What an Interim CFO Does in the First 90 Days: A 30/60/90 Plan

Key Takeaways

• An interim CFO’s first 90 days follow a clear arc: stabilize and make sure that there is a clear forecast for cash and reporting in days 1–30, diagnose and fix what the transition exposed in days 31–60, and set forward direction and prepare the handoff in days 61–90.
• The priority in week one is continuity, not reinvention. Payroll, the bank relationship, the board, and the monthly close all have to keep running while the interim learns the business.
• The 90-day plan is the front end of a longer transition. Deloitte’s work with newly appointed finance chiefs finds most need roughly six months to fully establish themselves, so the interim’s job is to stabilize now and leave the next CFO a running start.

Your CFO gives notice on a Thursday. The monthly close is due in eight days, a lender covenant certificate (a signed confirmation that you are meeting the terms of your debt) is due at month-end, and the board wants a cash update Monday morning. None of those deadlines move because the finance seat is empty. This is the moment companies bring in an interim CFO, and what that person does in the first 90 days determines whether the gap becomes a wobble or a genuine setback.

An interim CFO is a senior finance leader who steps into an open, or soon-to-be-open, CFO seat and runs the finance function for a defined period. In the first 90 days, that work follows a clear arc: days 1–30 stabilizing cash and keeping the basics running while learning the business, days 31–60 diagnosing and fixing what the departure exposed, and days 61–90 setting forward direction and building the bridge to a permanent hire. The work is sequenced on purpose. Stabilize first, then diagnose, then direct.

Why companies bring in an interim CFO

The CFO chair is one of the least permanent seats in the building. Average CFO tenure has slipped to about 4.7 years, and in 2025 the largest U.S. public companies recorded 120 CFO changes, up nearly 18% from the year before, according to Crist Kolder Associates’ annual Volatility Report. Private, founder-led companies see the same churn, often with less warning and far less bench depth to absorb it.

When the seat opens, the calendar does not pause. Payroll still runs, the audit still has a deadline, the bank still expects its reporting, and the board still wants numbers it can trust. An interim CFO, also called a temporary CFO, is the person who carries that weight for a defined stretch, usually three to nine months, while you find and onboard the permanent leader, or while you get through a specific event like a sale, a raise, or a first audit. The role is different from a fractional CFO, who works with you on an ongoing, part-time basis when there is no vacancy to fill. The interim is a bridge across a gap. Here is how a good one builds it.

Days 1–30: Stabilize the basics and learn the business

The first month is about continuity and listening, in that order. Moving fast is valuable, but making drastic changes too early can backfire. Michael Watkins, whose book The First 90 Days gave the 30/60/90 model its name, calls the urge to make a splashy early move the “action imperative,” and it is how new leaders break things they do not yet understand. The job in week one is to keep the trains running and learn the terrain.

Cash comes first. The interim builds or refreshes a 13-week cash flow forecast (a week-by-week view of money coming in and going out over the next quarter) so there are no surprises around payroll, accounts payable, or a covenant test. They confirm bank balances, the debt schedule, and which obligations are due in the next 30 days. If the departing CFO left a clear picture, this is verification. If they did not, this is the single most important thing the interim does in the first month.

At the same time, the monthly close has to stay on schedule. A close that slips in month one is hard to recover, and it is the first thing a board notices. The interim works with the controller and accounting team to get the books out on time, even if the process is rough.

Then comes the learning. The interim meets the people who matter to the numbers: the CEO, the board chair or audit committee lead, the finance team and the layer below it, the outside auditors, the lenders, and a handful of the largest customers and vendors. Often, an interim CFO will meet with the CEO or executive leadership team immediately to share preliminary strategy on day 1. McKinsey’s guidance to new finance chiefs is to treat the early days as a rare chance to ask fundamental questions about how the business actually runs, and why, rather than defaulting to how things have always been done. By day 30, the interim should have a stabilized cash position, an honest read on the finance team’s capacity, and a short list of the real fires.

Days 31–60: Diagnose and fix what the transition exposed

With cash stable and the first close out the door, the second month is where the interim earns the engagement. Transitions surface things. Reconciliations that have fallen behind. Revenue recognition treatment that will not survive an audit. A forecast no one believes. Controls that depend on the person who just left. The interim’s job now is to find these and fix the ones that carry real risk.

Reporting usually needs work. The interim gets the board package and the core KPIs (key performance indicators, the handful of metrics that actually predict the business) to a decision-ready state, so the CEO and board are steering with numbers they trust. Where the reporting was built around the departed CFO’s habits, the interim rebuilds it around the business fundamentals.

