Days in A/Rtotal A/R÷average daily charges
Average daily chargescharges over a period, net of credits÷days in the period
One professional body, not two: AAFP calls 30–40 days preferable and below 50 the minimum. The page usually quoted as HFMA agreeing is sponsored content, and its range is attached to a different denominator.
There is a free A/R days calculator on this site if you just want the number. This guide covers exactly what days in A/R measures, how to calculate it (and the gross-vs-net trap that makes two practices disagree), what a good number really is, the separate aging metric everyone conflates with it, and the levers that actually bring it down.
What days in A/R actually measures
Accounts receivable is money you've earned but haven't collected — claims out with payers, balances out with patients. Days in A/R converts that pile into a single, comparable number: if you stopped billing today, how many days of charges are still sitting unpaid? Lower is faster cash; a rising number is billing falling behind, weeks before you feel it in the bank.
The one subtlety that trips people up is the denominator. AAFP defines average daily charges on your charges net of credits, over a period you choose — "three months, six months, 12 months." HFMA's hospital-oriented version instead divides net A/R by average daily net revenue. Same idea, different denominator — which is precisely why two practices "measuring the same thing" land on different numbers. Pick one definition, write it down, and use it consistently; the comparison that matters is against your own prior quarters, not someone else's spreadsheet.
What's a good days in A/R?
Here the guidance is unusually consistent. AAFP puts it plainly: days in A/R "should stay below 50 days at minimum; however, 30 to 40 days is preferable." A second page, often quoted as HFMA guidance, says the same: "Ideally, days in A/R should range between 30 to 40." Two things about it. It is marked sponsored content, paid for by a revenue-cycle outsourcing vendor, and it points readers back to the AAFP. And the 30 to 40 there is attached to plain days in A/R on a gross-charges denominator, not to net days in A/R, which the same page defines separately and gives no target for. HFMA's own MAP Keys define net days in A/R and publish no number at all. It is a target a professional body publishes, not a measured median, and worth treating as such.
Two honesty flags, because the vendor blogs skip them. First, 30–40 is a guideline, not a study — it's a professional rule of thumb, not a measured average, so don't quote it as "the industry average." Second, the real numbers are a moving target: across a dataset of 2,100+ hospitals and roughly 300,000 physicians, measured A/R days grew 5.2% year over year in 2024 (Kodiak Solutions), alongside rising denials. And the tidy "MGMA median = X days" figures circulating online aren't verifiable — MGMA's absolute medians live behind the paid DataDive, though its Data Mine write-up publishes the better-performer distribution free: over 70% of A/R under 30 days and 8.1% past 120, from 2020 data on multispecialty groups. Treat 30–40 as your target and your own trend as the verdict.
Days in A/R vs. "A/R over 90 days" — not the same number
These get used interchangeably, and they're different metrics. Days in A/R is the average speed of your whole receivables pile. A/R over 90 days is an aging metric — the share of what you're owed that's been sitting past 90 days, and it's the one that predicts write-offs, because collectibility drops the longer a balance ages.
The healthy threshold depends on who you ask: AAFP's long-standing rule is under 15% of A/R over 90 days; HFMA sets a tighter under 10%. Either way, the top performers barely carry aged balances at all — MGMA's "better performers" keep over 70% of their A/R under 30 days and just 8.1% past 120 days. Watch both numbers: a healthy average can still hide an ugly tail of old claims nobody's working.
Why days in A/R is worth watching
It's an early-warning gauge, and it doesn't drift alone. Days in A/R sits at the end of a chain that starts with clean claims and denials — it's the outcome of your revenue cycle, not an isolated stat. When it climbs, look upstream: initial claim denials rose to 11.81% in 2024, and A/R days rose right alongside them (Kodiak). A denial you don't rework fast becomes an aged balance, which becomes a write-off.
The other pressure is coming from patients. As high-deductible plans spread, more of every bill lands on the patient — the average single-coverage deductible hit $1,787 in 2024 (KFF), and patient balances are the hardest kind to collect: providers recovered just 34.46% of what insured patients owed in 2024, down from 37.58% the year before (Kodiak). That uncollected patient portion doesn't vanish — it ages inside your A/R and drags the number up a day at a time. Days in A/R is where all of that becomes visible.
How to cut your days in A/R
Five levers, and none of them needs new software. They change what happens to a claim after it leaves your office.
Work denials fast — set a clock
HFMA's operational target is to resolve 85% of denials within 30 days. Every day a denied claim sits is a day added to A/R; a worklist with a deadline is the single biggest lever, especially as denial rates climb.
Automate follow-up, not just submission
"Submit claims electronically" is stale advice — that's already ~98% done (CAQH 2024). The gains left are downstream: electronic claim-status checking and remittance posting are far less automated (claim-status inquiry sits around 80% for medical plans and just 28% for dental). Automating the chase, not the send, is where A/R days come down.
Collect the patient portion up front
With deductibles rising, a balance left to chase after the visit is the one that ages out. Estimating and collecting at the point of care — or setting card-on-file plans — is the cheapest recovery there is, and it keeps patient responsibility from silently inflating A/R.
Keep the aged buckets small
Track A/R by age (0–30 / 31–60 / 61–90 / 90+) and work the oldest first. The goal is the top-performer shape: most of your A/R under 30 days, very little past 90. Aging is collectibility draining away in slow motion.
Raise your clean-claim rate
The fewer claims that bounce on first pass, the less ends up in the follow-up pile at all. Front-end accuracy — eligibility, coding, prior auth — is the quietest way to pull days in A/R down, because the fastest denial to work is the one that never happens.
You can't shorten what you don't watch
Most practices can quote their revenue but not how many days of it are sitting unpaid right now — or which payer and which age bucket are dragging the number up. Put days in A/R on the dashboard next to your aging buckets, tracked against your own prior quarters, and a billing slowdown stops being a cash-flow surprise and becomes a worklist. It's one of the 12 KPIs every practice should track, and it's inseparable from the net collection rate that decides how much of that A/R you ultimately keep. Collection rate tells you whether you get paid; this tells you when — which is why both sit in the weekly five-number review. It sits in the middle of the revenue cycle, between the claim going out and the cash arriving — one of the six KPIs worth watching there.
Frequently asked questions
Days in A/R (days in accounts receivable) is the average number of days it takes a practice to collect payment after a service is billed. It equals total accounts receivable divided by average daily charges.
Days in A/R = total A/R ÷ average daily charges, where average daily charges = total charges over a period (net of credits) ÷ the number of days in that period. AAFP names three, six or twelve months as options and does not favour one.
30 to 40 days is the preferred range and under 50 days is the minimum (the AAFP). It's a professional guideline rather than a measured average, and real numbers vary by specialty and payer — so track your own trend.
Guidance ranges from under 15%, which comes from an AAFP article published in 1999, to under 10% on a more recent page of total A/R sitting over 90 days old. The older a balance gets, the less likely it is to be collected.
WRITTEN BY
Olha · clinic data analyst
I build the reporting our managers open every morning at a multi-branch medical clinic — and package it so other practices don't have to start from scratch.
The 30–40 day and over-90-day figures are the AAFP professional guidance rather than a single study; measured-trend figures are from Kodiak Solutions' 2024 dataset, deductibles from KFF, and electronic-transaction figures per the 2024 CAQH Index. Lucid Vitals is not affiliated with Microsoft.