Drift vs. Erosion: How to Tell a Cost Problem You Manage From One You Exit

A general practice collecting $1 million in 2021 that did nothing wrong, held every cost line to the national average, and left its PPO fee schedules untouched is about $51,300 a year poorer in owner income today. Not one invoice was mismanaged. The money left through a door nobody was watching, because the owner spent four years auditing the supply cabinet.

Here is the claim, and plenty of owners will fight it: almost nothing on your expense sheet is actually eroding. Staff wages, supplies, equipment, the lines that generate the most anguish in study clubs, are drifting up at a rate slightly below general inflation, which makes them a pricing problem you already know how to solve. The genuine erosion sits on the revenue side, in contracted rates that have not moved since before the pandemic. Cost-cutting feels like action. On the line that is actually bleeding, it is a displacement activity.

The Test: Can One Fee Cycle Close the Gap?

Drift vs. Erosion is a classification, not a mood. Take any adverse trend in a cost you pay or a rate you collect, and sort it into one of two bins.

• Drift is small, steady and recoverable. The line rises at or below the rate you can raise your own realized collections per visit, and the gap closes within one fee cycle using an adjustment you could genuinely take without losing the patient. You manage drift operationally: negotiate, substitute, reprice, move on.
• Erosion is structural and compounding. The gap cannot be closed by any fee increase available to you, because the price is set by someone else's contract or by a market you do not control. Erosion requires renegotiation, repricing or exit. It does not respond to discipline.

The operative number is the recovery increase: divide the dollar gap by the collections base you are actually free to reprice. If that percentage is something you could put through this quarter, it is drift. If it is a number no payer would ever sign, it is erosion, and every month you spend "tightening up" is a month of compounding.

Treating erosion as drift is the expensive mistake, and it is expensive in a specific way: it is slow. Nobody notices a practice losing four points of margin over four years. They notice it at valuation.

Why 23% Beats 27%

Start with the baseline, because almost every owner has it backwards. Since January 2021, dental staff hourly earnings have risen 23% and dental equipment and supply prices have risen 23%, against 27% overall inflation over the same period, according to the ADA Health Policy Institute's State of the U.S. Dental Economy.

Read that again. Your two loudest cost complaints have grown more slowly than the dollar has shrunk. In real terms, staff and supplies got marginally cheaper. That is the textbook definition of drift: steady, broad, and fully recoverable by any practice willing to price at the rate of the economy it operates in.

And practices are pricing. Two-thirds of dentists reported raising fees since the start of the year, and dental practice prices are now rising faster than general inflation, per ADA News. That is the profession collectively recognizing drift and managing it, exactly as it should.

So why does the squeeze keep tightening? Because a fee increase only touches the part of your book where you set the fee. If 60% of your collections run through contracted schedules, a 27% fee increase moves 40% of your revenue and zero percent of the rest. The average holds. Your practice does not.

The $51,300 Hole That Supplies Didn't Dig

Run it. A general practice collected $1,000,000 in 2021 on a 70% overhead: staff payroll $280,000, supplies $60,000, lab $80,000, rent $70,000, and everything else $210,000, leaving $300,000 of owner earnings.

Roll each line forward four years. Staff payroll at the national 23% becomes $344,400. Supplies at 23% becomes $73,800. Assume your lab invoices came in at 20% and your lease renewal added 12%: lab becomes $96,000 and rent becomes $78,400. Everything else tracks general inflation at 27%, becoming $266,700. Total overhead is now $859,300.

Now the revenue side, same patients, same mix, same chairs. The 40% of collections you price yourself went up 27% with the economy: $400,000 becomes $508,000. The 60% running through PPO schedules that have not been revised since 2021 stays at $600,000. Total collections: $1,108,000. Owner earnings: $248,700. That is $51,300 gone, a 17% cut in what the owner takes home, with no clinical or operational failure anywhere in the practice.

Here is the part that should sting. Supplies are now running at 6.66% of collections, over the ADA-recommended benchmark of up to 6% of the prior month's collections cited by Dental Economics, which notes some benchmarks run as high as 8%. Suppose you fix it perfectly, switch vendors, tighten inventory, and land exactly on 6%. That is $66,480, a saving of $7,320.

Perfect supply discipline recovers 14 cents of every dollar you lost. Flawless execution on the line you can fully control returns one seventh of the problem. That is drift, correctly managed, and it is nowhere near enough.

Try filling the hole with volume instead. If an added visit collects $300 and carries roughly 35% variable cost, it contributes $195. Closing $51,300 takes 263 extra visits a year, about five and a half more per week, every week, forever.