This is also when the interim assesses the team in earnest. Deloitte’s CFO Transition Lab frames a new finance leader’s work around four streams: setting and communicating priorities, building a talent strategy, mapping the stakeholders who matter, and turning all of it into concrete action. By the end of month two, the interim should know who on the team can carry more, where there is a gap to backfill, and which two or three problems need to be solved before a permanent CFO arrives. Then they solve them, and they document the work as they go.

Days 61–90: Set direction and build the bridge

The final month points forward. The interim turns the diagnosis into a plan the organization can run after they leave: an updated budget or reforecast, a working financial model, and a clear view of runway (how many months of cash the company has at its current burn). This is the model the next CFO will inherit, so it is built to be handed over, not hoarded.

At this stage, the interim CFO may also begin interviewing new team members, including the incoming permanent CFO. 

Knowledge transfer is the quiet difference between a clean handoff and another scramble. The interim leaves documentation, process maps, a current close checklist, and an organized set of working files. It is the opposite of what an abrupt departure usually leaves behind. If the company is also running a search, the interim helps write the specification for the permanent CFO hire and prepares a 30/60/90 plan for that successor, so the new leader starts with a map instead of a cold start.

A 90-day plan does not mean the transition ends at 90 days. Deloitte’s research on executive transitions makes the point that the “first 90 days” is something of a myth: most finance leaders realistically need about six months to fully establish themselves. The interim’s 90 days do the heaviest lifting in that longer arc: stabilize, diagnose, direct, then hand off to a permanent leader who can take it from there.

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What an interim CFO is not

The boundaries of the role are worth stating plainly. An interim CFO is not a caretaker keeping the seat warm until the real decision-maker shows up. They hold genuine authority and make real decisions, including ones the company has been avoiding. They are also not a permanent hire auditioning for the job, which frees them to be honest about what they find. And they are not a senior bookkeeper; the close matters, but the mandate is leadership of the finance function, not just its mechanics. The defining trait is that the role has an end date and a handoff built into it from day one.

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If your finance seat is open, or about to be, the cost of waiting is measured in missed closes, anxious lenders, and decisions made without numbers. An experienced interim CFO can step in within days and keep the business steady while you find the right permanent leader. We have done it for companies in the middle of audits, fundraises, and sales of the business. Book a CFO strategy call with Ascent CFO Solutions.

Frequently asked questions

What is the difference between an interim CFO and a fractional CFO?

An interim CFO fills a vacancy for a defined period, usually three to nine months, often close to full-time, while you transition between permanent leaders or get through a major event. A fractional CFO works with you on an ongoing, part-time basis when there is no gap to fill and you simply do not need a full-time CFO yet. We cover the distinction in more depth in fractional CFO vs. interim CFO.

How long does an interim CFO engagement usually last?

Typical engagements run three to nine months, but in some cases can run 12 months or longer. The length tracks the reason for the engagement: covering a search for a permanent CFO, bridging a parental leave, or carrying the company through an audit or transaction. 

What should an interim CFO accomplish in the first 30 days?

Stabilize cash with a current 13-week cash flow forecast, keep the monthly close on schedule, meet the stakeholders who matter to the numbers, and build an honest list of the real risks. The first 30 days are about continuity and learning, not sweeping change.Can an interim CFO run a fundraise, sale, or audit?

Yes, and companies often bring one in precisely for an event. An interim CFO with transaction experience can maintain the data room, present financials to buyers or investors, and manage the diligence process, which is common in a sale of the business. The defined timeline of the event and the interim engagement line up naturally.

How does an interim CFO hand off to a permanent CFO?

Clean documentation, an updated forecast and model, a current close process, a written specification for the permanent role, and a 30/60/90 plan for the incoming leader. A good interim measures success partly by how little the next CFO has to rebuild.

When should we hire an interim CFO instead of waiting?

If a CFO has resigned, a covenant or audit deadline is approaching, or a transaction is underway, the gap between leaders is exactly when mistakes get expensive. Bringing in an interim early protects continuity; waiting usually means paying to clean up later. If your company already has a strong Accounting Manager or Controller, an interim CFO is critical to augment the existing team.

A finance bridge that holds

A leadership gap in finance is one of the few problems that gets worse every week you leave it open. We help founders and CEOs of scaling-stage companies across the country bridge that gap without losing a step, with interim CFOs who stabilize the numbers, fix what the transition exposed, and prepare a clean handoff to your next permanent leader. Book a CFO strategy call with Ascent CFO Solutions.