COGS Percentage: Specialty vs General Practice

The average dental specialist kept $346,520 last year on $1,213,040 of billings. The average general dentist kept $215,320 on $965,660. That $131,200 gap is not a story about working harder, because the specialists in the data are frequently less busy than the GPs sitting across town, and it is not a story about cheaper supplies either: a good chunk of specialty practice runs a higher cost of goods percentage than the general office that refuses to place an implant.

So here is the claim, and plenty of owners who have been coached on overhead percentages for a decade will hate it. Our view: COGS percentage is a readout of your service mix, not a measure of how well you run your practice, and a general practice that has driven COGS below 12% has usually done it by referring out the exact procedures that would have paid for the next operatory. The low number on the report is not discipline. It is frequently a symptom.

Specialists Spend More Per Case and Keep More Per Dollar

Start with the aggregate picture. In the ADA Health Policy Institute's practice research, 2025 figures show general practitioners netting $215,320 on gross billings of $965,660, which puts total expenses around 77.7% of billings. Specialists netted $346,520 on $1,213,040, an expense ratio near 71.4%. Six-plus points of total cost ratio, on a bigger revenue base, compounding every year.

Now the part that should bother you. Orthodontics, one of the most material-and-lab-intensive things you can do in a dental chair, reported average practice overhead of 56.5% of revenue in the 2025 Orthodontic Practice Survey from Orthodontic Products and Levin Group, against the 60% to 67% range typically cited for general practices. Aligner trays, brackets, wires, retainers, digital scans: all of that sits inside a cost structure that still beats the average GP office by roughly a decade of accumulated profit.

The cleanest historical illustration comes from endodontics. An ADA HPI research brief on the endodontics market found average net income of $325,844 for endodontists versus $174,780 for general dentists in the 2014 Survey of Dental Practice, roughly 1.9 times a GP's income, while endodontists reported the lowest busyness levels of any specialty. Less demand pressure, more money kept. That is not a productivity story. It is a cost-per-unit-of-production story, and COGS is only one line inside it.

Put the two halves together and the pattern is uncomfortable for anyone who manages to a percentage. Specialty practices carry lower total cost ratios while some of them carry higher materials-and-lab ratios. COGS and total overhead move in opposite directions often enough that treating one as a proxy for the other is a real error with real dollars attached.

The 12% to 16% Rule Is a Floor Test, Not a Target

The standard general-practice benchmark holds up fine as a benchmark. Wicklow Healthcare Advisory puts general dental COGS at 12% to 16% of revenue, with anything above roughly 20% treated as a red flag, and notes that practices offering higher-end specialty services such as implants tend to run higher COGS percentages than standard general dentistry. Underneath that, ZenOne's 2026 overhead breakdown splits the line into clinical supplies at 4% to 6% of collections and lab fees at 6% to 8%, giving a combined COGS-equivalent of about 10% to 14% for a general office.

Read those ranges as a floor test. If supplies are at 9% of collections, you have an ordering problem, an inventory problem, or a staff-buying-off-catalog problem, and that is worth a Tuesday afternoon. If lab is at 11% of collections in an office doing bread-and-butter crown and bridge, you are either overpaying per unit or eating remakes you are not tracking.

But nobody has ever sold a practice for a multiple of their supply ratio. The number that gets capitalized is net, and net is driven by what you keep per hour the chair is occupied. The benchmark tells you whether a line item is leaking. It does not tell you whether the mix producing that line item is the right mix.

What Most Owners Get Wrong: Treating Lab Fees as Waste

The specific mistake: owners who manage COGS as a cost-reduction target rather than a mix indicator, and then make clinical referral decisions to protect the percentage.

It shows up most often in general practices eight to fifteen years in, doing $800,000 to $1.3 million, with a consultant relationship and a monthly dashboard. The owner has been trained to see 13% and feel good, 18% and feel bad. So when the implant course invoice arrives, or the lab quotes $1,300 in components and a custom abutment, the reflex is to refer the case out. The percentage stays clean. The chair time gets refilled with a $260 composite. And the owner reports, accurately, that overhead is under control.

The other version is the lab switch. Somebody pitches a 20% to 25% saving per unit, the owner moves 300 crowns a year, the report improves by a few tenths of a point, and the remake rate quietly goes from 2% to 6%. Remakes do not land in the COGS line where you would notice them. They land in chair time you already sold, which is the one input you cannot reorder.

The lowest-COGS practice in your town is usually the one that referred away its best dollars.

