Bookkeeper vs controller vs fractional CFO: what does a practice need?
A bookkeeper records what happened, a controller makes sure the numbers are right and on time, and a fractional CFO turns those numbers into decisions about cash, margin, and where the practice is headed. They are not the same job and they are not a choice of one. Most $5 to $50 million practices need reliable bookkeeping first, a controller's rigor as they grow, and a CFO's judgment when the money decisions get large. A fractional CFO works alongside your bookkeeper and CPA, not on top of them.
01 · The three roles, side by side
How the three roles compare
Three jobs, three different questions. The bookkeeper answers what happened, the controller answers is it right, and the CFO answers what should we do about it.
Bookkeeper
- What they own
- Records transactions. Categorizes expenses, reconciles accounts, runs payroll entries, keeps the ledger current.
- Roughly what it costs
- Lowest of the three. Usually part-time, hourly, or a monthly bookkeeping fee. Exact cost varies by market and hours.
- When a practice needs one
- From day one. Every practice needs the books kept, no matter its size.
- What they do NOT do
- Does not interpret the numbers, forecast cash, or steer the business. Recording is not deciding.
Controller
- What they own
- Owns accuracy and the close. Enforces process, tightens controls, produces clean, on-time financial statements you can trust.
- Roughly what it costs
- Mid. A salaried hire in many growing practices, or a fractional or outsourced role. Below a CFO, above a bookkeeper.
- When a practice needs one
- As volume and complexity grow: multiple sites, more entities, a close that keeps slipping, numbers no one fully trusts.
- What they do NOT do
- Does not set strategy, model the future, or lead a financing or a sale. Controllers look backward with precision.
Fractional CFO
- What they own
- Turns the numbers into decisions. Cash forecasting, margin analysis, pricing and payer economics, financing, sale readiness, the seat that steers.
- Roughly what it costs
- On the site's market framing, $90,000 to $150,000 a year, versus $275,000 to $500,000 all-in for a full-time CFO. Koen starts with the $7,500 Margin Map.
- When a practice needs one
- When the money decisions get large and slow: unclear margin, a cash squeeze, a growth or financing move, or a sale on the horizon.
- What they do NOT do
- Does not do the bookkeeping or file your taxes. A CFO works with those roles, it does not replace them.
Cost figures for bookkeeping and controllership vary widely by market and hours, so they are described relatively here. The only fixed, guaranteed number is Koen's own: the $7,500 Margin Map.
02 · Not a choice of one
These roles work together
The common mistake is treating this as a hiring decision where you pick one. You do not. A practice needs its transactions recorded, its close verified, and its money steered. Those are three functions, and a healthy finance operation has all three running.
Koen works alongside your bookkeeper and your CPA. The engagement plugs a CFO's judgment into the team you already have. Your bookkeeper keeps recording, your CPA keeps filing, and the CFO layer turns their output into decisions about cash and margin. Nobody gets replaced.
If you are still deciding whether the CFO seat is the gap, read what a fractional CFO costs, the pillar guide to fractional CFOs for medical practices, or the results from a real practice.
03 · Straight answers
Questions owners ask
What is the difference between a bookkeeper, a controller, and a CFO?
A bookkeeper records transactions and keeps the ledger current. A controller owns accuracy and the monthly close, producing statements you can trust. A CFO uses those numbers to make decisions: cash forecasting, margin, pricing, financing, and sale readiness. Recording, verifying, and deciding are three different jobs.
Do I need all three, or can one person do it?
In a small practice one person may wear more than one hat, but the functions are distinct. As a practice grows past a few million in revenue, the seams show: the bookkeeper is buried, the close slips, and no one is steering the money. Most $5 to $50 million practices are better served by keeping bookkeeping, controllership, and CFO leadership as separate, complementary functions.
Does a fractional CFO replace my bookkeeper or CPA?
No. A good fractional CFO works alongside your existing bookkeeper and CPA. The bookkeeper keeps the records, the CPA handles tax and compliance, and the CFO turns the numbers into decisions. Koen is built to plug into the team you already have, not to rip it out.
When should a medical practice hire a fractional CFO instead of a controller?
Hire a controller when the problem is accuracy and timeliness: the close is late, controls are loose, the numbers are not trusted. Hire a fractional CFO when the problem is decisions: you cannot see your true margin, cash feels tight without a clear reason, or you are heading into a financing or a sale. Many practices eventually want both.
What does the Margin Map cost, and how does it fit?
The Margin Map is a fixed $7,500 over 3 weeks. It is the low-risk way to get a CFO's read on your practice without committing to a retainer. It is guaranteed to identify at least $22,500 in margin opportunities, three times its fee, or you do not pay. It works with your current bookkeeper and CPA, not against them.
How much does a fractional CFO cost compared to a full-time one?
On the site's own market framing, a full-time CFO runs $275,000 to $500,000 all-in, while fractional CFO work runs $90,000 to $150,000 a year, depending on practice size and scope. For a fuller breakdown, see the fractional CFO cost guide.
Start here
Find the gap before you fill a seat
The Margin Map is a fixed $7,500 over 3 weeks. It shows you whether the missing role is a controller, a CFO, or just cleaner numbers, and it is guaranteed to find at least $22,500 in margin opportunities or you do not pay.