When Andy Burnham ran Greater Manchester, coterminous boundaries were his argument for everything. Health, transport, housing and policing worked better, he said, when the people making decisions answered to the same geography. It was a mayoral case, made from the outside. It is a different matter to make it from Downing Street, where the pledge to align Integrated Care Boards with Strategic Authority boundaries by the end of this Parliament now lands on health systems that have already spent a year rearranging themselves on someone else's instructions.

That instruction came from NHS England, which drove a wave of ICB mergers and clustering through 2025 and into this spring on the promise of lower running costs and less duplication. Twelve boards became six. A further tranche of clustered ICBs moved toward multi-board arrangements, encouraged, in some cases pressed, to consolidate fully. Boards dissolved, executive teams were cut, redundancy and redeployment processes ran their course, and organisations that had barely finished appointing new leadership were told to start planning mergers with neighbours. All of this was justified as a one-off cost of achieving a leaner, more durable commissioning structure.

The boundary mandate now complicates that justification. Several of the newly merged or clustered ICBs do not sit neatly within a single Strategic Authority footprint, because the authority map itself is still being drawn. Local government reorganisation is proceeding on its own timetable, with some areas not expected to settle their unitary and mayoral arrangements until 2028 or later. Boards in Herefordshire and Worcestershire have already told NHS England, in board papers, that further changes ahead of that clarity would mean absorbing a second restructuring within a short period, on top of the one they have only just completed. That is not resistance to devolution. It is a system trying to avoid paying for the same reorganisation twice.

There is a coherent case for coterminosity. Shared planning between NHS commissioners and local authorities, on health inequalities, on social care integration, on public health, genuinely benefits from matching geography rather than boards straddling council boundaries or splitting communities across separate commissioning arrangements. Burnham's instinct here is not wrong in principle. The difficulty is sequencing. NHS reform has run to its own clock, driven by running-cost targets NHS England set well before the devolution map existed in its current form. Local government reorganisation is running to a slower, more contested one, shaped by boundary reviews, mayoral elections and legislation that has not yet passed. Asking ICBs to anticipate a settlement that has not happened is asking them to guess, and guessing wrong means a further round of leadership churn, board dissolution and management time diverted from the strategic commissioning role they were supposedly freed up to perform.

The people who absorb that cost are rarely the ones setting the timetable. Executive teams face renewed uncertainty over their own positions before the last uncertainty has cleared. Commissioning staff redirect attention from population health planning to organisational design for a second time in eighteen months. Provider trusts, life sciences partners and local authorities trying to build long-term relationships with a commissioner find themselves negotiating with a body whose shape may not survive the parliament. None of this shows up in the headline case for devolution, but it is where the credibility of that case will actually be tested.

For a government making the argument that Whitehall should surrender power to the regions, the ICB boundary question is a useful test of whether that argument extends to patience as well as ambition. Rewiring the state is meant to produce more coherent institutions, not institutions that are permanently mid-redesign. If Burnham's devolution agenda is to succeed in health as it did in Greater Manchester, it will need to tolerate a mismatch between NHS and local government boundaries for as long as the local government map remains unfinished, rather than forcing premature alignment onto boards that have only just stopped moving.