HSS Executive and Leadership Team

July, 2026

Leadership Overview

HSS has 10 executives leading key functions including strategy, finance, operations, medical affairs, and information technology.

Driven by a legacy of medical advancement, HSS is dedicated to transforming musculoskeletal care through world-class education, research, and patient treatment, solidifying its position as a global leader in orthopedic medicine.

Leadership Roles at HSS

  • Chief Executive Officer - KiHyung Kim
  • Executive Administrator & Office of The President & Chief Executive Officer - Lisa Valerioti
  • Chief of Staff To the President and Chief Executive Officer - Noareen Ahmed
  • Chief Financial Officer - Daniel Montgomery
  • Chief Operating Officer - Caloy Penz
  • Chief Operating Officer & Executive Vice President - Mary Cassai
  • Chief Operating Officer & Executive Vice President - Mary Cassai Nea-Bc Mpa
  • Chief of Staff & Office of The Chief Data & Analytics Officer - Mary Mcmahon
  • Vice President & Chief Information Officer - John Cox
  • Chief Medical Officer - Sheeraz Qureshi
  • KiHyung Kim - Chief Executive Officer

    KiHyung Kim, the Chief Executive Officer at HSS, directs the overarching strategy and operational execution for the world's preeminent musculoskeletal hospital. This leadership role involves guiding HSS's transformation from its historical roots into a modern academic medical center, ensuring continued excellence in education, research, and patient care. Kim's focus centers on advancing the hospital's mission to train leading orthopedic surgeons and maintain its global leadership in musculoskeletal health. The Chief Executive Officer's responsibilities encompass fostering innovation across all departments, from clinical services to groundbreaking research initiatives. This executive drives the vision for HSS, ensuring alignment with its founding principles of educational rigor and patient-centered outcomes. KiHyung Kim's strategic direction shapes the future of orthopedic medicine, impacting patient care and medical training worldwide.

    Lisa Valerioti - Executive Administrator & Office of The President & Chief Executive Officer

    Lisa Valerioti, the Executive Administrator & Office of The President & Chief Executive Officer at HSS, provides critical administrative support and operational management for the hospital's highest leadership positions. This role ensures the seamless functioning of the President and Chief Executive Officer's office, facilitating strategic initiatives and daily operations. Valerioti manages complex scheduling, coordinates executive communications, and supports the implementation of key organizational projects. The Executive Administrator's responsibilities extend to overseeing administrative staff and optimizing office workflows to enhance executive efficiency. This position is vital for maintaining the operational integrity of the leadership team, enabling them to focus on HSS's mission of advancing musculoskeletal care. Lisa Valerioti's dedicated support underpins the hospital's commitment to excellence in patient treatment and medical education.
    Lisa Valerioti

    Noareen Ahmed - Chief of Staff To the President and Chief Executive Officer

    Noareen Ahmed, the Chief of Staff To the President and Chief Executive Officer at HSS, provides essential strategic and operational support to the hospital's top leadership. This role ensures the effective execution of the President and CEO's agenda, managing key initiatives and facilitating communication across the organization. Ahmed coordinates critical projects, oversees executive communications, and supports the strategic direction of HSS, reinforcing its commitment to advancing musculoskeletal care. The Chief of Staff's responsibilities include streamlining executive operations, managing priorities, and ensuring alignment with the hospital's mission of excellence in education, research, and patient treatment. This position is vital for the efficient functioning of the executive office, enabling leadership to focus on HSS's role as a preeminent academic medical center. Noareen Ahmed's contributions are instrumental in driving HSS's continued success and leadership in orthopedic medicine.

    Daniel Montgomery - Chief Financial Officer

    Daniel Montgomery, the Chief Financial Officer at HSS, oversees all financial operations, strategic financial planning, and fiscal management for the institution. This leadership position is responsible for ensuring the financial health and sustainability of HSS, a globally recognized musculoskeletal hospital. Montgomery directs budgeting, forecasting, investment strategies, and financial reporting, aligning fiscal policies with the hospital's mission of excellence in education, research, and patient care. The Chief Financial Officer's role involves managing financial risks, optimizing resource allocation, and driving revenue growth through strategic initiatives. This executive collaborates closely with other C-suite leaders to support HSS's expansion and innovation efforts. Daniel Montgomery's financial acumen is crucial for maintaining HSS's status as a preeminent academic medical center and for funding its ongoing contributions to orthopedic medicine.

    Caloy Penz - Chief Operating Officer

    Caloy Penz, the Chief Operating Officer at HSS, directs the day-to-day operational activities and service delivery across the hospital's extensive network. This executive is responsible for optimizing operational efficiency, enhancing patient throughput, and ensuring the highest standards of care are consistently met. Penz oversees various departments, focusing on streamlining processes, managing resources effectively, and implementing best practices in healthcare operations. The Chief Operating Officer's role involves driving operational excellence to support HSS's mission as the world's leading musculoskeletal hospital. This leadership position is critical for managing the complex logistical demands of a major academic medical center, ensuring seamless patient experiences and supporting research and educational endeavors. Caloy Penz's operational leadership ensures HSS maintains its commitment to advancing orthopedic medicine and patient outcomes.

