Your aging report is the most important financial document in your practice. It tells you exactly where your money is, how long it's been sitting there, and whether anyone is doing anything about it. And most practice managers either don't look at it, look at it wrong, or look at it and don't know what the numbers are telling them.
This is a practical guide to reading your aging report the way a billing expert reads it. Not the theory. The actual numbers, what they mean, and the specific red flags that tell you your practice is losing money.
An aging report (sometimes called an AR aging report or accounts receivable aging report) is a snapshot of every dollar your practice has billed but hasn't collected yet. It groups those outstanding balances by how old they are.
Most practice management systems break the aging into standard buckets:
| Aging Bucket | What It Means | Healthy Benchmark |
|---|---|---|
| 0-30 days | Claims submitted in the last month. These are in the normal processing window. | 50-65% of total AR |
| 31-60 days | Claims that should have been paid but haven't been. Payer follow-up should be happening. | 15-25% of total AR |
| 61-90 days | Claims that are overdue. Active follow-up is critical. Recovery probability starts dropping. | 5-10% of total AR |
| 91-120 days | Claims approaching the danger zone. Many payers' appeal windows close at 90 days. Recovery drops significantly. | Under 5% of total AR |
| 120+ days | Claims that are likely unrecoverable without aggressive intervention. Many have passed timely filing deadlines. | Under 5% of total AR |
The distribution of your AR across these buckets tells you more about your billing health than any single metric. A practice with 70% of AR in the 0-30 bucket and 3% in the 120+ bucket has a healthy revenue cycle. A practice with 40% in 0-30 and 25% in 120+ is hemorrhaging revenue.
This is the total dollar amount outstanding across all buckets. On its own, this number is meaningless. A practice billing $500K/month with $600K in total AR is healthy. A practice billing $100K/month with $600K in total AR is in crisis.
The metric that matters is total AR as a ratio of monthly charges. Divide your total AR by your average monthly billed charges. The result tells you how many months of revenue are sitting uncollected.
Benchmark: Total AR should equal 1.0-1.5x your average monthly charges. If you bill $200K/month, your total AR should be $200K-$300K. If it's $500K+, your billing team isn't collecting fast enough.
This is the average number of days it takes for a claim to get paid from the date of service. Your PM system calculates this automatically.
Under 30 days: Excellent. Your claims are getting paid quickly.
30-40 days: Acceptable. Room for improvement but not alarming.
40-50 days: Problem. Claims are sitting at payers too long. Follow-up is insufficient.
50+ days: Crisis. Your billing operation has a systemic issue with submission timing, follow-up, or both.
This is the single most important number on your aging report. It tells you what percentage of your outstanding revenue is old enough that recovery becomes difficult and expensive.
Red flag: If more than 15% of your total AR is in the 90+ day bucket, your practice is writing off revenue that should have been collected. Industry data shows recovery rates drop by 50% after 90 days and by 80% after 120 days. Every dollar in the 90+ bucket costs progressively more to recover.
Healthy: Under 10% of total AR over 90 days.
Concerning: 10-20% over 90 days. Investigate immediately.
Critical: Over 20% over 90 days. Your billing operation needs immediate intervention.
Money in the 120+ bucket is almost certainly lost. Most payer appeal windows have closed. The cost of working these claims often exceeds the expected recovery. The only question is how much money is sitting there and whether it's growing or shrinking.
If your 120+ bucket is growing month over month, claims are aging through the system without being worked. They're entering at 0-30, nobody touches them, and they slide through 31-60, 61-90, 91-120, and into 120+ where they die.
That's not a denial problem. That's a follow-up problem. And it means your billing team (in-house or outsourced) is submitting claims but not managing the revenue cycle after submission.
Your write-off rate is the percentage of billed charges that are ultimately written off as uncollectable. This number doesn't appear on the aging report directly, but you can calculate it from your monthly reports.
Write-off rate = Total write-offs / Total charges billed
Under 3%: Healthy. Normal contractual and bad debt write-offs.
3-5%: Elevated. Some claims are being abandoned that could be recovered.
Over 5%: You're losing real money. Claims are being written off without proper follow-up or appeal.
Important distinction: Contractual adjustments (the difference between your billed charge and the payer's allowed amount) are NOT write-offs. They're expected reductions per your payer contracts. Only count actual bad debt, abandoned claims, and unrecoverable denials as write-offs.
