ICB clustering and the prospect of mergers from 2026

Integrated care boards are entering a period of significant structural change. Following recent direction from NHS England, ICBs are being asked to operate at much lower running costs, while continuing to deliver their statutory responsibilities. By December 2025, ICBs are expected to reduce their running and programme costs by 50 percent. To help achieve this, most systems have already agreed to work in clusters, with further change possible from April 2026.

Why ICBs are clustering

Clustering is intended to reduce duplication and create economies of scale. It allows two or more ICBs to work together across a larger footprint while remaining legally separate organisations.

In practice, clustering can include joint committees, shared teams, or combined senior leadership roles. The aim is to retain local accountability while reducing overheads and aligning decision making across neighbouring systems.

Over the past few months, most ICBs have confirmed clustering arrangements, developed largely on a regional basis.

Does clustering mean mergers

Not necessarily.

While clustering enables ICBs to function at lower cost, it does not automatically lead to mergers. However, once operating in a clustered model, some ICBs may choose to explore mergers as a way of sustaining those reductions over the longer term. There are several potential approaches to merger, including abolishing existing ICBs and creating a new organisation. Importantly, current cluster boundaries would not automatically become the boundaries of any future merged ICB. Any merger, or change to ICB boundaries, would require ministerial approval.

The role of strategic authorities

One factor likely to influence future decisions on ICB boundaries is the development of strategic authorities.

The government has stated in the 10 Year Health Plan that it intends to make ICBs coterminous with strategic authorities by the end of the plan, wherever feasibly possible. However, the creation of new strategic authorities and wider local government reform is expected to take place over a much longer timeframe than current ICB reorganisation. This creates a degree of uncertainty. ICBs are expected to function on their reduced cost base from 1 April 2026, even though the wider structural picture is still evolving.

Where clustering has happened

Across the 42 ICBs in England, 15 clusters have been agreed. A further 11 ICBs are not currently part of any clustering arrangement. No clustering arrangements have been developed so far in the North East and Yorkshire region, which has four ICBs, or in the North West, which has three.

What happens next

For now, clustering is the primary mechanism through which ICBs are expected to deliver cost reductions. Mergers remain a possibility rather than a certainty, shaped by local decisions, national policy, and the longer term development of strategic authorities.

What is clear is that ICBs will need to operate differently from April 2026, regardless of whether further structural change follows.