Days in A/R: compute it, benchmark it, move it

What the number actually measures

Days in A/R answers one question: if every appointment stopped tomorrow, how many days' worth of your current billing rate is still sitting in unpaid claims and patient balances? The formula divides your total outstanding receivables by your average daily charges — total charges over a trailing period (commonly the last 90 days) divided by the number of days in that period. A smaller number means cash catches up to your work faster.

Days in A/R = Total A/R ÷ (Total charges over trailing period ÷ days in period)

The trailing period is a modeling choice, not a rule. Ninety days smooths out one slow month without hiding a real multi-month drift the way a 30-day window can. Once you pick a window, keep it fixed — changing it to make the number look better defeats its only purpose, which is showing you a trend you can trust month over month.

Calculating it from your own numbers

Pull two figures from your practice management system's reports: current total accounts receivable — every unpaid claim and patient balance, current or aged — and total charges billed over the trailing 90 days. Divide the charge total by 90 to get average daily charges, then divide total A/R by that daily figure. The result is denominated in days: literally how many days of billing your current receivables represent.

Example: total A/R of $85,000 ÷ ($180,000 in trailing-90-day charges ÷ 90 days = $2,000/day) = 42.5 days in A/R.

A new practice should start tracking this from the first-90-days dashboard rather than waiting until enough history piles up to make the number feel meaningful. The earlier you establish a baseline, the sooner a bad trend stands out against it instead of blending into normal early-practice noise.

What's healthy for a solo practice — and why there's no single number

There is no universal target that fits every solo practice, because the metric is driven as much by payer mix as by billing quality. A caseload paid mostly through two Medicaid managed-care plans and workers' comp will run structurally higher than one paid mostly through commercial PPOs with fast electronic remittance — not because the second practice bills better, but because its payers move faster by contract and by system design.

Published benchmarks for this metric exist and are worth checking once a year, but only after you adjust for your own payer mix — your overhead at micro scale looks nothing like a multi-provider group's, and borrowing that group's number as your target is the fast way to chase a level that was never realistic for your caseload. The honest comparison is your own trailing trend: is this month's number higher or lower than the same month last year, and is the gap explained by a payer or a process you can actually fix.

Reading the aging buckets underneath the headline number

A single days-in-A/R figure can hide a real problem: a healthy-looking average sitting on top of a small pile of claims about to become permanent losses. Break the same total A/R into 0–30, 31–60, 61–90, and 90+ day buckets before deciding the headline number is fine — each bucket calls for a different action, and the oldest bucket is the one with a deadline attached.

Exact timely-filing and appeal windows are set payer by payer in your own contracts, so treat the 90-day mark as a trigger to check that specific deadline rather than a universal cutoff.

What drives the number up — and the fixes that bring it down

Four things reliably push days in A/R higher: unverified eligibility that produces denials after the visit, claims that go out with errors and bounce back for correction, denials that sit un-worked because no one owns the worklist, and patient balances that go uncollected at time of service. Each has a specific fix, and none of them is "see more patients" — a full schedule answers a different question, how full is my schedule really, not whether the money for the work already done has arrived.

• Verify eligibility and benefits before the visit rather than after the denial.
• Submit clean claims the first time — the fewer touches a claim needs, the faster it moves.
• Work denials same-week, oldest-aging-bucket first, since a denial that sits also risks a payer's appeal deadline.
• Collect patient balances at time of service or through card-on-file rather than a mailed statement, the slowest dollar in the practice to collect.

If the aging worklist is chronically stale because no one is dedicated to working it, that is one of the clearer signals behind the first hire decision — a part-time biller, not another clinician.

Why this number feeds your tax and retirement math

Once days in A/R is stable and trending down rather than up, it stops being just a collections metric and starts feeding two decisions that are otherwise guesswork: whether your profit is stable enough to justify an S-corporation election, and how much you can safely fund into a retirement plan before the following tax season.

An LLC's default federal tax treatment is disregarded-entity or partnership status, with a corporate or S-corporation election layered on top as a separate choice 1Ref 1Internal Revenue Service (2026).Limited liability company (LLC).Supports that an S-corp election is a tax-classification choice layered on default LLC treatment, distinct from the state-law entity.. That election is made on Form 2553, generally due within two months and fifteen days of the start of the tax year it's meant to cover 2Ref 2Internal Revenue Service (2026).About Form 2553, Election by a Small Business Corporation.Supports the Form 2553 filing deadline for the S-election, timed off a stable and predictable profit picture. — a date you calendar with confidence only once your receivables behave predictably enough to know what this year's profit will actually be. The same logic runs through retirement funding: a SEP-IRA lets you contribute up to 25% of compensation within the annual limit 3Ref 3Internal Revenue Service (2026).Simplified Employee Pension plan (SEP).Supports that SEP-IRA contribution capacity is based on actual collected compensation, not billed charges., and "compensation" means what you actually collected, not what you billed — exactly the gap this metric measures. If the balance you're finally chasing down goes to a part-time biller or collections service you bring on to work the worklist, paying that person more than $600 in the year means issuing them a 1099-NEC 4Ref 4Internal Revenue Service (2026).About Form 1099-NEC, Nonemployee Compensation.Supports the 1099-NEC obligation triggered by paying a contract biller or collections service over $600 in a year..

When the clock doesn't apply: value-based and capitated arrangements

Not every dollar you're owed sits on this clock. Value-based and capitated arrangements — the alternative payment models the CMS Innovation Center has spent over a decade testing 5Ref 5Centers for Medicare & Medicaid Services (2026).CMS Innovation Center.Supports that value-based and capitated arrangements pay on a schedule distinct from fee-for-service claims adjudication. — pay on a schedule tied to attribution or care events rather than individual claim adjudication, so a practice with meaningful value-based volume should track fee-for-service days in A/R separately from that revenue rather than blending them into one misleading average.

This number belongs on the solo dashboard next to net collection rate and no-show cost, reviewed monthly as a set rather than chased daily in isolation. Watched alone and daily, it produces noise; watched monthly alongside the other four or five numbers that describe the same practice, it produces a picture you can act on.