System Administrator

At the American College of Radiology (ACR), our work begins with a commitment to our members and the patients they serve. Representing nearly 40,000 radiologists, radiation oncologists, interventional radiologists, nuclear medicine physicians, and medical physicists, ACR is a recognized leader in patient-centered care, advocacy, quality, safety, education, policy, and clinical research. Every employee plays an important role in advancing ACR’s mission to serve patients and society by supporting our members, strengthening the profession, and helping shape the future of radiologic care.

With more than 500 employees across the United States, we are proud of our culture that is built on innovation, integrity, inclusion, and meaningful impact.

If you share our core values of:

* Integrity
* Visionary
* Excellence
* Leadership
* Transparency
* Member-Driven we need you on our team!

As a Systems Administrator
, you will work in a collaborative team environment to support the ACR IT infrastructure and staff. This critical role is responsible for building, configuring, patching, securing, and maintaining scalable, highly available infrastructure across physical servers, virtualized platforms, and cloud services. Key responsibilities include administering Windows and Linux servers; supporting AWS and hybrid-cloud resources; managing Microsoft 365, Active Directory, Entra , licensing, permissions, and access controls;

maintaining LAN/WAN connectivity and core services such as DNS, DHCP, TCP/IP, and Group Policy; supporting business applications, backups, disaster recovery, and security improvements; troubleshooting complex infrastructure issues; partnering with end users to implement technology solutions; and maintaining technical documentation and operational best practices. This position requires participation in scheduled monthly maintenance windows, typically occurring on Saturday nights, and in a rotating weekend on-call schedule.

• Deploy, configure, administer, and troubleshoot Windows and Linux servers across physical, virtual, and cloud environments to maintain performance, security, and availability.
• Monitor infrastructure health, capacity, availability, and performance; respond to alerts and proactively resolve issues before they affect business services.
• Administer and support AWS and hybrid-cloud infrastructure, including compute, storage, networking, security groups, identity and access management, and resource monitoring.
• Manage Microsoft 365, Active Directory, and Entra , including user and group administration, licensing, Group Policy, permissions, authentication, and access controls.
• Maintain core infrastructure and network services, including DNS, DHCP, TCP/IP, LAN/WAN connectivity, certificates, and related configuration standards.
• Install, configure, patch, upgrade, and troubleshoot operating systems, infrastructure tools, and business applications in accordance with change-management and security requirements.
• Support backup, restoration, disaster recovery, and business continuity processes; regularly verify job completion and recovery readiness.
• Implement security hardening, vulnerability remediation, privileged-access controls, and configuration improvements in partnership with information security teams.
• Serve as an escalation point for complex server, application, hardware, network, authentication, and connectivity incidents; perform root-cause analysis and document corrective actions.
• Automate routine administration, monitoring, reporting, and deployment tasks using appropriate scripting and configuration-management tools.
• Maintain accurate infrastructure inventories, system configurations, support records, diagrams, standard operating procedures, and disaster recovery documentation.
• Manage the lifecycle of infrastructure assets and services, including capacity planning, renewals, upgrades, vendor coordination, and retirement of obsolete systems.
• Partner with application, security, network, service desk, and business teams to plan and implement reliable technology solutions and production changes.
• Participate in scheduled maintenance windows and the on-call rotation, responding to critical incidents and supporting service restoration outside normal business hours.
• Research and recommend improvements that increase infrastructure reliability, security, scalability, automation, and operational efficiency.
• Perform other duties as assigned.

• Bachelor’s degree in computer science,…