Accounting Co-Op

Flagship Pioneering invents and builds platform companies, each with the potential for multiple products that transform human health, sustainability and beyond. Since its launch in 2000, Flagship has originated more than 100 companies addressing some of the world’s most urgent challenges. Learn more at www.flagshippioneering.com.

At Flagship, we accept impossible missions to enable bigger leaps. Our core values guide us through uncertainty and toward lasting impact.

The Accounting Co-Op will support the day-to-day accounting and financial operations across a portfolio of emerging companies. This role provides hands-on experience in financial reporting, reconciliations, and month-end close processes in a fast-paced, innovative environment.

The Co-Op will work closely with the Accounting team and cross-functional partners, gaining exposure to real-world accounting systems, processes, and business operations while developing foundational technical and analytical skills.

- Assist with daily accounting operations, including expense report review, cash reconciliations, and basic reporting activities.

- Support the preparation and processing of cross-company invoices, ensuring accuracy and proper documentation.

- Help review lease invoices and assist with data entry and tracking within lease accounting systems (e.g., LeaseQuery).

- Participate in month-end, quarter-end, and year-end close processes, including assisting with journal entries and account reconciliations.

- Update financial tracking files and support data uploads, ensuring completeness and accuracy of financial data.

- Collaborate with teams such as FP&A, Accounts Payable, Procurement, and lab operations to support financial processes and business needs.

- Assist in maintaining and reconciling data across systems such as NetSuite, Expensify, and Coupa.

- Support audit preparation, documentation, and compliance-related activities as needed.

- Contribute to process improvement initiatives by identifying opportunities to enhance efficiency and accuracy.

- Assist with special projects and other ad hoc responsibilities as assigned.

- Gain hands-on experience with ERP systems (e.g., NetSuite) and accounting tools.

- Develop a strong understanding of the month-end close process and financial reporting.

- Build foundational knowledge of GAAP principles and internal controls.

- Strengthen analytical, organizational, and communication skills in a professional environment.

- Learn how accounting functions support high-growth, innovative companies.

- Currently pursuing a Bachelor’s degree in Accounting (required).

- Previous Co-Op or related internship experience in accounting or finance (required).

- Strong attention to detail and organizational skills.

- Basic knowledge of accounting principles.

- Proficiency in Microsoft Excel 

- Strong communication and teamwork skills.

- Duration: 6-month co-op 

- Location: Onsite  - Cambridge, MA offices

- Mentorship: Direct supervision and structured learning opportunities with the accounting team

The pay range for this role is $25 - $30 per hour. This role is a short-term engagement that is not eligible for health and welfare benefits. Retirement benefits may be available after completing a set number of hours. Compensation and benefits information is based on Flagship Pioneering's good faith estimate as of the date of publication and may be modified in the future.