World Health Organization: Membership, Organs, and Core Functions

The World Health Organization (WHO) is the United Nations system’s specialized agency for international health cooperation. Its legal identity comes from the WHO Constitution, which was adopted in 1946 and entered into force on 7 April 1948. The 7 April anniversary is also observed as World Health Day.

The Constitution establishes the WHO as a specialized agency under Article 57 of the United Nations Charter. The Organization is headquartered in Geneva, Switzerland.

The Constitution gives the WHO the objective of “the attainment by all peoples of the highest possible level of health.” It defines health in positive terms: physical, mental, and social well-being. The definition is broader than the absence of disease or infirmity. That constitutional health mandate does not make the Organization a government above governments.

The WHO works as an institutional hub of the international health regime. Its work moves through three main channels: convening governments, producing technical standards, and supporting national health authorities. The Organization also gathers health information and coordinates emergency responses. WHO authority depends first on consent from governments and on technical credibility. Formal legal instruments and national implementation turn that authority into practice.

Membership and voting

The Organization has 194 Member States in its public country listing. Membership is open to all states. Members of the United Nations may join by accepting the Constitution. Other states may be admitted by a simple majority vote of the World Health Assembly. The Constitution also provides for Associate Members, a category for territories that are not responsible for their own international relations. In those cases, the application is made by the responsible Member or authority.

Member States are grouped into six regions. Each Member has one vote in the World Health Assembly. Important questions require a two-thirds majority of Members present and voting. Other questions require a simple majority of those present and voting. This voting rule gives the Assembly a formally intergovernmental character: states are the basic units of constitutional decision-making, even when the subject is technical health policy.

Membership figures can become politically sensitive when a state gives notice of withdrawal or when the legal status of a state or territory is disputed. The current country listing includes a note on a United States withdrawal notification circulated by the United Nations Secretary-General in 2025. The notification gave 22 January 2026 as the stated effective date, while it remained pending consideration by WHO governing bodies. Membership counts should therefore be read together with any official dated footnote.

Constitutional organs

The WHO Constitution identifies its three principal organs:

• the World Health Assembly;
• the Executive Board;
• and the Secretariat.

The WHO Constitution gives formal authority to these three organs. Meanwhile, other WHO structures have supporting or specialized roles. Regional offices adapt the Organization’s work to local conditions, while emergency committees advise during specific health events. In addition, special programs and advisory networks support defined parts of WHO’s technical work.

The Assembly is the supreme decision-making body. The Executive Board gives effect to Assembly decisions and performs advisory work before matters reach the Assembly. The Secretariat, led by the Director-General, carries out technical and administrative work.

This structure explains why the WHO is both technical and political. Its staff produce expert guidance and coordinate programs, whereas governments set the mandate and budget through the formal organs. They also choose the leadership and decide which legal instruments the Organization adopts. The WHO’s institutional design therefore combines public-health expertise with intergovernmental control.

The World Health Assembly

The World Health Assembly is the WHO’s supreme decision-making body. Delegations from all Member States attend it, and it normally meets annually in Geneva. The Assembly determines WHO policies and appoints the Director-General. It supervises financial policy, approves the program budget, reviews Executive Board reports, and names the Members entitled to designate persons to serve on the Board.

The Assembly also has lawmaking and standard-setting functions within the constitutional framework of the Organization. The Assembly can adopt conventions or agreements on matters within WHO competence. It can also adopt regulations in specified fields and make recommendations to Members. Those powers make the Assembly more than an advisory forum, even though implementation of its decisions still runs mainly through states.

The Assembly’s intergovernmental character shapes the pace and content of WHO actions. For instance, a health emergency may create scientific urgency, but governments still negotiate issues regarding authority and funding before collective action can proceed. The Assembly, therefore, is the forum where public-health evidence becomes institutional action through diplomacy.

