Dental Practice Cash Reserves: How Much Is Enough

A $1.2 million practice carrying a $650,000 acquisition loan and a household that needs $14,000 a month moves roughly $84,000 of real cash out the door every thirty days. Most owners in that seat are holding $60,000 in the operating account and calling it a reserve. It isn't a reserve, it's a float: one slow August, one dead sterilizer, or one payer handing over a worse fee schedule, and they are two payrolls away from signing something they would have laughed at in March.

Our view: the standard advice to keep three months of operating expenses is the wrong instruction. Not because three months is too little, but because "operating expenses" is the wrong thing to multiply. The number that sinks practices doesn't appear on the P&L. The target should be about two times monthly cash burn, meaning overhead plus full debt service plus what you personally have to draw to keep your own lights on. Informed owners will argue with that, and the argument is fair: two months of true burn lands below the three-month overhead figure for a debt-free practice and well above it for one carrying heavy loan payments. That's the point. The multiple was never the problem. The denominator is.

Three Months of What, Exactly

The cleanest version of the conventional rule comes from Highland Financial Advisors, which recommends at least three months of operating expenses, calculated by pulling trailing-twelve-month operating expenses off the P&L, dividing by twelve for an average month, and multiplying by three. It's a defensible floor and it has the virtue of being computable in ten minutes.

A more useful frame comes from Uluru Advisors, which tiers the target: one month of overhead at the low end, two months of average monthly overhead as a medium target, and roughly two times the sum of monthly overhead, personal cash needs, and monthly debt service at the high end, illustrated with example figures of $60,000, $120,000 and $164,000. Note what happens between the middle tier and the top one. The dollar figure barely moves, but the contents change completely. The middle tier protects the practice. The top tier protects the owner's ability to make decisions.

Our call: the high tier is the baseline, not the ceiling. Anything below it is a practice reserve, not an owner reserve, and the two fail at different moments. A practice reserve covers a bad month of production. An owner reserve covers the month production is fine and the problem is the loan, the landlord, and a kid's tuition hitting in the same week.

$132,000 Feels Like a Quarter and Buys You 47 Days

Run it on a real shape of practice. Collections of $1.2 million, so $100,000 a month. Operating expenses off the P&L, excluding owner compensation and excluding debt service, total $744,000 for the trailing twelve, which is $62,000 a month.

Straight Highland method, three months of that, is $186,000.

Almost nobody actually banks that, because the owner reasons their way down. If things get slow, supplies and lab drop, hygiene hours get trimmed, the part-time assistant goes to three days. So they strip the variable costs and reserve against fixed overhead only: rent at $7,000, core payroll they would never cut at $28,000, and $9,000 for insurance, software, utilities and the marketing they're afraid to stop. That's $44,000 a month, and three months of it is $132,000.

Now price the actual burn. Overhead of $62,000, debt service of $7,715 a month on a $650,000 loan amortized over ten years at 7.5%, and $14,000 of personal fixed cost, comes to $83,715 a month.

Divide the $132,000 by that and the three-month reserve is 1.58 months of real runway, call it 47 days.

Three months on the spreadsheet is seven weeks in the bank. That's the whole problem in one line. Two times true burn gets you to $167,430, round it to $168,000.

The gap between what that owner has and what we'd want them to have is $36,000.

Funded over twelve months, that's $3,000 a month, or 3% of collections, which is roughly one additional crown a week or one fewer bad hygiene no-show policy.

The honest counterargument: throw that $36,000 at the 7.5% loan instead and save about $2,700 a year in interest.

We'd take the cash. $2,700 is a rounding error against the cost of the decision you'll be forced into without it.

What Most Owners Get Wrong: They Reserve Against the P&L Instead of the Bank

The specific mistake is using the operating expense line as the basis for the reserve. It's made most often by owners five to twelve years in, the ones who are good at this: healthy collections, overhead under control, a CPA who gives them a clean year-end package and the three-month rule as a parting gift. The P&L is an accrual document built to measure profit. It carries interest but not loan principal. It carries depreciation, which is not cash, and omits the equipment note, which is. It says nothing about the owner's mortgage, estimated tax payments, or the fact that a solo owner's household and practice share one checkbook in practice even when they don't on paper.

The second version of the mistake is subtler and worse: treating the reserve as a balance in the operating account. If the money lives where payroll clears, it isn't a reserve, it's a cushion you'll spend without a decision. Owners who hold $90,000 in operating never actually know their reserve, because the number moves $40,000 between the fifth and the twenty-fifth of every month. Move it to a separate account at a separate institution. The friction is the feature.

