For most outpatient practices, a good days in A/R is roughly 30 to 40 days. Under 35 days is strong performance, 35 to 50 days is workable but slipping, and anything past 50 days usually means claims are going out late, denials are not being worked, or patient balances are aging untouched.
But the headline number is only half the story. A practice can post a respectable 38 days in A/R while quietly carrying six figures in claims older than 120 days. The aging buckets are where the truth lives.
How to calculate days in A/R
The standard formula is straightforward:
Days in A/R = Total accounts receivable / Average daily charges
Average daily charges is your gross charges over a trailing period divided by the number of days in that period. Most practices use a trailing 90 days, which smooths out seasonality without going so far back that it hides a recent problem.
A worked example
A practice bills 1,350,000 dollars in gross charges over the trailing 90 days. That is 15,000 dollars in average daily charges. If total A/R on the report date is 525,000 dollars, days in A/R is 35.
Two decisions that change the answer
- Gross versus net charges. Days in A/R calculated on gross charges runs higher than the same practice measured on expected reimbursement. Pick one, document it, and never quietly switch.
- Credit balances. Leaving unapplied credits in the total artificially deflates A/R. Report them separately so they do not mask an aging problem.
The benchmark depends on your payer mix
A dermatology practice billing mostly commercial plans and a behavioral health group billing mostly Medicaid are not playing the same game. Medicaid and workers' compensation reliably run longer. High-deductible commercial plans push balance to the patient, and patient balances age far more slowly than payer balances.
| Measure | Strong | Acceptable | Needs attention |
|---|---|---|---|
| Days in A/R | Under 35 days | 35 to 50 days | Over 50 days |
| A/R over 90 days | Under 12% | 12% to 20% | Over 20% |
| A/R over 120 days | Under 8% | 8% to 12% | Over 12% |
| Clean claim rate | 95% or better | 90% to 95% | Under 90% |
| Net collection rate | 96% or better | 93% to 96% | Under 93% |
Aging buckets tell you what the average hides
Split the receivable into 0 to 30, 31 to 60, 61 to 90, 91 to 120 and 120-plus days, and split each bucket again by payer versus patient responsibility. The pattern you want is a steep pyramid: most of the balance in the newest bucket and very little past 90 days.
Two failure patterns show up constantly:
- A fat 0 to 30 bucket with a healthy total. Charges are being entered but claims are not going out. Check lag time from date of service to claim submission — it should sit at 1 to 3 days for most visit types.
- A thin recent bucket and a heavy 120-plus tail. Current work is fine, but nobody is touching old claims. That tail is usually recoverable for another few months and then it is not.
Key takeaway
Days in A/R measures speed. The aging buckets measure whether anything is being abandoned. Track both, every month, and never accept one without the other.
What actually pushes days in A/R up
In our experience onboarding practices, the causes cluster into five:
- Charge lag. Notes are not closed, so charges are not entered, so claims are not filed. This is a clinical workflow problem wearing a billing costume.
- First-pass denials. Every denial adds a full adjudication cycle. A practice at a 12% initial denial rate is structurally slower than one at 5%, no matter how good its follow-up is.
- No follow-up cadence. Claims that go unworked between day 30 and day 60 quietly become the 120-plus bucket.
- Unposted or misposted payments. Payments sitting in a lockbox or posted to the wrong encounter inflate A/R that has already been collected. Disciplined payment posting and reconciliation is the unglamorous fix.
- Patient balances with no statement cycle. If the first statement goes out 45 days after the visit, you have added 45 days to your own number.
A 90-day plan to bring the number down
Days 1 to 30 — measure and triage. Produce a clean aging report by payer and by bucket. Work the 91-to-120 bucket first, because it is the largest recoverable balance that is closest to expiring. Confirm timely-filing and appeal deadlines for every payer on the list.
Days 31 to 60 — fix the front end. Verify eligibility before every visit, close the authorization gaps, and pull charge-entry lag under three days. This is where days in A/R stops rising.
Days 61 to 90 — build the cadence. Assign every aging bucket an owner and a touch frequency. Report weekly on dollars worked, dollars collected and dollars written off, with a reason attached to every write-off.
Sustained improvement comes from doing all three at once, which is why our A/R management service pairs recovery work on the old balance with front-end fixes on the new one.
Three questions to ask your billing team this month
- What is our days in A/R, and what denominator window did you use?
- What percentage of our A/R is over 90 days, split by payer and patient?
- How many dollars did we write off last month, and what were the top three reasons?
If those answers are slow to arrive or vary depending on who you ask, the reporting is the problem to solve first. See how we report on revenue cycle performance, or book a review of your A/R and we will walk the aging report with you.
