System Administrator
Modern Government Solutions (MGS)
CLEARANCE REQUIRED: Active DoD TS/SCI with CI Polygraph EMPLOYMENT TYPE: Full-time, On-site POSITION SUMMARY Modern Government Solutions (MGS) is seeking a Systems Administrator (SA) to support the implementation, hardening, and maintenance of secure systems for mission-critical government programs. The SA will work alongside the program's ISSE and security team to implement technical controls, maintain system security posture, and support the ongoing fielding and maintenance of a Top Secret Contractor Wide Area Network (CWAN). The ideal candidate brings hands-on experience with system hardening, vulnerability management, and system administration in NRO-sponsored CWAN infrastructure, along with the ability to collaborate effectively across technical and program teams in classified environments. RESPONSIBILITIES (not limited to): Implement and maintain technical security controls across system architectures in coordination with the program's ISSE and security engineering team. Support the preparation and maintenance of security documentation, including contributions to System Security Plans (SSPs), Security Assessment Reports (SARs), POA&Ms, and related RMF artifacts as needed. Conduct hands‑on security assessments, vulnerability scans, and system hardening to identify and remediate potential weaknesses. Coordinate with the ISSE, developers, and network engineers to implement and maintain technical security controls and ensure ongoing compliance. Support security authorization and accreditation (A&A) processes to help achieve and maintain Authority to Operate (ATO). Participate in configuration management boards and change control processes as needed to support system administration activities. Collaborate with ISSOs, ISSMs, and government security officials to meet program security objectives and milestones. Stay current with evolving federal cybersecurity guidance, tools, and threat trends. REQUIRED SKILLS AND QUALIFICATIONS Must possess an active Department of Defense (DoD) TS/SCI with CI Polygraph security clearance. Bachelor's degree in Computer Science, Information Systems, Cybersecurity, Information Technology, or related field. 5+ years of experience in systems administration within a federal or DoD environment. Working familiarity with the Risk Management Framework (RMF) and associated documentation. Hands‑on experience with system hardening, vulnerability management, and security control implementation on Linux and/or Windows platforms. Working knowledge of NIST 800-53, CNSSI 1253, DoD 8510.01, and FISMA standards. Proficiency with common security tools such as ACAS, Nessus, STIG Viewer, or SCAP. Strong communication and documentation skills for preparing technical reports and security artifacts. Ability to collaborate across multidisciplinary technical teams and engage with government stakeholders. PREFERRED SKILLS AND QUALIFICATIONS Current Privileged User Access (PUA) on an active program or system. Direct experience implementing, administering, and/or maintaining NRO-sponsored CWAN infrastructure. Experience supporting RMF-based ATO processes for classified or cloud-based environments. Familiarity with Secure DevOps/DevSecOps pipelines and automation tools. Experience supporting DoD, IC, or other federal mission systems. *Applicants selected will be United States citizens and may be subject to a government security investigation for access to classified information.* ABOUT US At MGS, we believe a people-first culture corresponds to organizational success through a commitment to excellence, integrity, inclusion, and an attitude that welcomes challenges meets demands, sustains growth, and drives innovation. We provide expert mission‑first technical and programmatic services and solutions for the US intelligence community, the US Department of Defense, and other governmental agencies. We create people‑first organizational cultures where employees feel needed in the system, not a system that needs employees. We provide you with long‑term career opportunities centrally focused on our core value system: inclusion, integrity, and a commitment to excellence. MGS is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, or protected veteran status, and will not be discriminated against on the basis of disability. #J-18808-Ljbffr
