In just a few months, on Friday morning, January 1, 2027, the new leader of the United Nations will take the express elevator to the 38th floor of the UN building in Turtle Bay to start their first day on the job. The race to determine who that person will be has generated months of debate and analysis. But there is another question few are asking: Who will accompany the next secretary-general in that elevator, and what will they do after they pass the heavy glass doors on the 38th floor?

As the organization looks to open a new chapter and recover from its current crisis, designing the best possible EOSG will be one of the new secretary-general-elect’s most consequential decisions and should be a top priority. This requires planning well before their official first day on the job. To reflect on the future of the EOSG, it is worth briefly reviewing its past and present.

The EOSG was established in 1946 to support the secretary-general in functions he retained personally rather than delegating to departments—including relations with member states, specialized agencies, and NGOs, policy coordination, and protocol. Its original structure was minimal: executive assistants, a General Assembly Section, and a Protocol and Liaison Section. Over eight decades, as the UN has grown, so has the EOSG, evolving into a complex structure of senior officials and thematic units at the center of the organization.

The backbone of the modern executive office is the chef de cabinet, a post that took its current title and rank of under-secretary-general in 1962. The chef de cabinet is the secretary-general’s chief of staff, responsible for managing the executive office, interfacing with member states, and supporting the secretary-general in the execution of his political role. They are a personal appointee of the secretary-general, and the role’s formal responsibilities have never been defined by an intergovernmental resolution.

In practice, the chef de cabinet has traditionally functioned as the chief executive of the organization on management matters, chairing the Management Committee, overseeing senior appointments, and the Standing Principals Group. A separate official typically runs the secretary-general’s front office and immediate schedule. António Guterres has appointed former permanent representatives for this position, including the current chef de cabinet, Courtenay Rattray. Because the role is defined by the secretary-general, its influence has depended less on the job title than on the personality of its holder and their relationship with the secretary-general.

A second key figure, the deputy secretary-general, is the most visible of the EOSG’s senior positions. Despite being codified by the General Assembly, it has historically been the least defined. The post was created in 1997 as part of Kofi Annan’s reform package. The officeholder is a personal appointee of the secretary-general following consultations with member states. While the General Assembly included a focus on institutional coherence and development when it established the role, ultimately it entails whatever the secretary-general chooses to delegate. This has varied considerably, sometimes even between a first and second mandate. Some deputy secretaries-general carried little institutional weight; others have shaped the organization in lasting ways.

Amina Mohammed, the fifth and current deputy secretary-general, chairs the UN Sustainable Development Group and oversees the Development Coordination Office, among other responsibilities. She is the first to serve two full terms. Crucially, these specific roles were not stipulated by any governing body resolution. It was a choice made by the secretary-general, and one the next secretary-general could reverse.

A third key figure in the EOSG is the person charged with overseeing system-wide policy coherence—translating the secretary-general’s priorities into institutional direction across the organization. This post, too, was established by Annan as part of his 1997 reforms at the level of assistant secretary-general, overseeing a small Strategic Planning Unit. The function continued into Ban’s tenure but lapsed in Ban’s second term and was not filled by the time the current secretary-general assumed office.

Guterres reestablished the post in his first term as the assistant secretary-general for strategic coordination. The person filling this role served as secretary of the Executive Committee and Senior Management Group and oversaw other strategic planning capacities. Guterres also appointed a senior adviser on policy at the level of under-secretary-general to oversee work on prevention, gender, and persons with disabilities. In his second term, he discontinued the latter post and elevated the former (then held by Volker Türk), with its existing terms of reference, to the rank of under-secretary-general, renaming the position as under-secretary-general for policy. This post is currently held by Guy Ryder, who in this capacity also oversees implementation of the Pact for the Future and the UN80 reform process.

The repeated reconfiguration of this strategic function across administrations—shifting in level, title, and mandate, lapsing and then renewed—reflects a longstanding tension in the EOSG over whether the secretary-general’s priorities should be driven from within the executive office or diffused across the system.

There are two possible approaches to managing the UN system through the EOSG. The first is direct management, which is largely the current configuration: an EOSG structured as an overarching center for coordination and guidance. The second is empowerment: an EOSG that sets the direction but delegates downward. This was reflected in the “lead department” approach taken by Annan and discontinued with the 2017 peace and security reforms. A return to the latter approach would require a fundamentally different—and leaner—EOSG architecture, with far-reaching implications for the system as a whole.

The personalities the secretary-general-elect brings into their inner circle will matter as much as the structure. Two profiles have historically predominated: former diplomats (particularly former permanent representatives, in recent years); and career UN insiders who have risen through the system. Occasionally, a third type has emerged from academia or civil society. Whether these individuals see their role as assertively shaping the organization’s direction or managing the expectations of member states will matter more than their titles.

The new secretary-general will be appointed in the fall of 2026. The transition period between their appointment and inauguration on January 1, 2027—a matter of months if not weeks—is when the architecture and personnel of the next EOSG will be decided. By the time the doors of the 38th floor close behind the new team on the first day of 2027, the most consequential decisions about the next secretary-general’s leadership will have already been made.