Dental Accounts Receivable Aging: The 90-Day Problem

Every dental practice has an aging report, and most owners glance at the total, note that it is a big number, and move on. The figure that actually predicts a problem is one column over: the share of your accounts receivable that has been sitting unpaid for more than 90 days. It points straight at revenue you have already produced but have not been paid for.

Here is the short version. A healthy practice keeps receivables over 90 days old under 10% of total AR. Levin Group, writing in Dental Economics, calls 10% to 20% sitting in that column dangerous, which is what puts the working line below 10%. Cross it and you are not looking at a timing quirk. You are looking at a collections problem, because the way dental collections actually work means fresh claims get paid quickly and old balances rarely get paid at all.

What the "AR Over 90 Days" Number Measures

Your aging report sorts every open balance into buckets by how long it has gone unpaid: current, 31 to 60 days, 61 to 90 days, and over 90 days. The metric that matters is the last bucket divided by the total. If your total AR is $180,000 and $27,000 of it is more than 90 days old, your AR over 90 days is 15%, and 15% is a problem.

Age matters because collectibility falls off a cliff. A balance in the current column is almost always collected in full. Once a balance passes 90 days, Levin Group puts its chance of ever being collected at under 50%, because insurers deny stale claims and patients stop responding. So the 90-day bucket is not just old money, it is money that is actively becoming uncollectible while it sits there. Reading the report correctly is a skill of its own, and it is worth learning how to read your aging report line by line before you act on it.

The 10% Benchmark: Where the Line Is

The healthy target is under 10% of total AR over 90 days. It is worth knowing where the typical practice actually lands, because it is not comfortably inside that line. The Levin Group and Dental Economics Practice Research Report measured 13% of accounts receivable sitting over 90 days across a national cross-section of general practices. That reading is from 2013 and we have not found a more recent measurement of the same metric, so treat it as directional rather than current. The shape of it still holds: the average practice sits just over the line, not under it.

There is a companion benchmark worth watching alongside it: total AR should sit at roughly one month of production, an accounts receivable ratio of about 1.0. If your practice produces $120,000 a month and your total AR is $120,000, your ratio is 1.0 and you are in good shape. Let total AR balloon well past a single month of production and you have quietly turned your practice into a bank, financing your patients and their insurers out of your own cash flow.

These two numbers move together with your collection ratio. A rising 90-day bucket is usually the first place a slipping collection ratio shows up, which is why watching the aging is an early-warning system rather than a post-mortem. If you want a fast read on where you stand, our free Dental Practice Benchmark Scorecard checks your AR, collection ratio, and overhead against healthy dental ranges in about two minutes.

Common Causes of Aged Receivables

When the 90-day bucket swells, the cause is almost always one of a short list of leaks. Nobody publishes a reliable ranking of which one is most common in dental practices, so do not waste time hunting for the biggest offender. Work them in the order below, which is built to keep you from spending a month chasing an AR report that was wrong to begin with.

First, Confirm the Number Is Real

Before you chase a dollar of it, make sure the balance exists and is being reported honestly. Skip this step and you can put real effort into receivables that were already paid or were never going to be collected.

• Posting errors. Payments applied to the wrong account leave phantom balances aging in the report that were actually paid. The money is already in the bank and the report does not know it.
• Write-offs used as a broom. Writing a balance off to tidy the ledger is not the same as collecting it, and miscoding a real collection failure as a routine adjustment hides the problem instead of fixing it. Know the difference between a write-off and bad debt before you clear anything.

Then Work the Leaks in the Order the Money Flows

Once the report is trustworthy, follow the revenue cycle from the front. A leak upstream makes everything downstream look worse than it actually is.

• Claims that went out late. Billing in weekly batches instead of within a day or two pushes every claim closer to the 90-day edge before the payer ever sees it. The ADA's own standard is that benefits arrive within 7 to 10 days of submitting a claim, and that every claim is paid and deposited within 30 days. Measure from the date of service, not from the day someone got around to billing.
• Denials nobody reworked. A claim gets denied and then no one owns getting it back out the door. The ADA lists the usual triggers: missing information, a missing or inadequate radiograph, an eligibility error, a duplicate claim, or a procedure that exceeded frequency limitations (ADA). None of those is fatal on its own. What makes them permanent is the clock, because some plans time-bar an appeal at six months from the denial. An unworked denial is not a slow payment, it is a deadline quietly running out.
• Patient balances nobody chased. The portion insurance does not cover has to come from the patient, and every week it waits, it gets less likely to arrive. This is the bucket that responds least to billing effort and most to what happens at the front desk before the patient leaves.

Insurance Claims vs Patient Balances

The 90-day bucket has two very different tenants, and lumping them together is why aged AR feels overwhelming. Split it before you do anything else.

Aged insurance AR is usually a workflow failure, not a lost cause. The claims are denied, pending, or never followed up, and a disciplined week of reworking them recovers a real share of the money, because a payer that owes you will still pay a corrected claim. Aged patient AR is harder. Once a patient balance passes 90 days with no statements and no calls, recovery is low, and the fix is upstream: collect the patient portion at the time of service, set a clear financial policy, and send statements on a schedule instead of when someone remembers. Following the American Dental Association's guidance on overdue accounts keeps the patient side from aging in the first place. When you separate the two, you can put insurance denials in front of your billing person and patient balances in front of your front desk, which are two different jobs.

Action Steps When AR Is Too Old

Bringing the number down is about ownership, not heroics. Work the aging report every week, oldest and largest balances first, so nothing crosses 90 days unnoticed. Split every aged balance into insurance versus patient and assign each pile to the person who can actually move it. Treat 90 days as a hard red line: anything approaching it gets a call this week, not next month. Collect the patient portion at the time of service so it never enters the report. Then watch your AR over 90 days monthly against the 10% benchmark, the same way you would watch a vital sign, and you will catch a slip while it is still small enough to fix.

P.S. Reciprocity Accounting tracks AR over 90 days in your monthly dashboard, reconciled to your practice’s aging report, on books that close by the 10th, so a rising 90-day balance shows up while it is still collectible instead of after it is gone. See how we can help your practice.

Frequently Asked Questions

What is a good AR over 90 days percentage for a dental practice?

Under 10% of total AR is the healthy line. Anything consistently above 10% signals that claims and patient balances are aging past the point where they get paid, which is a collections problem rather than normal timing.

How much of my over-90-day AR can I actually collect?

Far less than the fresh column. Levin Group puts the chance of collecting a balance past 90 days at under 50%, because insurers deny stale claims and patients stop responding. That steep drop-off is exactly why the goal is to keep balances from reaching 90 days at all.

Is my aged AR an insurance problem or a patient problem?

It is almost always some of both, and you cannot fix it until you separate them. Aged insurance AR is usually unworked denials, which a disciplined week of follow-up can recover. Aged patient AR is balances that were never collected at the time of service, which points to your financial policy and front-desk process, not your billing.

Does a high AR over 90 days mean my collection ratio is bad too?

Usually, yes, and the aging report tends to warn you first. A growing 90-day bucket is money you produced but have not collected, so it drags your collection ratio down as those balances age. Watching the two together tells you whether a low collection ratio is simple insurance lag or a real backlog of stuck money.