Approximately 300 reservoirs in the New Mexico part of the Permian Basin have cumulative production of more than 1 million bbls oil (MMBO). These 300 reservoirs had produced a total of 4.5 billion bbls oil at the end of 2000. The reservoirs have been grouped into 17 plays based on geologic parameters, including reservoir stratigraphy, lithology, depositional environment, tectonic setting, and trapping mechanism. There are 10 Permian plays that have a cumulative production of 3506 MMBO, two Pennsylvanian plays with a cumulative production of 424 MMBO, three Siluro-Devonian plays with a cumulative production of 440 MMBO, and two Ordovician plays with a cumulative production of 86 MMBO. During 2000, 40 MMBO were produced from the Permian plays, the Pennsylvanian plays yielded 6.4 MMBO, the Silurian-Devonian plays yielded 1.4 MMBO, and the Ordovician plays gave up 0.35 MMBO. Most production in the basin has been obtained from reservoirs located on the Northwest Shelf and on the Central Basin Platform. There are 13 plays productive from shelf, platform and ramp settings. These 13 plays have produced a cumulative total of 4231 MMBO and 39 MMBO during 2000 from 249 reservoirs. In contrast there are four plays that are productive from reservoirs deposited in basinal settings. These four plays have 50 reservoirs with more than 1 MMBO production and produced a cumulative total of 226 MMBO; 9.0 MMBO were produced from the basinal plays during 2000. A wide variety of advanced management techniques have been applied in the Permian Basin in order to enhance or stimulate production from already discovered reservoirs. Waterfloods have increased recovery and produced substantial volumes of oil in both shelf and basinal reservoirs. Pressure maintenance projects have increased production in solution gas drive reservoirs. In some cases, horizontal drilling has been successfully applied to produce oil not in communication with vertical wells in horizontally compartmentalized reservoirs or to produce oil that was unswept by waterfloods in old, mature reservoirs. Other old reservoirs have benefited from completions in bypassed pay that remained unproduced behind casing. Yet other reservoirs did not attain full field development for years after discovery because development was undertaken on the basis of misconceptions regarding trapping mechanism. In yet other cases, exploratory objectives were overlooked in favor of drilling targets in other stratigraphic units. It appears that advanced reservoir management techniques have been successful in many plays but not always widely applied, leaving potentially productive oil in the ground.