The Leadership Gap Nobody Plans For
Every organization plans for growth and risk. However, very few plan for the moment a senior executive exits the business.
And yet, based on the data, that moment arrives with considerable regularity.
According to Spencer Stuart's 2025 CMO Tenure Study, the average tenure of a Chief Marketing Officer at S&P 500 companies now sits at 4.1 years, down slightly from 4.3 years in 2024, and still below the broader C-suite average of around five years. For CFOs, Russell Reynolds Associates' Global CFO Turnover Index reported that average outgoing CFO tenure fell to 5.8 years in 2024, a six-year low, before ticking up marginally to 6.1 years globally in 2025. In the FTSE 100 specifically, average CFO tenure dropped to just five years in 2025, a seven-year low.
Only a handful of organizations treat executive transition as a standing governance concern rather than an occasional emergency.
This article is about what happens in the gap and why the fractional model offers something the traditional response doesn't.
What is the Transition Gap?
When a senior executive leaves, the instinct is to move quickly. Post the role, brief the search firm. manage communications and internally, reassure the team that things will continue smoothly in the interim.
The gap between the exit and the search is where the cost accumulates.
McKinsey research has consistently found that most incoming leaders take well over three months to get up to speed, and at least six months before they have meaningful organisational impact. A permanent executive search, conducted properly, without rushing typically takes nine to twelve months from brief to start date. That means a business can reasonably expect to operate without full senior leadership capability in a critical function for the better part of a year.
The financial and operational consequences of that gap are well documented. Research cited by leadership advisory firm BTS estimates that a failed executive transition can cost several times the departing leader's annual salary, when you account for lost productivity, re-recruitment costs, and missed strategic progress. Separately, Forbes research has found that teams facing a leadership change face a 40% increase in attrition risk within six months.
These are not edge cases and yet the standard organizational response to an executive departure would be to redistribute the workload, appoint an acting lead from within, and wait for the permanent hire.
Three Choices, and What Each One Actually Costs
When a senior executive exits, organizations face a choice that rarely gets framed clearly enough to make well.
Rush the permanent appointment. The pressure to fill the seat is definitely there. It may be coming from the board, team, from customers who notice the absence. Rushed hiring decisions under this kind of pressure produce a predictable outcome: a hire made to resolve discomfort rather than to optimise fit. External executive hires fail at a rate of 47%, according to research aggregated by Flair HR. Rushed ones fail at higher rates still. The cost of repeating the process is significant in every dimension, financially, operationally, and culturally.
Redistribute the workload. The most common response. Someone capable absorbs the function on top of their existing responsibilities. In the short term, this looks like resilience. Over three to six months, it looks like burnout, lower output across two roles, and a senior person who is now a retention risk. The function that was vacated tends to operate at a fraction of its previous effectiveness, because the person absorbing it is not doing it full-time and may not be a specialist in it.
Maintain momentum with interim, fractional leadership. An experienced interim executive steps into the function, owns it fully, and operates as a genuine member of the leadership team while the permanent search runs properly, without time pressure. This is the option that most organizations underuse, and the one that the data most consistently supports.
Fractional leaders can typically be placed within one to two weeks, compared to nine to twelve months for a permanent hire. They arrive with the specific experience the moment requires - a CFO who has managed a restructure, a CMO who has navigated a rebrand, a COO who has led a merger integration. And because their engagement is time-bounded, they have no interest in territory or politics. Their focus is entirely on the work.
If you are new to the fractional model, we have written a comprehensive playbook detailing what the fractional model is, the benefits, when not to choose, cost comparisons between a full time, consultant and fractional hires.
The Unique Problem With CMO and CFO Transitions Specifically
Not all executive transitions carry the same risk profile. The CMO, CISO and CFO roles are worth examining separately, because the nature of their impact and therefore the nature of the transition gap is distinct.
The CMO transition gap tends to manifest as strategic drift. Marketing is a function that loses coherence quickly without senior leadership. Campaigns continue because they were already in-flight. Agency relationships carry on because they're contractual. But the strategic layer, the decisions about where to invest, what to prioritise, how to position the business through a period of change goes quiet. Without someone owning those decisions, marketing activity continues but marketing direction does not. Three to six months of that drift is genuinely difficult to recover from.
Spencer Stuart's research notes that when CMOs depart, the role itself is frequently redefined - what the incoming executive is being asked to do often looks different from what the departing one was doing. That redefinition takes time, and it creates a transition gap that is not just about the person who left but about the organisation's clarity on what it actually needs next.
The CFO transition gap tends to manifest as financial opacity. The outgoing CFO typically holds a significant amount of institutional knowledge such as the nuances of the financial model, the key assumptions in the forecast, the relationships with lenders or investors, the context behind the numbers. When they leave, that knowledge doesn't transfer automatically. An acting finance lead who is not a CFO-level operator cannot fully replace it. The board and the CEO end up making decisions with less financial clarity than they had before often without fully recognising that the clarity has degraded.
The Russell Reynolds data points to something else worth noting: 60% of CFO departures in 2025 were driven by retirement, and the average retirement age has dropped to 56.6 years, the lowest in six years. This means many CFO transitions are not crisis-driven but are, to some extent, predictable. And yet only 25% of North American CFOs, according to Deloitte research cited by Russell Reynolds, have a formal succession plan in place.
