This study is a single-arm, open-label phase Ib clinical trial testing the hypothesis that the daily use of lenalidomide will be safe and tolerable as evidenced by the rate of dose-limiting toxicity (DLT) seen during one month of reinduction/consolidation in older (≥ 60 years of age) acute myeloid leukemia (AML) patients treated after one cycle of conventional, anthracycline-based induction. (Re-induction is the prescribed lenalidomide therapy given to patients who are in partial remission/response post induction while consolidation is the same prescribed lenalidomide therapy post induction given to patients who are in complete remission).