A Line of Credit Is Not a Reserve

The most common substitute for cash is a $150,000 line of credit, undrawn, and the owner sleeps fine. We wouldn't. A line is a promise from a lender who gets to reassess the promise exactly when you need it, which is when your deposits have dropped, your debt service coverage ratio has slipped, and your tax return looks worse than last year's. Lines get reduced, repriced, or converted to term debt on the lender's schedule, not yours. Treat an undrawn line as a second layer, useful for a sudden equipment failure, worthless as the thing standing between you and a forced decision.

Cash in a separate business savings or treasury account is the only reserve that cannot be revoked. Hold the cash and keep the line. They do different jobs.

The Reserve Is a Negotiating Position

Here's what the extra $36,000 actually buys, in one concrete form. Say one PPO contributes $190,000 a year in collections at a 32% write-off, and you want out. Assume dropping it costs you 40% of that plan's patients, so $76,000 of annual collections walks.

At 30% variable cost on that production, the contribution you lose is $53,200.

If it takes a year to backfill those chairs with fee-for-service and better-paying plans, the hit averages $4,433 a month.

That exit consumes about 32% of a $167,430 reserve.

Which means the reserve isn't a safety blanket, it's the budget for the single highest-return decision most PPO-heavy owners will ever make. Owners without it don't decline bad fee schedules. They sign them, then spend four years explaining to their spouse why production keeps climbing and the household doesn't feel it.

The 5% Supply Creep Keeps Resetting Your Target

A reserve set in 2023 is worth less today, and not by a little. Per BLS data cited by the ADA Health Policy Institute, prices for dental equipment and supplies were up 5% from the beginning of 2025 as of September 2025, while dental reimbursement rates are not keeping pace with inflation. That's a squeeze on both ends: the cash leaving is growing, the cash arriving isn't.

On a $1.2 million practice with supplies running near $78,000, 5% is about $3,900 a year of pure erosion.

On a $120,000 equipment package, it's about $6,000 more than the same package cost in January 2025.

Owners feel this. In the ADA HPI Q4 2025 economic outlook, 41.5% of dentists surveyed named increasing expenses and overhead costs, including staff wages and benefits, supplies, equipment, rent and utilities, as one of the top three challenges heading into 2026, ranking third behind insurance issues at 55.3% and staffing at 54.2%. Note that the top three are all the same problem wearing different hats, and all three get solved by having enough cash to hold a position for six months.

Practical consequence: recompute the target every twelve months off fresh trailing numbers. A static dollar goal silently shrinks.

When We'd Hold Less Than Two Months

We're not arguing for hoarding. Past two times true burn, the next dollar has a better job: killing high-rate debt, funding a second operatory, or a down payment on the building you're currently renting. Owners sitting on six months of cash are usually avoiding a decision, not managing risk.

We'd also go lighter in a few specific cases. A debt-free practice whose owner has a spouse with W-2 income and family health benefits can reasonably run at one and a half months of burn, because the household leg of the burn calculation is already covered by someone else's payroll. So can an owner with a long-tenured hygiene column, a landlord relationship that has survived one renegotiation, and no equipment older than six years. What we would not accept is a sub-two-month reserve alongside recently refinanced debt, a single associate carrying 30% of production, or a payer mix where one plan is more than 15% of collections.

What would change our mind on the whole framework: a lender offering committed, non-cancelable, reasonably priced standby credit to solo practices. That product would make cash hoarding genuinely inefficient, and we'd cut the target to one month of burn the week it exists. We're also watching whether the equipment and supply line keeps climbing through 2026 and whether any meaningful PPO fee schedule movement shows up in next year's renewals. If reimbursement finally tracks costs, the required buffer gets smaller. We're not betting on it.

Three Moves Before Friday

Pull your trailing twelve months of operating expenses, divide by twelve, then add your real monthly debt service, including principal, and the number you personally have to draw. Multiply by two and write that figure on a sticky note, because that's your target and it's probably bigger than you expected. Open a business savings account at a bank that is not your operating bank, move whatever you can spare today, and set an automatic transfer for the day after your largest monthly deposit lands. If the gap looks like twelve months of $3,000, that's a funding plan, not a crisis.

Most owners discover the gap is an overhead problem in disguise, because a practice that can't spare 3% of collections for a year has a cost structure issue, not a savings issue. Find out which one you have: run your own numbers through our free overhead calculator, get your true monthly operating cost from your own P&L, and then multiply. A reserve isn't idle money. It's the price of being able to say no.