Human Resources Business Partner

Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in more than 70 countries across all 7 continents. Amentum is seeking a Human Resources Business Partner to support the Modernization business line. The HRBP will provide timely, effective HR services and serve as a strategic partner to Program Managers and leadership within Mission Readiness & Modernization portfolio. This role is based in Sierra Vista, AZ to ensure consistent on‑site support. Essential Duties and Responsibilities: Partner with Program Managers and leaders to foster an inclusive, high‑performance culture and support workforce development. Implement HR policies and best practices, drive organizational change, and serve as an advocate for business needs. Collaborate with Talent Acquisition and Operations to assess staffing needs and ensure an efficient onboarding process. Advise managers and employees on performance management, employee relations, communications, training, and interpretation of employment laws and company policies. Provide on‑site guidance and recommend actions to strengthen employee engagement and address workforce concerns. Additional Responsibilities: Maintain a thorough understanding of employment laws to minimize risk and ensure compliance. Conduct stay and exit interviews and identify trends to support retention strategies. Assess training needs and deliver or coordinate non‑operational training. Lead group presentations on company policies, processes, and recurring programs such as orientation and benefits enrollment. Support program start‑up activities, including communications, briefings, onboarding, coordination with leadership and functional teams, and related system setup. Operate with minimal supervision and build strong relationships across all levels of the organization. Demonstrate effective communication, collaboration, facilitation, analytical ability, and sound judgment. Proactively research labor laws and regulations and recommend appropriate actions. Demonstrate adaptability, comfort with ambiguity, and the ability to lead and manage organizational change. Minimum Requirements: 5+years of hands‑on human resources experience. Experience providing HR leadership to a diverse workforce. Knowledge of HR disciplines, including recruiting, talent management, benefits, compensation, employee relations, training, and performance management. Strong knowledge of federal and state employment laws. Strong written communication, organizational skills, and attention to detail. Proficiency in Microsoft Office and ability to learn new systems quickly. Ability to obtain and maintain a Secret clearance (Note: U.S. Citizenship is required to obtain a clearance). Desired Qualifications: PHR or SHRM‑CP certification. Experience with Deltek Costpoint and Workday HRIS. Prior experience in government contracting. Active Secret clearance. Compensation & Benefits HIRING SALARY RANGE: $65K - $75K (Salary to be determined by the education, experience, knowledge, skills, and abilities of the applicant internal equity, and alignment with market data.) This position includes a competitive benefits package. For more detailed information on our Benefits and what it is like to work for Amentum: please visit our careers site: Compensation Details: $65,000 - $75,000 The compensation range or hourly rate listed for this position is provided as a good-faith estimate of what the company intends to offer for this role at the time this posting was issued. Actual compensation may vary based on factors such as job responsibilities, education, experience, skills, internal equity, market data, applicable collective bargaining agreements, and relevant laws. Benefits Overview: Our health and welfare benefits are designed to support you and your priorities. Offerings include: Health, dental, and vision insurance Paid time off and holidays Retirement benefits (including 401(k) matching) Educational reimbursement Parental leave Employee stock purchase plan Tax-saving options Disability and life insurance Pet insurance Note: Benefits may vary based on employment type, location, and applicable agreements. Positions governed by a Collective Bargaining Agreement (CBA), the McNamara-O'Hara Service Contract Act (SCA), or other employment contracts may include different provisions/benefits. Original Posting: 08/24/2026 - Until Filled Amentum anticipates this job requisition will remain open for at least three days, with a closing date no earlier than three days after the original posting. This timeline may change based on business needs. Amentum is proud to be an Equal Opportunity Employer. Our hiring practices provide equal opportunity for employment without regard to race, sex, sexual orientation, pregnancy (including pregnancy, childbirth, breastfeeding, or medical conditions related to pregnancy, childbirth, or breastfeeding), age, ancestry, United States military or veteran status, color, religion, creed, marital or domestic partner status, medical condition, genetic information, national origin, citizenship status, low-income status, or mental or physical disability so long as the essential functions of the job can be performed with or without reasonable accommodation, or any other protected category under federal, state, or local law. Learn more about your rights under Federal laws and supplemental language at Labor Laws Posters .