Introduction: The verifi® test has been available for twin gestations through the Illumina CLIA lab since October 2013. Published studies of NIPT in twin gestations are limited to small numbers. This study summarizes clinical lab metrics of NIPT in >1000 twin gestations. Methods: Clinical lab data from twin pregnancies were reviewed. Pregnancy outcome for cases with Aneuploidy Detected (AD) or Aneuploidy Suspected (AS) result was collected following an established protocol. Results: During the study period, 1,456 samples from twin gestations were received from US and non-US sites for testing. Zygosity was not reported for most. Results were reported in 1440 cases (98.9%) with average turnaround time of 3.1 business days. Of 16 (1.1%) total cancellations, one (0.07%) was due to technical reasons. Median gestational age was 12 wks (range 10-36 wks) and mean maternal age was 35.9 yrs. Aneuploidy was detected in 27 (1.88%); 24 were T21 (1.67%) and 2 were T13 (0.14%). One case was AD for full or partial monosomy 18. Four cases (0.28%) were AS [2 T21, 1 T18, and one double aneuploidy AS T18 and AD T21]. Sex chromosome analysis, reported as presence or absence of Y chromosome, was requested in 1318 cases; Y was present in 930 (70.6%) and absent in 388 (29.4%). Outcome was available in 46.6% (14) of cases with AD or AS results. Outcome information was unavailable mainly from non-US samples. Eleven AD cases were concordant. There were 3 (0.21%) putative false positives (1 AS T21, 1 AD T21, 1 AD T13) and no known false negatives. Conclusions: This study demonstrates that the verifi® test algorithm for twin gestations shows excellent test metrics in a clinical lab setting. The patterns seen in this study are similar to our previously reported clinical lab experience for singleton gestations (see Table), providing further support for the utility of NIPT in twin pregnancies. Future studies analyzing pregnancy outcomes in twin gestations are needed to better define clinical test performance of NIPT in this population.