The present disclosure provides a transgenic corn comprising event MON87403 that exhibits increased grain yield. The disclosure also provides cells, plant parts, seeds, plants, commodity products related to the event, and DNA molecules that are unique to the event and were created by the insertion of transgenic DNA into the genome of a corn plant. The disclosure further provides methods for detecting the presence of said corn event nucleotide sequences in a sample, probes and primers for use in detecting nucleotide sequences that are diagnostic for the presence of said corn event.