91 Y-STR loci tested to boost core loci discrimination. UHD multiplex co-amplifies 14 non-core loci robustly. UHD outperforms PowerPlex Y and Yfiler in mixed African American and Caucasian samples. UHD plus Yfiler discriminates 100% of 572 males. UHD recovers full profiles from male/female DNA mixtures. UHD stable in environmentally compromised blood. UHD obtains complete profiles from post-coital cervicovaginal swabs with 3ng sperm DNA. UHD works in mock casework samples with excess female DNA. UHD increases haplotype diversity beyond commercial kits. UHD suitable for forensic casework, evolutionary genetics, and genealogy.