G&A Partners Executive and Leadership Team

May, 2026

Leadership Overview

G&A Partners has 6 executives leading key functions including strategy, operations, revenue, people, legal, and general counsel.

Driven by a commitment to empowering businesses, G&A Partners delivers comprehensive human resource solutions, encompassing HR management, payroll processing, and benefits administration to foster organizational success and streamline operations.

Leadership Roles at G&A Partners

  • Chief Executive Officer - Hyun Namgoong
  • Co-Founder & Chief Executive Officer - Antonio Grijalva
  • Chief Operating Officer - Aaron Call
  • Chief Revenue Officer - John Allen
  • Chief People Officer - Michelle Mikesell
  • Chief Legal Officer & General Counsel & Corporate Secretary - Stephen Calvert
  • Hyun Namgoong - Chief Executive Officer

    Hyun Namgoong, the Chief Executive Officer at G&A Partners, directs the overarching strategic vision and operational framework for the company's comprehensive human resource services. This leadership role involves guiding the organization's expansion and ensuring the delivery of integrated HR management, payroll processing, and benefits administration solutions. Namgoong focuses on optimizing service delivery models to enhance client satisfaction and drive sustainable growth across all business units. The executive's responsibilities include fostering innovation within service offerings and maintaining the company's competitive edge in the outsourcing market. By aligning departmental objectives with corporate goals, Hyun Namgoong ensures that G&A Partners consistently meets the evolving needs of its diverse client base, solidifying its position as a trusted partner in HR solutions.

    Antonio Grijalva - Co-Founder & Chief Executive Officer

    Antonio Grijalva, the Co-Founder & Chief Executive Officer at G&A Partners, spearheads the company's strategic direction and foundational principles, driving its mission to provide comprehensive human resource outsourcing. Grijalva's leadership encompasses the development and execution of business strategies that enhance HR management, payroll processing, and benefits administration services for clients. This executive role involves cultivating key partnerships and ensuring the company's service offerings remain at the forefront of industry innovation. By championing a client-centric approach, Antonio Grijalva ensures operational excellence and fosters a culture of continuous improvement. The executive's influence extends to shaping the company's long-term vision and market impact, reinforcing G&A Partners' commitment to empowering businesses through robust HR solutions.
    Antonio Grijalva

    Aaron Call - Chief Operating Officer

    Aaron Call, the Chief Operating Officer at G&A Partners, directs the operational efficiency and service delivery excellence across the organization's comprehensive human resource offerings. Call's responsibilities include optimizing the processes for HR management, payroll processing, and benefits administration, ensuring seamless execution for clients. This leadership position involves overseeing day-to-day operations, implementing best practices, and driving continuous improvement initiatives to enhance service quality and client satisfaction. Aaron Call focuses on streamlining workflows and managing resources effectively to support the company's growth objectives. The executive's strategic oversight ensures that G&A Partners maintains high standards of operational performance and reliability in delivering its outsourcing solutions.
    Aaron Call

    John Allen - Chief Revenue Officer

    John Allen, the Chief Revenue Officer at G&A Partners, architects the company's revenue generation strategies and oversees all sales and business development initiatives. Allen's purview includes expanding market reach for G&A Partners' comprehensive human resource services, encompassing HR management, payroll processing, and benefits administration. This critical role involves driving revenue growth through strategic client acquisition and retention programs across various market segments. By fostering strong relationships with prospective and existing clients, John Allen ensures the alignment of sales efforts with the company's overall business objectives. The executive's focus remains on optimizing the sales funnel and maximizing revenue streams to support the company's expansion and market leadership in HR outsourcing.
    John Allen

    Michelle Mikesell - Chief People Officer

    Michelle Mikesell, the Chief People Officer at G&A Partners, leads the strategic development and execution of all human capital initiatives, fostering a robust organizational culture. Mikesell's role encompasses talent acquisition, employee development, performance management, and ensuring a positive work environment that supports the company's comprehensive HR services. This executive position is vital for attracting and retaining top talent, which is essential for delivering exceptional HR management, payroll processing, and benefits administration to clients. Michelle Mikesell focuses on cultivating employee engagement and implementing programs that align with G&A Partners' mission and values. The executive's leadership ensures that the internal team is equipped and motivated to provide superior service and support to the company's client base.
    Stephen Calvert, the Chief Legal Officer & General Counsel & Corporate Secretary at G&A Partners, provides expert legal counsel and oversees all corporate governance matters. Calvert's extensive responsibilities include managing legal risks, ensuring regulatory compliance, and advising on all legal aspects of the company's comprehensive human resource services, including HR management, payroll processing, and benefits administration. This executive role is crucial for safeguarding the company's interests and maintaining its ethical and legal integrity. Stephen Calvert directs the legal strategy, supports contract negotiations, and oversees litigation, ensuring adherence to all applicable laws and regulations. The executive's guidance is instrumental in maintaining G&A Partners' reputation for trust and compliance in the outsourcing industry.
    Stephen Calvert

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    Frequently Asked Questions Regarding G&A Partners Top Executives and Leadership Team

    Who leads G&A Partners?
    G&A Partners is led by Hyun Namgoong (Chief Executive Officer), along with executives such as Antonio Grijalva (Co-Founder & Chief Executive Officer) and Aaron Call (Chief Operating Officer).
    Who is part of G&A Partners’s executive team?
    The executive team of G&A Partners includes leaders such as Hyun Namgoong (Chief Executive Officer), Antonio Grijalva (Co-Founder & Chief Executive Officer), Aaron Call (Chief Operating Officer) and other senior executives.
    How many executives does G&A Partners have?
    G&A Partners has 6 executives leading key business areas.
    What roles are included in G&A Partners’s leadership team?
    The leadership team of G&A Partners includes roles such as Chief Executive Officer, Co-Founder & Chief Executive Officer, Chief Operating Officer, Chief Revenue Officer, Chief People Officer.