Since the onset of formal operations, NDACC (formerly NDSC) has designated several specific instrument types as official measurement capabilities. These are: Dobson / Brewer Spectrometers, Fourier Transform IR Spectrometers (FTIRs), Lidars (temperature, ozone, and aerosol), Microwave Radiometers, and UV/Visible Spectrometers. Balloon Sondes (ozone and aerosol) and UV Spectroradiometers were added shortly after the Network became operational. The Network strives to maintain the operation of as many of these instrument types within the various latitude regions as possible. As NDACC has matured, its measurement and analysis emphases have broadened to encompass issues such as the detection of trends in overall atmospheric composition and understanding their impacts on the stratosphere and troposphere, and establishing links between climate change and atmospheric composition. These challenges require an expansion of measurement capabilities, particularly in the area of some key climate parameters. Thus, after careful consideration and evaluation by the various NDACC Instrument Working Groups, the Steering Committee approved two new instrument types for NDACC designation: Raman Lidars for profile measurements of water vapor in the troposphere and across the tropopause, and Water Vapor Sondes (cryogenic frostpoint hygrometers and Lyman-ahygrometers) for profile measurements in the troposphere and stratosphere. Data from both instrument types soon will be available in the NDACC data archives.