Senior ISSO

Apex Systems; Oxon Hill (MD); On-site; USD 117,000 - 124,000; Full time

Job summary

Everforth Apex is seeking a Senior Information System Security Officer (ISSO) to lead RMF lifecycle activities and ATO efforts for federal systems in a national Harbor/On-site setting.

You will coordinate with government counterparts, develop and maintain security documentation, and ensure compliance with FISMA, DHS 4300 Series, and NIST standards while supporting audits and assessments.

Qualifications

• Bachelor’s degree required; 6+ years of relevant work experience. Master’s preferred.
• Proven IT security management and compliance experience with FISMA, DHS 4300 Series, and NIST directives.

Responsibilities

• Serve as the subject-matter expert for federal agency counterparts on security compliance and documentation.
• Lead ATO efforts and RMF processes, ensuring compliance with standards.
• Prepare, update, and review security artifacts and RMF/ATO packages.

Skills

FISMA

RMF

NIST

SecurityAudits

ATO

Education

Bachelor's degree

Master's degree preferred

Tools

MS Word

MS Excel

MS PowerPoint

MS Project

Job description

# Senior ISSOApply**Job#: 3055833****Job Description:** *Candidates must be U.S. citizens able to obtain and/or maintain a Department of Defense security clearance as a condition and continuation of employment.*Senior ISSO**Location:** National Harbor, MD (On-site)Role OverviewWe are recruiting a Senior Information System Security Officer (ISSO) to serve as a subject-matter expert supporting federal security compliance. This pivotal role ensures the security and compliance of customer systems throughout the Risk Management Framework (RMF) lifecycle. The Senior ISSO will be the primary point of contact for government counterparts, supporting security compliance, documentation, and proactive preparation of submissions in alignment with federal security standards.Key Responsibilities* Serve as the subject-matter expert and primary point of contact for federal agency counterparts, supporting security compliance and documentation.* Lead systems' Authority to Operate (ATO) efforts and maintain compliance with FISMA, DHS 4300 Series, and NIST standards.* Create, update, and assess the readiness of system Authority to Operate (ATO) packages.* Develop, update, and review required security artifacts and ensure all system security documentation is current.* Translate technical requirements effectively between security stakeholders and technical architects.* Conduct IT security assessments and support IT security audits to ensure compliance.* Maintain Plan of Action & Milestone (POA&M) reports, ensuring security vulnerabilities are tracked and reported.* Provide information security expertise to system development teams throughout the System Engineering Lifecycle.Required Qualifications**Education:**A Bachelor’s degree with 6+ years of relevant work experience is required. A Master’s degree is preferred. Extensive, direct experience may be considered in lieu of a degree.**Experience:*** Proven experience in IT security management and compliance, specifically with FISMA, DHS 4300 Series, and NIST directives.* Direct experience leading Authority to Operate (ATO) and Risk Management Framework (RMF) processes is strongly preferred.* Experience focused on compliance and security documentation is critical.* Must be a U.S. Citizen.**Technical Skills:*** In-depth knowledge of FISMA, DHS 4300, and FIPS requirements.* Ability to conduct security assessments and audits.* Proficiency in Microsoft applications (MS Word, Excel, PowerPoint, Project).* Strong analytical and problem-solving skills.Preferred Qualifications* Experience supporting federal projects, particularly for DoD or FEMA.* Experience managing matrix teams in a fast-paced, mission-critical environment. *Everforth Apex is a world-class IT services company that serves thousands of clients across the globe. When you join Everforth Apex, you become part of a team that values innovation, collaboration, and continuous learning. We offer quality career resources, training, certifications, development opportunities, and a comprehensive benefits package. Our commitment to excellence is reflected in many awards, including ClearlyRateds Best of Staffing in Talent Satisfaction in the United States and Great Place to Work in the United Kingdom and Mexico.**Everforth Apex uses a virtual recruiter as part of the application process. Click here for more details. By applying for this job, you agree to receive calls, AI-generated calls, text messages, or emails from Everforth Apex and its affiliates, and contracted partners. Frequency varies for text messages. Message and data rates may apply. Carriers are not liable for delayed or undelivered messages. You can reply STOP to cancel and HELP for help. You can access our privacy policy at https://www.apexsystems.com/privacy-policy**Everforth Apex Benefits Overview: Everforth Apex offers a range of supplemental benefits, including medical, dental, vision, life, disability, and other insurance plans that offer an optional layer of financial protection. We offer an ESPP (employee stock purchase program) and a 401K program which allows you to contribute typically within 30 days of starting, with a company match after 12 months of tenure. Everforth Apex also offers a HSA (Health Savings Account on the HDHP plan), a SupportLinc Employee Assistance Program (EAP) with up to 8 free counseling sessions, a corporate discount savings program and other discounts. In terms of professional development, Everforth Apex hosts an on-demand training program, provides access to certification prep and a library of technical and leadership courses/books/seminars once you have 6+ months of tenure, and certification discounts and other perks to associations that include CompTIA and IIBA. Everforth Apex has a dedicated customer service team for our Consultants that can address questions around benefits and other resources, as well as a certified Career Coach. You can access a full list of our benefits, programs, support teams and resources within our ‘Welcome Packet’ as well, which an Everforth Apex team member can provide.**Everforth Apex Systems is an equal opportunity employer. We do not discriminate or allow discrimination on the basis of race, color, religion, creed, sex (including pregnancy, childbirth, breastfeeding, or related medical conditions), age, sexual orientation, gender identity, national origin, ancestry, citizenship, genetic information, registered domestic partner status, marital status, disability, status as a crime victim, protected veteran status, political affiliation, union membership, or any other characteristic protected by law. Everforth Apex will consider qualified applicants with criminal histories in a manner consistent with the requirements of applicable law.**If you require an accommodation under the Americans with Disabilities Act to participate in an interview with a virtual recruiter or to use our website for a search or application, please contact our Benefits Department at [e-mail] or 804-523-8228. Please note that this contact information is strictly to be used for medical ADA accommodations and that no other inquiries will be answered.**UnitedHealthcare creates and publishes the Transparency in Coverage Machine-Readable Files on behalf of Everforth Apex Systems.***Employee Type:** Contract**Location:** Oxon Hill, MD, US**Job Type:****Date Posted:** October 14, 2026**Pay Range:** $85 - $90 per hour