Two Implant Cases a Month Beats Every Lab Discount You Will Ever Negotiate

Take the ADA average GP as your baseline: $965,660 in billings, COGS at 12%, which is $115,879. Net income $215,320, per the ADA figures above.

Now add two surgical implant cases a month, 24 a year, at $4,600 each, for $110,400 in added production. Fixture, abutment, custom parts and lab run $1,250 a case, so $30,000 of new COGS. That work carries a COGS ratio of 27.2%, more than double the benchmark. Each case eats about 3.5 hours of chair time across surgical and restorative visits, so 84 hours a year. Loaded assistant time at $35 an hour over those hours adds $2,940. Rent, front desk, software and the hygiene department do not change.

Contribution from that mix shift: $110,400 minus $30,000 minus $2,940, or $77,460. That is $922 per chair hour. Blended COGS on the year moves to $145,879 on $1,076,060 of production, which is 13.6%. So the ratio worsens by 1.6 points while net income rises 36%.

Compare that against the disciplined alternative. Lab at 6% of collections is $57,940 a year. A hard-won 20% reduction is $11,588. The implant path pays 6.7 times more.

And the lab saving is fragile. If the cheaper lab moves your remake rate from 2% to 6% on 300 crowns, that is 12 extra remakes. At 1.5 chair hours each, that is 18 hours gone. Value those at $450 of production an hour and you have burned $8,100, plus roughly $180 a unit in redo lab, another $2,160. Total damage $10,260, against a saving of $11,588, leaving $1,328 for the year. You reorganized your lab relationship for the price of a decent scanner service plan.

We would not spend a single owner-hour on the lab discount before the mix question is settled. The discount is real and it is rounding.

When a High COGS Percentage Genuinely Is the Problem

None of this means high COGS is automatically fine. There are three situations where the number is telling you something true and urgent.

• High COGS on discounted fees. That $1,250 implant component set is 27.2% against a $4,600 fee. Against a PPO allowable of $3,200 it is 39.1%. Same clinical work, same materials, and the contribution per chair hour falls hard. High-COGS procedures are where write-offs do the most damage, because the discount comes entirely out of margin while the material cost is fixed. If your implant and aligner volume is concentrated in your two worst plans, the mix argument flips against you.
• Supplies drifting without a mix change. Clinical supplies climbing from 5% to 8% of collections with no new service lines is not a mix story. That is ordering, storage, expiry and shrink, and it is worth a physical count this quarter.
• COGS rising while production per chair hour is flat. This is the honest red flag. Spending more to produce the same amount means you bought materials, not cases. Above 20% with flat production, the Wicklow threshold is doing exactly the job it is meant to do.

The Metric We Would Actually Put on the Wall

Our call: replace COGS percentage as a management metric with contribution margin per chair hour, by procedure category, net of your actual payer mix. Direct materials and lab out, direct clinical labor out, divided by scheduled hours. Do it for hygiene, for single-unit crown and bridge, for surgical, for aligners. It takes an afternoon with your production report and your lab statements, and most offices find at least one category running under $200 an hour that they have been protecting because it looks cheap on the supply line.

Keep COGS percentage on the report. Read it as a diagnostic, the way you read a bitewing: it tells you where to look, not what to do. When it moves, the first question is always whether the mix changed. If it did, the ratio is doing its job. If it did not, go find the leak.

What we are watching next: whether the specialist cost advantage in the 2025 ADA data holds as implant component pricing compresses and DSO-owned specialty groups reset fee schedules in competitive metros. And what would change our mind: if three-year loaded costs on GP-placed implants, including warranty remakes, failures, retreatment and the referral relationships you spend down by keeping cases, pulled contribution per chair hour back toward what hygiene already produces. We have not seen that math yet. We are looking for it.

Do This Before Your Next Lab Statement

Pull twelve months of production by procedure code and twelve months of lab and supply invoices, and assign every material dollar to the category that consumed it. Divide each category's contribution by the chair hours it used, then sort the list. Then take your three highest-COGS procedure categories and recalculate them at your two worst plans' allowables, because that is where a defensible cost ratio turns into a losing one. Whatever sits at the bottom of that sorted list is next week's decision, and it is almost never the lab contract.

If you want a faster read before you do the full category build, our overhead benchmarking tool will put your supply and lab ratios against practices with a comparable service mix and show you where your total cost structure sits relative to the specialty numbers above. Run your own numbers, then decide whether your COGS line is a discipline story or a referral story.