$130k - $180k
Celestar, a B&A Company, is seeking a Database/Web System Administrator to support the Defense Advanced Research Projects Agency (DARPA) Program Security Services (PSS) task order. If interested and meet the qualifications, we encourage you to apply for this rewarding...SuggestedContract workLocal area$62k - $141k
Tier 2 System AdministratorThe Opportunity: Your combination of people skills and system administration knowledge makes you the team hero, solving one problem after another. What if you could use those skills to improve the technology supporting the DoD? Your blend of...SuggestedFull timeContract workPart timeWork at officeLocal areaRemote work- ...capabilities in AI/ML & Decision Analytics, Modeling and Simulation, and Future Force Assessments.SPA has a need for Systems & Infrastructure Administrators to operate, maintain, and improve the environments that host APACS and Foreign Clearance Program‑related...SuggestedFlexible hours
$104.2k - $138.9k
...a hybrid role working on-site 3 days/week in Arlington VA area. Candidates must have a current TS/SCI clearance.The Senior System Administrator leads the administration, maintenance, security, and operational resilience of complex enterprise infrastructure supporting...SuggestedRemote work3 days per week$62k - $141k
System Administrator, MidThe Opportunity: Your combination of people skills and system administrator expertise makes you the team hero, solving one problem after another. What if you could use those skills to improve the technology supporting our client?As a System Administrator...SuggestedFull timeContract workPart timeWork at officeLocal areaRemote work- DescriptionSr. Systems Administrator - Secret Xcelerate Solutions is seeking a Systems Administrator. Come join our award-winning organization and work with some of the most talented and brightest minds in the GovCon industry.Clearance: Secret Location: Remote Responsibilities...Remote work
$62k - $141k
...IT Systems AdministratorThe Opportunity:Are you looking for an opportunity to combine your technical skills with big picture thinking... ...a customer-focused engineering solution.As an IT Systems Administrator on our team, you'll have the chance to shape the development and...Full timeContract workPart timeWork at officeLocal areaRemote work- ...clearance with a Full Scope (FS) Polygraph. No exceptions. About System High System High Corporation delivers advanced protection... .... We are seeking an Information Technology (IT) Systems Administrator to join our team and support mission-critical programs through...Contract workImmediate start
- ...IT Systems Administrator As an IT Systems Administrator, you will be responsible for the administration, configuration and support of our systems, networks and software. Responsibilities Setting up and configuring new instances of Linux and Windows servers....Work at office
- ...The HPC group is looking for an experienced Linux systems administrator with HPC experience and programming skills, to join our team. The HPC team is responsible for purchasing, deploying, and maintaining HPC hardware and user tools for over 450 MITRE employees. The HPC...Work experience placement
- ...Senior Systems Administrator, Top Secret Security Clearance Required, Arlington, VAWe are seeking a Senior Systems Administrator to perform a wide variety of systems administration tasks. This could include installation, configuration, upgrades, and operational support...
- ...Senior Systems AdministratorGCI embodies excellence, integrity and professionalism. The employees supporting our customers deliver... ...industry.At GCI, we solve the hard problems. As a Senior Systems Administrator, a typical day will include the following duties:Position...Work at officeShift work
- ...Systems Planning and Analysis, Inc. (SPA) seeks Systems & Infrastructure Administrators to operate, maintain, and improve environments hosting APACS and related capabilities. The role focuses on availability, security, performance, and scalability across multiple environments...
