change. Objective: This study evaluated the effectiveness of group counseling using behavior contract techniques in reducing chronic tardiness among high school students. Method: A classroom action research design spanning two cycles was implemented with four habitual latecoming students at SMA Negeri 18 Surabaya. Each cycle comprised planning, action, observation, and reflective evaluation. Data collection combined direct behavioral observations, semi structured interviews, and school attendance records, analyzed through qualitative descriptive synthesis. Results: Following Cycle I, tardiness decreased from seven to thirteen monthly episodes down to two to three occurrences per week. By the end of Cycle II, tardiness was eliminated completely to zero incidents as participants consolidated individual commitment to agreed behavioral targets alongside consistent positive reinforcement, clear accountability sanctions, and stringent attendance monitoring. Conclusion: Group counseling applying behavior contract strategies effectively eradicates recurrent lateness, providing an accountable model for institutional discipline management. Originality/Value: This study provides empirical and practical novelty in the field of behavioral school guidance and counseling by demonstrating the effectiveness of behavior contract group counseling in completely eliminating student tardiness from baseline frequencies of seven to thirteen times per month to zero incidents in the second cycle through positive reinforcement schemes, structured consequences, and rigorous monitoring regarding the reduction of student indiscipline within the context of at risk habitually late students at SMA Negeri 18 Surabaya, which has remained underexplored with measurable action frameworks. These findings enrich empirical evidence and serve as a strategic benchmark in developing school discipline management standard operating procedures, designing actionable behavioral contract templates for guidance counselors, and integrating action-based group counseling interventions to foster sustainable student punctuality and academic accountability.]]>
