Objectives: This study aimed to estimate the prevalence of loss to follow-up (LTFU) among tuberculosis (TB) patients in Indonesia and to identify associated factors. Methods: This study analyzed data from the 2022 Tuberculosis Information System in Indonesia. A total of 71,665 drug-sensitive TB patients were included in the analysis. Age, sex, employment status, diagnosis type, human immunodeficiency virus (HIV) status, diabetes mellitus, TB type, mode of treatment, treatment standard, referral status, and type of residence. Categorical variables were analyzed using chi-square tests, followed by multivariable logistic regression to identify confounder-adjusted independent predictors of LTFU. Results: The prevalence of LTFU was 18.4%. A higher likelihood of LTFU was observed among older adults aged ≥65 years (adjusted-prevalence-odds-ratio [aPOR], 1.862), men (aPOR, 1.187), unemployed individuals (aPOR, 1.136), non-referred patients (aPOR, 1.547), patients with HIV (aPOR, 3.712), and those obtaining TB drugs out of pocket (aPOR, 4.998). The strongest predictor was receipt of non-standard treatment, which was associated with a markedly increased likelihood of LTFU (aPOR, 26.912). In contrast, rural residence demonstrated a protective association (aPOR, 0.610). All associations were statistically significant (p < 0.001). Conclusion: This study highlights a substantial burden of LTFU among TB patients in Indonesia, with nearly one in five patients discontinuing treatment. Multiple sociodemographic and clinical factors—particularly non-standard treatment, non-referral status, and HIV co-infection—were strongly associated with LTFU, underscoring gaps in the TB care continuum. These findings emphasize the need for targeted, patient-centered interventions, strengthened referral pathways, improved communication, and enhanced care coordination to reduce LTFU in high-risk groups. © 2026 Korea Disease Control and Prevention Agency. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).