$110k - $138k
...Overview The System Administrator provides system administration for all systems and applications supported by security guidance, orders and directives, identifying and remediating vulnerabilities, implementing and testing security controls, assisting with software...Temporary workImmediate startFlexible hoursShift work$64.1k - $102.9k
...regarding any recruiting communications or Kapitus' recruiting process in general should email ****@*****.*** As System Administrator I at Kapitus, you will be responsible for helping our company scale through the effective use of Microsoft 365 services....Temporary workWork experience placementRemote workFlexible hoursDay shift$106.3k - $221.1k
...System Administrator Arlington, VA At Accenture Federal Services, nothing matters more than helping the US federal government make the nation stronger and safer and life better for people. Our 13,000+ people are united in a shared purpose to pursue the limitless potential...Live inWork at officeLocal area- ...Systems AdministratorInnovative Defense Technologies (IDT), provider of cutting-edge cloud-based integration, automated testing and... ...systems in the US Department of Defense (DOD), is seeking a Systems Administrator to be part of our Security team and based out of our Arlington...Full timeWork at officeImmediate start
- ...System AdministratorMasonbyte is seeking to fill a System Administrator position for our customer in McLean, VA. At Masonbyte, we strive to provide the next generation of cutting-edge technologies. Our growth means exciting career opportunities for talented professionals...Permanent employment
- ...A government services contractor in Arlington, Virginia is seeking a Relativity Sr. Systems Administrator to facilitate government innovation through IT solutions. The ideal candidate will design and maintain systems using Relativity and AWS, alongside ensuring compliance...Full timeFor contractorsFlexible hours
- ...August 2025 Application Deadline: 29 August 2025 Department: Systems Engineering Location: Headquarters Description Aireon deployed... ...within the Aireon Network Engineering Group, the Senior Systems Administrator is responsible for helping to set up, maintain and manage...Permanent employmentFull timeTemporary workFor subcontractorWork at officeRemote workFlexible hours
$78.6k - $160.2k
...Senior Systems AdministratorAt Accenture Federal Services, nothing matters more than helping the US federal government make the nation... ...moves missions and the government forward!The Senior Systems Administrator oversees the management, security, and optimization of a mixed...Local area- ...Job Title Systems Administrator Location McLean, VA, 22101 Clearance TS/SCI Experience Level Mid Level Career (5+ yrs experience) Job Description The Systems Administrator will be responsible for maintaining and managing the company's computer...Flexible hours
$75k - $85k
...of Duty background investigation followed by DHS Public Trust Clearance Other (Travel, Work Environment, DoD 8570 Requirements, Administrative Notes, etc.) None $75,000 - $85,000 a year The offered rate will be based on the selected candidate’s knowledge, skills,...Local areaNight shiftWeekend work$60 - $65 per hour
...Immediate need for a talented System Administrator . This is a 06+ Months Contract opportunity with long-term potential and is located in Richmond, VA/McLean, VA (Hybrid) . Please review the job description below and contact me ASAP if you are interested. Job ID...Contract workLocal areaImmediate start$110k - $145k
...Systems AdministratorBoston, MAPlease Note: We have TWO openings for a Systems Administrator that can be based in one of our many office locations: Boston, MA - Charlotte, NC - Atlanta, GA - Asheville, NC - New York City, NY - Westwood, NJ - McLean, VAWhy Work At Modera...Work at officeLocal areaRemote workRelocation$75k - $113.79k
...Job Title: Systems Administrator III Clearance Required: Secret Work Location: Onsite, San Antonio, TX Key Responsibilities: Analyze, validate, implement, maintain, and configure current services and tools (examples include Active Directory (AD), System Center Operations...Contract workWork experience placementFlexible hours- ...Systems Administrator – Lead (LINUX)ASRC Federal Agile Decision Sciences LLC is seeking an experienced Systems Administrator – Lead (LINUX) to support the Command-and-Control Support Agency (CCSA), Technical Services Division (TSD) at the Pentagon. ASRC Federal performs...Full timeContract workFor subcontractorImmediate startRemote workMonday to Friday
- ...A federal IT solutions provider is seeking a Systems Administrator III to manage and support Active Directory and cloud services, ensuring security compliance and system optimization. The ideal candidate will have over 3 years of IT experience, a BS degree in a relevant...
- ...System AdministratorWe are seeking a proactive and detail-oriented System Administrator to join our team and help maintain the stability, security, and performance of our IT infrastructure. In this role, you will be responsible for managing servers, networks, and other...Temporary workImmediate start
$155k - $180k
...Senior System AdministratorAre you interested in using your skills to help shape the Cyber, Security, & Intel space? If so, look no further. Amentum is seeking a Senior System Administrator to join our team of passionate individuals in Springfield, VA. In this role you...Contract workLocal areaMonday to FridayShift work
Do you want to receive more vacancies?
Subscribe and receive similar vacancies to System Administrator. Be the first to apply!
- microsoft systems administrator McLean, VA
- remote systems administrator McLean, VA
- application system administrator McLean, VA
- IT administrator McLean, VA
- systems administrator McLean, VA
- computer systems administrator McLean, VA
- enterprise administrator McLean, VA
- system admin McLean, VA
- server administrator McLean, VA
- IT infrastructure administrator McLean, VA

