NE-CAT operates two mature, state-of-the-art beamlines optimized for macromolecular crystallography at the APS. The goal of the Macromolecular Crystallography (MX) Core is to provide user access to these facilities, to maintain the facilities, and to make improvements so that NE-CAT remains state-of-the-art. The most important component for providing access is user support and training. User support requires about four FTEs, made up by contributions from eight staff scientists. About two FTEs are devoted to user training and outreach, and about two FTEs, to beamline hardware and software maintenance and development. The MX Core provides access 24/7, either on-site or on-call, for both on-site and remote users. It maintains hardware and software for accurate, high speed data collection, including crystal screening, SAD/MAD phasing, molecular replacement phasing, high resolution data acquisition, and methods for obtaining data from challenging ("pathological") crystals. NE-CAT provides stable, small X-ray beams for a variety of microbeam applications. Special scanning techniques allow the user to ameliorate crystal damage, locate crystals in opaque media, and assess the quality of localized regions within larger, inhomogeneous crystals. The MX Core also provides full access to RAPD, NE-CAT’s automated data collection and analysis software. The MX Core will maintain existing beamline hardware and software at peak performance, through a well-defined, long-term plan for providing routine maintenance of motion control systems, critical vacuum and ultrahigh vacuum pumps, and monochromator cryopumps. The MX Core will also maintain computer clusters, beamline and data analysis computers, disk storage systems, and network infrastructure. Certain improvements will be essential for keeping NE-CAT facilities at state-of-the-art. These fall into three areas: (1) beamline optics and instrumentation, (2) computing infrastructure, and (3) RAPD software. Plans for beamline optics include installation of a ganged channel-cut monochromator on 24-ID-C and installation of new MD3 goniometers on both beamlines. These modifications and improvements are compatible with the APS upgrade, scheduled to begin 2023. The upgrade program includes 12 months without X-rays, which presents a superb opportunity for rebuilding our nearly 20-year- old beamlines for another 20 years of operation. Computing upgrades include addition of faster nodes to the compute clusters and additional disk storage for data collection, and upgrades. We will implement new externally developed data processing and analysis routines in RAPD, to maintain state-of-the-art techniques, and we will develop new methods to support developments in serial microcrystallography and fully automated crystal screening and data collection. Finally, will develop methodology for routine serial microcrystallography and fully automated unassisted crystal screening and data collection to directly benefit our use community.