The Executive Board

The Executive Board is the WHO organ that turns Assembly decisions into continuing governance. It has 34 technically qualified members. The World Health Assembly elects the Member States entitled to designate those persons. Each term lasts three years. To keep that technical body geographically balanced, the Constitution requires equitable distribution, with at least three members from each WHO region. In ordinary years, the Board holds a main meeting in January and a shorter meeting after the Health Assembly, usually in May or June.

The Board’s central function is to give effect to Health Assembly decisions and policies. In that role, it advises the Assembly, prepares its agenda, and studies assigned matters. When urgency requires faster action, it can also take emergency measures within WHO’s functions and financial resources. The Board therefore links annual intergovernmental decisions with WHO’s continuous technical and administrative work.

The phrase “technically qualified” signals that WHO governance should be informed by public-health competence as well as diplomatic representation. At the same time, Board members are still designated by elected Member States, so the Board remains embedded in intergovernmental politics. Its practical influence often lies in agenda-setting before issues reach the full Assembly. The Board also reviews how Assembly decisions are being implemented.

The Secretariat and Director-General

The Secretariat consists of the Director-General and the technical and administrative staff of the Organization. The World Health Assembly appoints the Director-General on the nomination of the Executive Board. The Director-General is the WHO’s chief technical and administrative officer, responsible for leading the Secretariat and implementing the work authorized by Member States.

The Constitution protects the international character of the Secretariat. In accordance with that rule, the Director-General and staff must not seek or receive instructions from governments or external authorities. At the same time, Member States must respect the international nature of those responsibilities. This independence rule supports WHO’s credibility as a technical institution. Staff must be able to assess health risks and publish guidance on professional grounds.

Dr. Tedros Adhanom Ghebreyesus was elected Director-General in 2017 and re-elected in 2022. His second term began on 16 August 2022, and the next Director-General election is expected in 2027. Beyond the Director-General, the Secretariat includes more than 8,000 professionals across headquarters and field offices. Those professionals give WHO technical reach. However, their work remains bounded by mandates, budgets, and cooperation from national authorities.

Regions, offices, and field work

WHO has six regional organizations, one for each of its regions: Africa, the Americas, South-East Asia, Europe, the Eastern Mediterranean, and the Western Pacific. Each regional organization has a regional committee and a regional office. The Constitution treats those regional organizations as integral parts of WHO.

Regional committees adapt WHO work to regional conditions. More specifically, they formulate policy for their regions and supervise regional offices. They can also recommend additional work or advise the Organization on regional health matters.

Regional offices are the administrative organs of regional committees. They carry out decisions of the World Health Assembly and Executive Board in their regions. Because implementation differs across health systems, their work must fit local health conditions and institutional capacity. This regional structure gives WHO a decentralized form. Global standards are supported through regional priorities and regional administration.

The Organization’s field structure extends beyond the six regional offices. It includes a network of country offices and other offices, and WHO is present in more than 150 countries. In those settings, country offices collaborate with national governments and partners. Their everyday work links health ministries with planning support, program monitoring, and assistance to local health systems. Country offices turn much of WHO’s global authority into practical cooperation with ministries and emergency teams.

The regional and country-office structure is especially important in emergencies and long-term system strengthening. Geneva may coordinate global policy, but surveillance capacity and emergency logistics often depend on country-level relationships. For that reason, WHO’s institutional design combines central standard-setting with field-based cooperation.

What the WHO does

Under the WHO Constitution, the Organization is the directing and coordinating authority on international health work. In practice, that function has four main dimensions: coordination, government support, technical standard-setting, and emergency response.

First, WHO acts as a convener and coordinator. It brings governments into the same process as UN bodies, scientific networks, and professional groups. This matters, for instance, because infectious diseases and emergency supply chains often cross borders faster than domestic institutions can act alone.

Second, WHO supports governments and health systems. Its Constitution authorizes it to provide assistance to governments, on request, in strengthening health services. It also authorizes emergency aid when governments request or accept it. Nevertheless, WHO assistance usually depends on state consent and national implementation, even when a public-health problem has international effects.

