Title: Blanket annual preventative maintenance/repair coverage for listed microscopes manufactured by Carl Zeiss Microscopy and operated by the National Eye Institute. Background Information: The National Eye Institute-NIH conducts basic, clinical, and translational research to identify the cellular and molecular basis of mechanisms leading to inherited and acquired eye diseases and develops therapies for treating these blinding disorders to preserve or restore vision in patients. To carry out this mission, the scientist and clinicians conducting research at the NEI require access to microscopes and imaging systems that are regularly serviced and repaired and are fully functional. These microscopes and imaging systems are among the most complicated and heavily used instruments by research scientists at the National Eye Institute- NIH Bethesda. Many of these systems rely on proprietary technology and specialized components to operate appropriately. Factory-trained service engineers with the expertise and knowledge of these technologies and access to specialized diagnostic tools (service dongles, etc.)are required to properly diagnose malfunctions when they occur. The original equipment manufacturer is often the only source of replacement parts for these complex instruments. In addition to onsite maintenance and repair of microscopes, Zeiss maintenance agreements include responsive customer service consultation and troubleshooting by phone, email and remote diagnostics. These services improve diagnosis and remediation of service issue and reduce “downtime” for users. The National Eye Institute currently operates 39 microscopes manufactured by Carl Zeiss Microscopy LLC (White Plains, NY). These instruments are critical to NEI research efforts and require annual maintenance evaluations to ensure that these systems are functioning properly. If malfunctions or deficiencies are observed, Zeiss service engineers will attempt to repair the malfunction based on repair parts' availability. Some of these systems were previously covered by annual service agreements obtained through third parties rather than Carl Zeiss Microscopy LLC. Some of them never had any coverage. Repair services delivered by these third-party entities were unacceptable for the following reasons: 1) the third-party service failed to deliver timely repair and return to service for these critical microscope systems. These deficiencies resulted in reduced instrument performance and diminished scientific productivity.