Quick answer: For most medical practices, less than 10% of total A/R over 90 days is a strong position; 10–15% is worth watching; 15–20% means meaningful aged A/R is accumulating and leadership should know exactly why; over 20% warrants a deeper review of denials, follow-up, credentialing, patient balances and claim submission. Across AMS Solutions’ active client base, A/R over 90 days runs under 10%; AMS’s 2026 benchmark report cites an industry reference of roughly 13.5%. Calculate it by adding the 91–120 and over-120-day buckets and dividing by total billed A/R. But the percentage alone is not a diagnosis — you also need the trend over six months, the breakdown by payer, the dollars (not just the percent), and what is actually sitting in the aged balances.
You pulled your accounts receivable aging report. There is money in the 0–30 day bucket, more in 31–60, some in 61–90. Then you reach 91–120 days and over 120 days, and the obvious question appears: how much A/R over 90 days is too much? This article explains how to calculate the number, what it can and cannot tell you, why A/R gets old, and what to ask when the answer is “we’re working it.”
What “A/R over 90 days” actually means
Accounts receivable is money still owed to the practice for services already provided. A typical aging report separates balances into 0–30, 31–60, 61–90, 91–120 and over-120-day buckets. HFMA’s MAP Keys define aged billed A/R using these same categories and, for ambulatory and physician organizations, age receivables from the date of service; the metric is a trending indicator of receivable aging, collectability and revenue-cycle effectiveness (HFMA MAP Keys, AR-1 and AR-2). A large A/R balance is not automatically bad — payment follows care, so every practice carries receivables. What matters is how much of the money is becoming old.
| Bucket | Status |
|---|---|
| 0–30 days | Current |
| 31–60 days | Watch |
| 61–90 days | Monitor |
| 91–120 days | Act |
| 120+ days | Escalate |
How to calculate your A/R over 90 days
Add the balances in the 91–120 and over-120 buckets, divide by total billed A/R, and multiply by 100.
| Line | Example |
|---|---|
| Total billed A/R | $500,000 |
| 91–120 day A/R | $35,000 |
| Over 120 day A/R | $40,000 |
| Total over 90 days | $75,000 |
| A/R over 90 days | 15% |
What is a good A/R over 90 benchmark? Is 10% the magic number?
No single percentage determines whether every practice in every specialty has a healthy revenue cycle; specialty, payer mix, patient responsibility, claim complexity and specialized billing arrangements all change what normal looks like. As context: across AMS Solutions’ active client book, less than 10% of total A/R is over 90 days, and our 2026 Medical Billing Benchmark Report cites an industry reference of approximately 13.5%. Days in A/R of 30–40 is the commonly cited companion KPI. The practical review thresholds we use:
| A/R over 90 days | How to read it |
|---|---|
| Under 10% | Generally a strong position, assuming balances are accurate and actively managed. |
| 10–15% | Worth watching closely. Look at trend, payer concentration and what is driving the aging. |
| 15–20% | Meaningful aged A/R is accumulating. Leadership should understand exactly why. |
| Over 20% | A deeper review is warranted. Problems may involve denials, follow-up, credentialing, patient A/R or claim submission. |
These are practical review thresholds, not universal industry standards.
The trend matters more than the snapshot
Consider two practices. Practice A has 12% of A/R over 90 days, down from 19% six months ago. Practice B has 9%, up from 5%. Practice B still has the lower number, but its trend is more concerning. Ask: what was our A/R over 90 last month, three months ago, six months ago, and what is causing the movement? A healthy revenue cycle produces explanations, not just numbers. (For the full step-by-step on a rising trend, see Why does my practice A/R keep climbing?)
Not all old A/R is the same
A dollar over 90 days might be a claim under appeal, a payer requesting medical records, a credentialing problem, a patient balance, an authorization denial, an underpayment, a posting issue, or a claim nobody meaningfully followed up on. Those do not carry the same risk. “How much A/R do we have over 90 days?” is only the beginning; the next question is “What is in it?”
Break it down by payer
Your total aging percentage may hide a payer-specific problem. If $55,000 of a $90,000 aged balance sits with one commercial payer, you have a much more useful problem to investigate. HFMA includes aged A/R by payer group among its MAP Keys for exactly this reason.
Look at dollars, not only percentages
Ten percent of $100,000 is $10,000. Ten percent of $2 million is $200,000 — same percentage, very different exposure. Review both, and give large-dollar accounts individual attention even when the overall percentage looks acceptable.
Nine reasons medical A/R gets old
Old A/R usually develops for a reason, and understanding it is far more useful than telling the billing team to “work the A/R harder.”
- Claims were submitted late. Unclosed encounters, missing charges, coding backlogs, documentation delays and held claims create aging before the payer ever sees the claim.
- Claims are getting rejected. A rejected claim has not entered payer adjudication. Clearinghouse edits, demographics, insurance data, payer configuration or provider information can let claims age quietly while everyone assumes they were billed.
- Denials are not being resolved. Authorization, eligibility, coding, medical-necessity, credentialing, timely-filing and coordination-of-benefits denials all push balances into older buckets. The question is whether they are resolved fast enough.
- The same denial keeps happening. Overturning the same preventable denial every month is activity, not improvement. Strong A/R management asks why it recurs and closes the loop with the practice.
- Credentialing or enrollment is holding claims. Missing reassignment, an unenrolled location, incorrect payer linkage, or a provider seeing patients before enrollment is complete can leave clean claims unpaid for months. See credentialing and enrollment.