Third, WHO works on surveillance, data, and disease control. For that purpose, the Constitution authorizes the Organization to maintain epidemiological and statistical services. WHO can also support disease-eradication work and standardize diagnostic procedures. Together, those functions help national systems compare health information through a shared technical vocabulary.

Fourth, WHO promotes standards, research, and professional cooperation. Its influence often comes through usable reference points. Guidance documents tell health authorities how to act. Classifications and surveillance rules make national data comparable. Product standards, in turn, help align regulation. Together, these tools let separate national systems work from comparable assumptions during ordinary programs and emergencies.

Legal instruments and emergency rules

The WHO Constitution gives the World Health Assembly several legal and normative tools. The main tools in this context are:

• Article 19, which allows the Assembly to adopt conventions or agreements on matters within WHO competence, requiring a two-thirds Assembly vote;
• Article 21, which allows the Assembly to adopt regulations in specified technical fields, including sanitary requirements, disease nomenclatures, diagnostic procedures, product standards, and labeling rules;
• and Article 23, which gives the Assembly a softer instrument: recommendations to Members.

Article 22 gives regulations adopted under Article 21 a distinctive legal effect. Those regulations come into force for Members after due notice, except for Members that notify rejection or reservations within the stated period. Article 21 is therefore one of the WHO system’s strongest formal tools, but legal force still depends on state implementation.

The International Health Regulations are the main contemporary example of WHO emergency-related law. They are a legally binding framework for managing public-health risks that may cross borders. Currently, the IHR have 196 States Parties, including all WHO Member States.

The IHR require States Parties to designate authorities and maintain core capacities. They also require notification of events that may constitute a public health emergency of international concern. When WHO requests verification, States Parties must respond through the IHR process. In this way, the IHR turn emergency cooperation into a sequence of duties, assessments, and communications.

Under the IHR framework, WHO performs early warning and event assessment. The Organization also coordinates parts of the international public-health response. It gives technical support, monitors implementation, and determines whether an event constitutes a public health emergency of international concern.

The amended IHR text that entered into force on 19 September 2025 incorporates amendments adopted in 2014, 2022, and 2024. However, the 2024 amendments did not apply uniformly to every State Party at entry into force, because WHO reported that 11 of the 196 States Parties had rejected them. The IHR therefore make procedure the main channel of WHO emergency authority, while still leaving implementation inside national systems.

The World Health Assembly adopted the WHO Pandemic Agreement on 20 May 2025. This agreement is a legally binding instrument intended to improve cooperation on pandemic prevention, preparedness, and response. It sits alongside the International Health Regulations as a separate instrument for pandemic cooperation.

The agreement will open for signature and ratification only after the Assembly adopts the Pathogen Access and Benefit-Sharing annex. As of May 2026, WHO Member States were still negotiating that annex and had agreed that more time was needed to finalize it. Once the agreement is open and enough countries ratify it, it will enter into force 30 days after the 60th ratification.

The Pandemic Agreement covers pandemic cooperation across several policy areas. Surveillance and One Health provisions address early warning, while health-system and workforce provisions address preparedness. Research and local production provisions address the ability to respond once a pandemic threat has emerged. Financing provisions deal with the resource side of that response.

Even so, implementation belongs to States Parties. The agreement does not give WHO authority to impose national measures such as lockdowns, vaccination mandates, or border closures. Sovereignty debates around the agreement should therefore distinguish legal cooperation among states from direct WHO control over domestic measures.

Funding and program priorities

WHO financing comes from assessed contributions and voluntary contributions. Assessed contributions are membership dues. The calculation uses each country’s share of global gross domestic product. The United Nations General Assembly agrees on the scale, and the World Health Assembly approves it every two years. Assessed contributions are predictable and flexible, but they cover a small part of the Organization’s total financing.