    Mary Cassai - Chief Operating Officer & Executive Vice President

    Mary Cassai, the Chief Operating Officer & Executive Vice President at HSS, drives operational strategy and execution across multiple facets of the hospital's extensive healthcare services. This dual role encompasses overseeing critical operational functions and contributing to the executive leadership's strategic vision for HSS. Cassai focuses on enhancing patient care delivery, optimizing resource utilization, and ensuring the highest standards of operational efficiency align with the hospital's mission as a world leader in musculoskeletal health. The Chief Operating Officer & Executive Vice President's responsibilities include managing complex projects, fostering interdepartmental collaboration, and implementing innovative operational models. This executive's leadership is essential for maintaining HSS's reputation for excellence in patient treatment, research, and education. Mary Cassai's strategic oversight ensures HSS continues its legacy of advancing orthopedic medicine.
    Mary Cassai

    Mary Cassai Nea-Bc Mpa - Chief Operating Officer & Executive Vice President

    Mary Cassai Nea-Bc Mpa, the Chief Operating Officer & Executive Vice President at HSS, leads critical operational functions and contributes significantly to the hospital's executive strategy. This role involves overseeing complex operational frameworks and driving initiatives that enhance patient care delivery and institutional efficiency. Cassai focuses on optimizing resource allocation and implementing best practices to uphold HSS's standing as a premier academic medical center for musculoskeletal health. The Chief Operating Officer & Executive Vice President's responsibilities include managing large-scale projects, fostering collaboration among diverse departments, and advancing the hospital's operational capabilities. This executive's leadership is fundamental to maintaining HSS's reputation for excellence in treatment, research, and medical training. Mary Cassai Nea-Bc Mpa's strategic operational guidance supports HSS's ongoing advancements in orthopedic medicine.

    Mary Mcmahon - Chief of Staff & Office of The Chief Data & Analytics Officer

    Mary Mcmahon, the Chief of Staff & Office of The Chief Data & Analytics Officer at HSS, provides strategic support and operational coordination for data-driven initiatives and executive leadership. This role bridges executive strategy with the implementation of advanced analytics and data management across the hospital. Mcmahon facilitates the execution of data strategies, ensuring alignment with HSS's mission to lead in musculoskeletal care through innovation and research. The Chief of Staff's responsibilities include managing key projects, coordinating cross-departmental efforts, and supporting the Chief Data & Analytics Officer in leveraging data for improved patient outcomes and operational efficiency. This position is integral to advancing HSS's capabilities in data science and analytics, reinforcing its status as a preeminent academic medical center. Mary Mcmahon's efforts enhance HSS's ability to utilize data for medical advancement and operational excellence.

    John Cox - Vice President & Chief Information Officer

    John Cox, the Vice President & Chief Information Officer at HSS, directs the hospital's information technology strategy, infrastructure, and digital transformation efforts. This executive is responsible for ensuring robust, secure, and innovative technology solutions that support HSS's mission in patient care, research, and education. Cox oversees all aspects of IT operations, including data management, cybersecurity, electronic health records, and the implementation of new digital tools. The Vice President & Chief Information Officer's role is critical in leveraging technology to enhance operational efficiency and patient outcomes at the world's leading musculoskeletal hospital. This leadership position drives the integration of advanced technologies to support HSS's commitment to medical excellence and innovation. John Cox's strategic technology leadership ensures HSS remains at the forefront of healthcare innovation and patient service.

    Sheeraz Qureshi - Chief Medical Officer

    Sheeraz Qureshi, the Chief Medical Officer at HSS, directs the clinical strategy and medical affairs for the institution, ensuring the highest standards of patient care and clinical excellence. This executive leads the medical staff, oversees clinical quality initiatives, and guides the integration of research findings into patient treatment protocols. Qureshi is responsible for advancing HSS's mission as the preeminent musculoskeletal hospital by fostering a culture of clinical innovation and patient-centered care. The Chief Medical Officer's role involves collaborating with operational leaders to optimize clinical workflows and enhance patient outcomes across all service lines. This leadership position is vital for maintaining HSS's global reputation in orthopedic medicine and for shaping the future of musculoskeletal healthcare. Sheeraz Qureshi's medical leadership ensures HSS continues to set benchmarks in patient safety and clinical effectiveness.
    Sheeraz Qureshi

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    Frequently Asked Questions Regarding HSS Top Executives and Leadership Team

    Who leads HSS?
    HSS is led by KiHyung Kim (Chief Executive Officer), along with executives such as Lisa Valerioti (Executive Administrator & Office of The President & Chief Executive Officer) and Noareen Ahmed (Chief of Staff To the President and Chief Executive Officer).
    Who is part of HSS’s executive team?
    The executive team of HSS includes leaders such as KiHyung Kim (Chief Executive Officer), Lisa Valerioti (Executive Administrator & Office of The President & Chief Executive Officer), Noareen Ahmed (Chief of Staff To the President and Chief Executive Officer) and other senior executives.
    How many executives does HSS have?
    HSS has 10 executives leading key business areas.
    What roles are included in HSS’s leadership team?
    The leadership team of HSS includes roles such as Chief Executive Officer, Executive Administrator & Office of The President & Chief Executive Officer, Chief of Staff To the President and Chief Executive Officer, Chief Financial Officer, Chief Operating Officer.