Senior Information Systems Security Officer (ISSO)

Senior Information Systems Security Officer (ISSO)

Location: Annapolis, MD / Reston, VA / Washington, DC Work Model: 100% Onsite (SCIF Environment) Work Type: Full-Time Experience Required: 13+ Years The Senior ISSO will support mission-critical cybersecurity initiatives within a highly secure government environment. This role involves risk management, compliance, ATO processes, and system security documentation, ensuring systems meet stringent federal and intelligence community security standards. This position requires deep expertise in RMF, XACTA, Splunk, and ICD 503 compliance frameworks, along with active TS/SCI clearance with CI Polygraph.

Key Responsibilities

Cybersecurity & Compliance

• Conduct technical security assessments and risk analysis • Ensure system compliance with RMF and ICD 503 frameworks • Support full lifecycle ATO/IATT processes

Documentation & RMF Activities

• Develop and maintain SSPs, POA&Ms, SAPs, and security artifacts • Use XACTA for documentation and compliance tracking • Coordinate with ISSMs, ISSEs, AOs, and system owners

ATO & Risk Management

• Drive ATO and IATT efforts across programs • Implement and validate NIST 800-53 security controls • Support audits and security assessment events

Technical & Operational Security

• Work with developers, DBAs, and system admins for compliance • Apply Zero Trust principles in cloud/data environments • Utilize Splunk for monitoring and analysis

Must-Have Qualifications

• Active TS/SCI clearance with CI Polygraph (Mandatory) • Security+ or IAT II/III Certification (Active) • 13+ years of experience in cybersecurity / systems engineering • Strong experience with RMF (Risk Management Framework) • Proficiency in XACTA and ATO/IATT processes • Experience with Splunk • Experience with ICD 503 / NIST 800-53 frameworks • Experience creating SSPs, POA&Ms, SAPs, and security documentation • Ability to work in SCIF (100% onsite)

Preferred Qualifications

• Prior ISSO or ISSE experience • Experience leading cybersecurity programs • Team leadership and mentoring experience • Strong stakeholder communication skills

Core Competencies

• Cybersecurity compliance & RMF • Risk management & ATO processes • Documentation & audit readiness • Technical security expertise • Communication & leadership

Work Environment

• Secure SCIF environment • Mission-critical government systems • Highly regulated cybersecurity setting