Billing Specialist I

Amentum is seeking a Billing Specialist I to prepare detailed invoice packages with appropriate documentation and backup in accordance with standing policies and procedures. The role involves preparing and reconciling labor postings for Time & Materials (T&M) billing, preparing correcting journal entries for billing, and classifying billable versus non-billable costs based on program standards. The specialist will validate the accuracy of system transactions, research old transactions for billing purposes, perform detailed unbilled analysis, and conduct AR aging analysis. Additional responsibilities include maintaining accurate and complete records, tracking invoice status, following up with field and US-based teams on invoice and cost status, and timely reworking of invoice rejections. The role also requires responding to audit requests, verifying cost allocation, and receiving subcontracts’ invoices. The specialist will work collaboratively within a team of passionate professionals dedicated to making a meaningful impact in critical systems and programs of national importance across defense, security, intelligence, energy, and the environment.

Bachelor's Degree in Accounting, Finance, or Business; 3-5+ years of experience in an Accounting or Finance-related field; at least 2 years in an Accounting-specific function; strong English communication skills (written and oral); advanced math skills (University level); ability to define problems, collect and analyze data, establish facts, and propose solutions; ability to exercise sound judgment and make decisions independently; strong MS Office skills, especially in Excel and Word; strong analytical skills; highly detail-oriented; experience with Microsoft Dynamics and Cost Point is a plus.