Objectives This study revised the Korean Medication Algorithm Project for Bipolar Disorder 2018 for rapid cycling. Methods Questionnaires to survey the expert opinion of medication for rapid cycling were completed by a review committee consisting of 87 Korean expert psychiatrists. The experts’ opinions were classified into three categories based on the lowest category in which the confidence interval fell (6.5≤ for first-line, 3.5≤ for second-line, and 3.5> for third-line treatment). Results The first-line treatments were a combination of mood stabilizers and atypical antipsychotics, atypical antipsychotics monotherapy, or mood stabilizer monotherapy. Furthermore, a mood stabilizer with lamotrigine therapy and an atypical antipsychotic with lamotrigine combinations was the first-line treatment for a depressive episode. The first-line medications in all episodes were valproate, lithium, quetiapine, olanzapine, and aripiprazole. Risperidone was the first-line medication in manic episodes and mixed states, and lamotrigine was the first-line medication for treating depressive episodes. Conclusion Compared to the surveys in 2018, the preference for atypical antipsychotics and lamotrigine has increased, and the modalities as a second-line treatment are more diversified.