- Nobody is meaningfully following up. Effective follow-up may need a payer call, records, an appeal, corrected information, escalation or enrollment research. Clicking “check claim status” every few weeks is not a strategy.
- Payments are not being posted correctly. Unposted ERAs, delayed paper EOBs, unapplied payments, incorrect secondary balances and missing adjustments make A/R look older than it is.
- Patient balances are aging. Statement frequency, payment options, payment plans, returned mail and incorrect insurance-to-patient transfers all increase aged patient responsibility. Know how much old A/R is insurance versus patient.
- The balance may no longer be collectible. Missed filing or appeal deadlines, missing authorization, inadequate documentation, contract limits and true patient bad debt can make balances impossible to recover. Accurate RCM includes deciding when a balance is collectible — and understanding why it is not.
The “we’re working it” test
Ask your billing company about your A/R over 90 days. If the answer is “we’re working it,” ask another question.
| Question | Why it matters |
|---|---|
| What are the five largest balances? | Large-dollar exposure should be visible and actively owned. |
| Which payers account for the most aged A/R? | Concentration reveals payer-specific problems. |
| What are the biggest causes? | Diagnosis is more useful than generic follow-up. |
| What action was taken? | You want progress, not repetitive notes. |
| What happens next? | Every meaningful balance should have a next step. |
Look at touches, but do not worship them: four notes that all say “portal checked, still pending” are activity, not progress. Pay particular attention to the over-120-day bucket, where deadlines expire, documentation gets harder to retrieve and write-off likelihood rises — do not let it become the place where difficult claims go to die. And every meaningful balance should have an owner: the most dangerous A/R is often not the oldest balance but the balance nobody owns.
What your monthly A/R review should include
| Metric | What to ask |
|---|---|
| Total A/R | How much money is outstanding? |
| Days in A/R | How quickly are receivables converting to cash? |
| A/R over 90 days | What percentage of billed receivables has aged beyond 90 days? |
| A/R over 120 days | How much is in the highest-risk bucket? |
| A/R by payer | Which insurers are creating the aging? |
| Patient vs. insurance A/R | Who actually owes the money? |
| Top aged balances | Which accounts create the greatest exposure? |
| Denial trends | What is feeding future aged A/R? |
| A/R trend | Are these metrics improving or worsening? |
The five-question A/R test: What percentage of our A/R is over 90 days? Over 120? Which five payers account for the most aged A/R? What are the three biggest reasons those balances remain unpaid? What are we doing to reduce the number next month? A report tells you what happened; a revenue-cycle strategy tells you what happens next.
Run your own 15-minute A/R health check
From your aging report, write down total billed A/R and the balance in each bucket (0–30, 31–60, 61–90, 91–120, over 120); total the two oldest buckets and compute the percentage over 90. Then list the top five payers by aged A/R, the three biggest causes, and the three actions you need to take. Red flags to investigate: A/R over 90 or 120 steadily increasing; nobody can identify payer concentrations; the same denials recur; large balances have many notes but little movement; payments sit unapplied; or leadership keeps discovering old claims nobody owns.
What should happen next
If your A/R over 90 is higher than expected, do not start by demanding everyone work harder. Diagnose first: is the aging coming from claim submission, rejections, denials, payer processing, credentialing, payment posting, patient balances, follow-up, internal workflows or genuinely uncollectible balances? Old A/R is a lagging indicator — today’s 120-day balance was created months ago by a claim that went out wrong, a missing authorization, an unenrolled provider or a denial that sat untouched. Run recovery (work the money that is already old — our old A/R recovery service does this as a standalone engagement) and prevention (stop today’s claims from becoming tomorrow’s old A/R) at the same time.
Having receivables over 90 days does not mean your billing operation is failing. What matters is whether the practice understands how much is aging, why, who owns it, whether it is collectible, what is being done, and whether the trend is improving. If you cannot answer those questions, the most important problem may not be the percentage — it may be the lack of visibility.
Want to know what is actually sitting in your A/R? AMS Solutions will review your current aging, recent collections and billing performance to identify where receivables are accumulating. Request a no-obligation A/R analysis or call (866) 488-6308. Physician-founded in 1992, Dallas-headquartered, in-house global team, US-led; revenue cycle management, credentialing and A/R recovery under one roof.
FAQs
What percentage of A/R over 90 days is acceptable for a medical practice?
Under 10% is generally strong; 10–15% deserves close watching; 15–20% means aged A/R is accumulating; over 20% warrants a deeper review. AMS’s active clients run under 10%, and AMS’s 2026 benchmark report cites an industry reference of about 13.5%. Specialty and payer mix shift what is normal.
How do I calculate A/R over 90 days?
Add the 91–120 and over-120-day buckets from your aging report, divide by total billed A/R, and multiply by 100. For example, $75,000 aged over 90 on $500,000 total A/R is 15%.
Is A/R over 90 days more important than days in A/R?
They answer different questions. Days in A/R shows how fast receivables convert to cash overall; A/R over 90 shows how much of the inventory has gone stale. Review both, plus the trend, the payer breakdown and the dollar amounts.
Why would A/R over 90 days rise when collections are fine?
Collections can continue from earlier claims while a new problem builds — rejections nobody is monitoring, a denial that recurs every month, a provider whose enrollment lapsed, or payments that arrived but were never posted. The aging report lags the cause by months.
What should I ask my billing company about aged A/R?
The five largest balances, the payers with the most aged A/R, the biggest causes, the specific action taken on each large balance, and what happens next. “We’re working it” is not an answer.