Pull your aging report right now. Here's what to look at, in order:
What percentage of your total AR is in each bucket? Write down the percentages and compare to the benchmarks above. If your 0-30 bucket is less than 50% of total AR, your claims are not getting paid fast enough. If your 90+ bucket is above 15%, money is dying in the system.
Filter your aging report to show only claims over 90 days, grouped by payer. Is one payer responsible for a disproportionate share of old AR? If 60% of your 90+ AR is from one insurance company, you have a payer-specific problem: either a credentialing issue, a recurring denial pattern, or claims that were never followed up after initial denial.
Scenario: A 3-provider family practice pulls their aging report. Total AR is $340K against $180K/month in charges (1.9x ratio, slightly elevated). The 90+ bucket contains $78K (23% of total AR, well above the 10% benchmark).
Filtering the 90+ bucket by payer reveals: Aetna has $42K of the $78K. The practice checks and discovers a credentialing issue: one provider's enrollment with Aetna lapsed 4 months ago and all claims for that provider have been denying with CO-185. Nobody noticed because the denials were sitting unworked in the queue.
Recovery: $42K in claims, retroactive credentialing application submitted, $38K recovered within 60 days.
A single aging report is a snapshot. You need to compare this month's report to last month's and the month before. Is the 90+ bucket growing, shrinking, or stable?
Growing 90+ bucket: Active problem. Claims are aging through without being worked. This won't fix itself.
Stable 90+ bucket: Chronic problem. Claims are being worked at the same rate they're entering. You're treading water but not improving.
Shrinking 90+ bucket: Good sign. Your billing team is working through old AR and preventing new claims from aging past 90 days.
Your effective collection rate tells you what percentage of your allowed charges (not billed charges) you're actually collecting. This is different from your gross collection rate, which compares collections to billed charges and is inflated by the gap between your fee schedule and payer allowances.
Effective collection rate = Total payments / Total allowed amounts
A healthy effective collection rate is 95% or above. If yours is below 90%, significant revenue is leaking between what payers owe you and what you're actually depositing.
Your aging report shows you where the money is stuck. Your denial codes tell you why. Filter your denied claims by denial code and sort by dollar amount. Your top 3-5 denial codes by dollar value are your biggest revenue recovery opportunities.
Common patterns: CO-185 (credentialing) clusters around one provider. CO-21 (missing information) clusters around one payer. CO-49 (invalid procedure code) spikes in January when new CPT codes take effect. Each pattern has a specific fix. If the same denial codes appear month after month, your billing team isn't fixing root causes.
| Metric | Healthy Practice | Broken Practice |
|---|---|---|
| AR distribution (0-30) | 60% of total AR | 35% of total AR |
| AR distribution (90+) | 8% of total AR | 28% of total AR |
| Days in AR | 32 days | 54 days |
| AR to monthly charges ratio | 1.2x | 2.5x |
| Write-off rate | 2.1% | 7.4% |
| Effective collection rate | 97% | 84% |
| Clean claim rate | 96% | 74% |
If your numbers look more like the "broken" column than the "healthy" column, the revenue gap is real and measurable. A practice billing $200K/month with a 97% vs 84% effective collection rate is collecting $26K less per month. That's $312K per year in revenue that was earned, billed, and lost somewhere in the billing process.
If your aging report reveals problems, the response depends on the severity.
If your 90+ AR is 10-15% and growing: Your billing team needs to prioritize old AR follow-up. Pull every claim over 90 days, sort by dollar value, and work the highest-value claims first. Set a weekly target for reducing the 90+ bucket. This is fixable with focused effort over 60-90 days.
If your 90+ AR is over 20%: This is a systemic problem that focused effort alone won't fix. Your billing operation has a workflow gap: claims are being submitted but not managed after submission. You need either dedicated denial management staff, a process overhaul, or a billing partner with a proven denial recovery system.
If your write-off rate is over 5%: Money is being abandoned. Pull your write-off report and categorize every write-off by reason. If the majority are "unable to collect" or "past filing deadline," claims are aging past their recovery window without being worked. This is the most expensive billing failure because the money was earnable and is now permanently gone.
If you can't get these numbers at all: That itself is a red flag. Your billing team (in-house or outsourced) should be producing these metrics monthly without being asked. If you have to request them and they take days to produce, the data infrastructure isn't there, which means nobody is managing the revenue cycle proactively.
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