TAM 04 O-16L (Reg. No. GP-926, PI 659441) upland cotton (Gossypium hirsutum L.) germplasm line was developed by the Cotton Improvement Laboratory, Department of Soil and Crop Sciences, Texas AgriLife Research, Texas A&M University, and released in 2009 as part of an ongoing effort to create germplasm with combinations of improved fiber quality parameters, especially upper half mean length (UHML) and fiber bundle strength (FBS). TAM 04 O-16L exhibited high volume instrument UHML greater than 32.0 mm in five of six location-years, which is the minimum UHML to be classified as extra-long upland cotton according to Cotton Incorporated (Cotton Incorporated, 2009), and in one test TAM 04 O-16L exceeded the minimum UHML of 34.8 mm for pima (G. barbadense L.). Fiber bundle strength exceeded that of 'Deltapine 491' and 'FiberMax 832', both of which exhibit excellent FBS among current non-Acala upland cultivars.