See how senior specialists can plug into your team with ease.
What the Fractional Model Offers That Consulting Doesn't
When organisations face significant transitions or major initiatives, the historical default has been to engage a consulting firm. The consulting model has strengths: it brings analytical rigour, structured frameworks, and an outside perspective that can be valuable in specific moments.
What it doesn't provide is operational ownership.
A consulting engagement produces a deliverable or advice. A fractional engagement produces outcomes. The distinction sounds subtle but it matters enormously in practice.
An interim executive from a fractional model is embedded in the business. They adapt to the systems. They attend the leadership meetings. They manage the team and make the decisions that need to be made. They carry accountability for the function's performance not for the quality of a report or the clarity of a recommendation, but for the results the function produces while they are in it.
This is what the transition period actually requires. Not advice on what the next permanent hire should do. Not a framework for how the function should be organised. But someone who is doing the job, fully, accountably, and with the experience to do it well while the organisation takes the time it needs to find the right permanent leader.
Learn more about the difference between fractional model and consulting and when to choose what.
What Good Interim Leadership Does
The value of a well-placed interim executive is not primarily about maintaining the status quo. It's about maintaining momentum and in some cases, creating conditions that a permanent hire will benefit from significantly.
The best interim engagements accomplish three things simultaneously:
They stabilise the function. The team has a clear leader and decisions are made without blockers. Priorities are set. The work continues at the level it needs to. Stakeholders both internal and external have someone accountable to engage with.
They advance the agenda. A good interim keeps moving things forward. A CFO interim might complete a refinancing the departing executive had initiated. A CMO interim might run a campaign that was in planning. An operations interim might deliver a technology implementation that was underway.
They inform the permanent hire. One of the underappreciated benefits of interim leadership is the clarity it creates about what the role actually needs to be. An interim who has run the function for six months knows precisely where the gaps are, what the function needs from its permanent leader, and what the incoming executive will inherit. That intelligence, handed over properly, shortens the new hire's ramp time significantly and improves the quality of the hiring decision itself.
How Ancore Partners Approaches Interim Executive Engagements
Ancore Partners provides embedded fractional specialists across finance, marketing, cybersecurity and operations. In the context of executive transitions, that means a senior operator who steps into the function, owns it fully, and works as a genuine member of the leadership team, not as an external adviser.
The distinction we find matters most to the organisations we work with: an Ancore specialist is accountable for the function's performance, not for the quality of the recommendations about it. Ancore specialists manage the team, attend the leadership meetings and make the decisions. The accountability is operational, not advisory.
Engagements are structured around what the moment requires. A business navigating a CFO departure during a fundraise needs something different from a business that has just lost a CMO and needs to maintain brand momentum through a product launch. We build the engagement around the specific situation.
The businesses that benefit most are those preparing for investment, managing a period of rapid growth, recovering from an unexpected departure, or navigating a strategic inflection point that requires senior functional leadership the permanent hiring process cannot yet provide.
You can learn more about how Ancore structures interim engagements atancorepartners.com or see some of our case studies.
Frequently Asked Questions
What is interim executive leadership and how is it different from a consultant? An interim executive takes operational ownership of a function such as managing the team, making decisions, and carrying accountability for outcomes for a defined period. A consultant advises on what should be done and produces a deliverable. The interim does the work. In a transition period, the difference is significant: the function needs to be led, not advised.
How long does an interim executive engagement typically last? Most interim assignments run between three and twelve months, depending on the complexity of the situation and the timeline for a permanent hire. For straightforward transitions, six months is a common duration. For more complex situations - a restructure, a fundraise, a merger integration - the engagement may run longer.
Is fractional executive support the same as interim leadership? They share the same core model, a senior specialist embedded in the business on a part-time or time-limited basis but they serve different moments. Fractional support is typically ongoing, structured around a business that doesn't yet need a full-time senior hire. Interim leadership is specifically designed for the transition period between permanent appointments, or for a defined strategic initiative.
How quickly can an interim executive be placed? In most cases, an experienced interim can be placed within one to two weeks. This contrasts with nine to twelve months for a permanent executive hire and is one of the primary advantages of the model during a transition period.
What happens to the team during an executive transition without interim support? The evidence is fairly consistent. Teams facing leadership changes without interim support experience increased attrition risk, Forbes research puts this at around 40% within six months as well as delayed decisions, stalled projects, and reduced output across the function. The team absorbs uncertainty in ways that are difficult to reverse once a permanent hire arrives.
How does an interim executive hand over to a permanent hire? A well-structured interim engagement includes a deliberate handover phase. The interim documents the state of the function, the decisions made, the priorities established, and the key context a permanent hire will need. This shortens the incoming executive's ramp time significantly and is one of the underappreciated benefits of the model.
When should an organisation consider fractional or interim support rather than an internal acting appointment? When the function is critical enough that reduced effectiveness carries meaningful business risk. When the person being asked to act up is already carrying a full role. When the transition period is likely to extend beyond three months. And when the strategic moment, a fundraise, a growth phase, a significant initiative, requires senior capability rather than senior capacity.