Systems Administrator (SA) - TS/SCI with CI Polygraph

Modern Government Solutions; McLean (VA); On-site; USD 110,000 - 150,000; Full time

Job summary

Modern Government Solutions (MGS) is seeking a Systems Administrator to support secure government CWAN infrastructure in McLean, VA. The SA will work with the ISSE and security team to implement controls and maintain system security posture.

The ideal candidate brings hands-on experience with system hardening, vulnerability management, and RMF-based security in a DoD environment, collaborating across technical teams in classified settings.

Qualifications

• Active DoD TS/SCI with CI Polygraph clearance required.
• 5+ years of systems administration in federal/DoD environments.
• Working familiarity with RMF and related documentation.
• Hands-on system hardening, vulnerability management on Linux/Windows.
• Familiarity with NIST 800-53, CNSSI 1253, DoD 8510.01, and FISMA.
• Proficient with security tools ACAS, Nessus, STIG Viewer, SCAP.
• Strong written and verbal communication for technical reports.

Responsibilities

• Implement and maintain technical security controls with ISSE and security team.
• Prepare and maintain security docs: SSPs, SARs, POA&Ms, RMF artifacts.
• Conduct security assessments, vulnerability scans, and hardening.
• Coordinate with ISSE, developers, and network engineers for controls.
• Support A&A processes to achieve Authority to Operate (ATO).
• Participate in configuration management boards and change control.
• Collaborate with ISSOs/ISSMs and government security officials.
• Stay current with evolving federal cybersecurity guidance and threats.

Skills

System hardening

Vulnerability management

RMF familiarity

Security controls implementation

Communication skills

Education

Bachelor's degree in Computer Science / Information Systems / Cybersecurity / IT

Tools

ACAS

Nessus

STIG Viewer

SCAP

Job description

TITLE: Systems Administrator (SA)

LOCATION: McLean, VA

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.
• DoD 8570 IAT Level II/III certification (e.g., Security+, CISSP, CISM, CASP).
• 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.