Now price the erosion directly. To close $51,300 on a $600,000 contracted base, those schedules would have to rise 8.55%. No payer is writing that letter. The recovery increase is unavailable, which is precisely what makes this erosion and not drift.

Owners Audit the Line They Can Control, Not the Line That's Bleeding

The mistake has a signature, and it is made most often by the best operators: the detail-minded owner-dentist who runs their own numbers, reads the overhead benchmarks, and takes personal responsibility for every category. Rising overhead ranked among the top three challenges facing practices in HPI's 2024 survey, as Dental Economics reports, and that framing sends conscientious people straight to the expense sheet.

The expense sheet is where they stay, because it is the only part of the P&L that responds to effort. You can call a supply rep on Tuesday and see a result on Thursday. You cannot call a payer on Tuesday. So the practice runs a supply audit, converts to generics, renegotiates the lab, saves $9,000, and feels competent, while a structurally underpriced contracted book quietly takes another year off the enterprise value.

Our view: for most practices, the monthly supply-benchmark review is the least valuable hour on the calendar. Not worthless, just badly out of proportion. Set a category target once a year, delegate the enforcement, and spend the reclaimed attention on the two or three payer contracts that actually set your ceiling.

When the Plan Block Is the Erosion

Once a line classifies as erosion, the question stops being "how do we absorb this" and becomes "renegotiate, reprice, or leave." For a contracted patient block, run the Break-Even Retention Test: divide net collections per visit under the plan by net collections per visit out of network. That quotient is the share of those patients you must keep for collections to stay flat.

Say the worst plan in the scenario above nets $214 a visit and the same procedures net $340 out of network. Break-even retention is 63%. Keep more than 63% of those patients and leaving wins outright, before counting the chair time freed up by not doing 37% of the volume. Keep less and you stay and renegotiate.

On a plan at 63% break-even in a market where you are the established practice, we would drop it. Practices routinely retain 70% to 80% of a mature patient block through a well-run transition, and the ones that lose more usually announced it badly rather than priced it badly. What we would not do is drop a plan at an 85% break-even and call it strategy.

Wages Are Drift With a Floor Under Them

One caution, because the wage line is drift today and could reclassify tomorrow. Median annual pay for dental hygienists was $98,100 in May 2025 with employment projected to grow 8% from 2025 to 2035, per the BLS Occupational Outlook Handbook. Dental assistants were at $48,070 with 7% projected growth, per BLS.

Growing demand for both roles means there is no relief coming on the labor side. But growing steadily at a rate below general inflation is still drift, and drift gets budgeted, not agonized over. Build 3% to 4% annual wage growth into next year's plan, decide in advance which fee adjustment pays for it, and stop treating each individual raise as a crisis requiring a crisis meeting.

Where This Classification Falls Apart

Drift vs. Erosion is a tool for trends, and it breaks in four situations.

• Lumpy costs. A CBCT, a roof, a new operatory. These are capital events with an amortization schedule, not trends. Do not run them through this test.
• Volume masquerading as cost. If supplies jumped as a percentage of collections because collections fell, you have a production problem wearing a cost problem's clothing. Always classify on absolute dollars first, ratios second.
• A distorted base year. If 2021 staffing was abnormally thin or subsidized, your four-year growth rate is measuring a return to normal, not a trend.
• Step functions hiding inside small lines. Rent looks like gentle drift right up to the renewal that resets it 30% in a single month. Any line with a contract expiry inside 24 months gets classified on the renewal number, not the current one.

What would change our call: a sustained reversal in the HPI series. If dental staff earnings growth crosses above general inflation and holds there for four straight quarters, wages stop being drift and become structural erosion, and the right response shifts from budgeting to redesigning the hygiene model. We are watching that gap every quarter. Right now it is four points in your favor.

Classify Four Lines Before Friday

Pull 2021 and current-year figures for your four biggest cost categories and compute the growth rate on each, then compare every one against the 23% and 27% reference lines. Any line under 27% is drift: set an annual target, delegate it, and stop reviewing it monthly. Then calculate what share of your collections came from contracted schedules that have not been revised since 2021, and divide your margin gap by that base to get the recovery increase you would need. If that number is above 5%, you are not managing a cost problem, you are subsidizing a payer, and the next call belongs on your contract list rather than your supply rep.

If you want to see where your own overhead sits against the drift baseline before you start reclassifying lines, run your own numbers through our free overhead calculator. It breaks your practice into the same categories used above, so you can spot in about five minutes which lines are drifting and which are eroding.