This cross-sectional study examined abbreviated Test of Memory Malingering (TOMM) indices, including Trial 1 (T1) and errors on the first ten items of T1 (TOMMe10), and their respective concordance to assess whether the administration of Trial 2 (T2) provides incremental value. Pass/fail concordance between TOMMe10, T1, and T2 was examined among a diverse mixed clinical sample of 414 neuropsychiatric patients. Of those who failed TOMMe10 or T1, 74% and 77%, respectively, went on to fail T2. For those failing TOMMe10 and T1, 82% failed T2. For those failing T1, 0% passed T2 if T1 was below 30, 13% passed T2 if T1 was 30–34, and 33% passed T2 if T1 was 35–39. Further, 60% of those who failed T1 with scores below 40 also failed two or more independent performance validity tests (PVTs). Using currently accepted practice standards of two or more independent PVT failures as indicative of invalid performance, 93% of those with T1 scores below 30, 80% of those with T1 scores of 30–34, 70% of those with T1 scores of 35–39, and 41% of those with T1 scores of 40–41 failed at least one other independent PVT and, thereby, would be classified clinically as demonstrating invalid neuropsychological test performance. Collectively, results indicated TOMM T2 administration is unnecessary with T1 scores below 35 or above 41. Patients with T1 scores of 35–41 had relatively lower rates of invalid performance on T2, although the implications of potential T1/T2 discrepancies for overall validity status remain unclear.