Senior Systems Administrator

General information

Requisition # R65299 Locations USA-IN-Crane Posting Date 01/16/2026 Security Clearance Required Interim Secret Remote Type Onsite Time Type Full time

Description & Requirements

Shape the future of defense with MANTECH! Join a team dedicated to safeguarding our nation through advanced tech and innovative solutions. Since 1968, we’ve been a trusted partner to the Department of Defense, delivering cutting-edge projects that make a real impact. Dive into exciting opportunities in Cybersecurity, IT, Data Analytics and more. Propel your career forward and be part of something extraordinary. Your journey starts now—protect and innovate with MANTECH!

MANTECH seeks a motivated, career and customer-oriented Senior Systems Administrator to join our team working in Crane, IN. This is a fulltime onsite position.

Responsibilities include but are not limited to:

• Design, implement, maintain, and support enterprise Microsoft Active Directory (AD) environments.

• Support enterprise network services by administering and optimizing GPO design, DNS, DHCP, and Windows Enterprise PKI

• Manage and support Public Key Infrastructure (PKI), including digital certificate issuance and validation across hybrid environments.

• Enhance and secure identity infrastructures through authentication, authorization, and access control policies.

• Troubleshoot and resolve issues related to domain services and directory integration.

• Collaborate with IT security and infrastructure teams to strengthen enterprise identity management and compliance.

• Apply understanding of authentication protocols such as Kerberos, LDAP, and SAML to enhance secure system access and identity management

• Operate in hybrid IT environments, integrating and supporting both on-premises infrastructure and cloud-based systems to meet mission and operational goals

Minimum Qualifications:

• High school diploma or equivalent

• 7+ years of systems administration or related experience

• Must have demonstrated experience in both active directory and PKI service administration

• Must possess one of the following certifications: CASP+, CISSP, or equivalent DoD 8570 baseline IAT 3 certification

Preferred Qualifications:

• Bachelor’s degree in an IT related field

• Microsoft Certified: Identity and Access Administrator Associate, or equivalent.

• Demonstrated expertise in Active Directory architecture and administration.

Clearance Requirements:

• Must be a U.S. Citizen and have the ability to obtain and maintain a Secret security clearance.

• Candidate will be required to obtain an interim Secret clearance before onboarding 

Physical Requirements:

• The person in this position must be able to remain in a stationary position 80% of the time.