Assessed contributions currently cover less than 20 percent of the total budget. Voluntary contributions provide more than three quarters of financing, but they differ in flexibility. Core voluntary contributions give WHO the most institutional discretion. Thematic or strategic engagement funds are more directed. Specified voluntary contributions are the narrowest category because they are earmarked for particular purposes.

For 2022–2023, specified voluntary contributions made up 87 percent of voluntary contributions. Core voluntary contributions were 6.6 percent, and thematic contributions were 6 percent.

This financing structure creates a practical tension between WHO’s constitutional mandate and its budgetary freedom. A mandate covering many health fields requires the ability to shift resources as needs change. Earmarked voluntary money can instead steer growth toward donor priorities. It can also affect which emergencies receive support and how much room the Secretariat has to act on priorities approved by Member States. To reduce that imbalance, the World Health Assembly has approved a plan to increase assessed contributions so that they cover 50 percent of the base budget by 2030.

WHO’s 2026–2027 program budget totals US$6,206.7 million, a 9 percent decrease compared with the 2024–2025 budget. The budget separates base programs from emergency operations, polio eradication, and special programs. These budget lines operate within WHO’s Fourteenth General Programme of Work, which guides the Organization for 2025–2028. The Health Assembly adopted that program in May 2024. Its strategic direction uses the official formula “promote, provide, protect” for health and well-being.

The Fourteenth General Programme of Work sets six strategic objectives. Two objectives focus on prevention: climate-related health threats and the root causes of ill health. Two focus on health systems: primary health care capacity and service coverage without financial hardship. The remaining two focus on emergency preparedness, detection, and response.

WHO’s published targets are framed at global scale. They call for:

• 6 billion people living healthier lives;
• 5 billion people benefiting from universal health coverage without financial hardship;
• and 7 billion people better protected from health emergencies.

Limits of WHO authority

WHO has substantial technical and procedural authority within an intergovernmental system. Its recommendations guide government action during ordinary programs and emergencies. Its standards give governments a technical reference point for domestic policy. Under the IHR framework, WHO can also declare a public health emergency of international concern when the legal criteria are met. Negotiated legal instruments give WHO a role in rulemaking. However, national governments remain responsible for most domestic implementation.

International guidance becomes policy only after national institutions act. A health ministry may translate WHO guidance into administrative rules. A legislature may need to fund or authorize a program. After that, laboratories, hospitals, and emergency agencies turn those decisions into surveillance, treatment, procurement, and response capacity.

Some WHO instruments are legally binding, especially the International Health Regulations and regulations adopted under the constitutional framework. Even then, binding rules still rely on national systems for enforcement. Domestic law and administrative capacity determine whether an obligation can be carried out. Political will and reliable reporting shape whether it is carried out in practice. A state may accept obligations and still lack the practical capacity needed for full implementation.

Emergency authority is powerful because classification and recommendations can shape international attention, travel policy, aid coordination, and national risk assessment. Yet WHO emergency authority is still procedurally bounded. The Organization can assess information, declare a public health emergency of international concern when the legal criteria are met, and issue temporary recommendations. National governments decide most border, vaccination, quarantine, procurement, and health-system measures.

Political disputes usually arise where technical health judgment meets sovereignty and economic cost. Governments may disagree with the timing of WHO action, the transparency of assessments, or the wording of proposed legal rules. Donors may prefer earmarked contributions that match their own priorities. States may defend national discretion when global rules require faster reporting or deeper preparedness obligations. These disputes define the environment in which WHO authority has to operate. The Organization’s institutional role remains real, but its effect depends on cooperation from governments and donors.

The Organization’s limits are part of its design. WHO works through cooperation, standards, information, legal procedures, and delegated authority. It depends on states for most enforcement, financing, and implementation. That combination explains both its importance and its vulnerability. When governments share information, fund agreed priorities, and implement obligations, WHO can coordinate a global health response that no single country could manage alone. When cooperation weakens, the Organization’s technical authority remains real, but its practical effect becomes harder to secure.