How to Reduce Days in AR Without Writing Off Revenue

To reduce days in AR without losing money, first calculate it the same way every month, then split the aging report by payer and by the reason each claim is stuck. Fix the causes that release cash fastest: unposted payments, denials you can correct, and underpaid lines. Never shrink accounts receivable by writing off claims you could still collect.

How do you calculate days in AR correctly?

Days in accounts receivable (AR) is the number of days of revenue sitting unpaid. The Healthcare Financial Management Association defines it in its HFMA MAP Keys definitions as net AR divided by average daily net patient service revenue, with net AR taken from the balance sheet.

Each half of that fraction has rules that change the answer. Net AR, in the HFMA definition, is the patient receivable net of credit balances, allowances for uncollectible accounts, charity discounts and contractual allowances. In plain terms, it is what you expect to collect, not what you charged. The denominator is net patient service revenue, which HFMA defines as gross patient service revenue minus contractual allowances, the charity care provision and the provision for doubtful accounts.

The time window matters as much as the formula. HFMA uses a three-month daily average: the revenue for the three months ending with the reporting month, divided by the number of calendar days in those months. Its own example uses April, May and June, which gives 91 days. A practice that divides by 30 one month and by 365 days of annual revenue the next will see the number move for reasons that have nothing to do with collections.

Three mistakes distort the calculation more than any other:

• Gross AR over net revenue. Some practice management systems report AR at full charges. Dividing gross charges outstanding by net revenue inflates the result, sometimes by a wide margin, because the contractual allowance is still sitting in the numerator.
• Credit balances netted silently. A large patient refund owed, or a payer overpayment, lowers total AR and makes the number look better than the debit balances justify. Report credit balances on their own line.
• Changing the source. HFMA says that unless the processing system changes, the same sources must be used each month. Switch reports and you break the trend.

Pick one report for the numerator, one for the denominator and one window, write them down, and keep them. How this figure sits beside the other revenue cycle measures is covered in the guide to days in AR and the other dashboard formulas, so this post stays on lowering it.

Splitting AR aging by payer and cause

An AR aging report sorts open balances into buckets by how long they have been outstanding. HFMA's aged AR keys use 0 to 30, 31 to 60, 61 to 90, 91 to 120 and over 120 days, aged from the date of service for physician practices. Splitting those buckets by payer, then by cause, shows where money is actually stuck.

The payer split comes first because payers behave differently. HFMA publishes a separate key for aged AR by payer group, since one slow plan can hide inside a healthy total. The cause split comes second, and it needs the denial and remark codes from each remittance, plus your own notes on claims with no response at all.

A worked aging example

The table below is a fictional practice. Every name and amount is made up for the example. Its net patient service revenue for July, August and September was $1,380,000 across 92 days, so average daily revenue is $15,000.

Days in AR before any fix: $780,000 divided by $15,000 is 52.0 days.

The payer split already points somewhere. The example Medicare Advantage plan holds $90,000 over 60 days, more than any other payer, even though its total is smaller than the commercial plan's. Working the claims in those buckets turned up three causes in this fictional practice:

1. Unposted payments. $45,000 of paper EOBs for Medicare and the commercial plan had been deposited but not yet posted, so those claims still showed as open.
2. Authorization denials. $60,000 at the Medicare Advantage plan carried claim adjustment reason code 197, which the X12 claim adjustment reason code list describes as "Precertification/authorization/notification/pre-treatment absent."
3. Underpaid lines. $25,000 at the commercial plan had been paid below the contracted rate.

The next section shows what fixing those three causes does to the number.

Which fixes reduce days in AR fastest?

The fixes that reduce days in AR fastest are the ones where the money already exists or the payer only needs a correction: posting payments already received, correcting and resubmitting claims denied for fixable reasons, and asking payers to reprocess underpaid lines. Contract renegotiation and new staff help later, but they take months to show.

Ranking the causes by speed gives a working order:

• Post what you have been paid. An unposted payment is cash in the bank that still counts as AR. Clearing a posting backlog lowers the number the day the work is done. Paper EOBs are the usual backlog, and the EOBs and remittances category explains how posting from them works line by line.
• Correct fixable denials. Denials for missing information, a wrong member ID or a missing authorization number can often be corrected and resubmitted within days. The denial code tells you which kind you have.
• Chase claims with no response. A claim with no payment and no denial after 30 days may never have reached the payer. A status check is cheaper than waiting another month.
• Watch the filing limit. Medicare's rule in 42 CFR 424.44 on time limits for filing claims requires a claim to be filed no later than one calendar year after the date of service. Commercial plans set their own limits in the contract. A claim that misses its limit usually cannot be collected at all, so aging claims near a deadline jump the queue.
• Recover underpayments. These take longer because the payer must agree, but they are real money that is already owed.

The worked example after three fixes

Back to the fictional practice. Over six weeks its team posted the $45,000 EOB backlog, corrected and resubmitted the authorization denials and was paid $36,000 of the $60,000, and had the commercial plan reprocess underpaid lines for $18,000 of the $25,000 variance. For the arithmetic, new charges and routine collections are held equal, and revenue is held at $15,000 a day.

The practice lowered days in AR by 6.6 days and wrote off nothing. The $24,000 of authorization denials still open and the $7,000 of disputed underpayments stay in AR, because they are still being worked. Strictly, a recovered underpayment also raises net revenue a little, which would lower the result slightly further; the example ignores that to keep the steps clear.

Whether software belongs in this work is a cost question, and the guide to building the business case for RCM automation walks through that arithmetic. For practices whose backlog is paper, Schema Care reads EOB service lines, plan payments and remark codes into fields and asks a person to confirm any value it is unsure of on the original page; the documents it reads are listed on the homepage.

Finding underpayments hidden in AR against contracted rates

An underpayment is a claim line paid below the rate in your contract with that payer. It hides in AR because the claim looks paid, and a small leftover balance often gets adjusted off as a routine contractual adjustment. Finding underpayments against contracted rates means comparing each line's allowed amount with the fee schedule you signed.

The adjustment code is the first clue. Payers usually label the gap between your charge and their allowed amount with reason code 45, which the X12 list describes as "Charge exceeds fee schedule/maximum allowable or contracted/legislated fee arrangement." That code is correct when the allowed amount matches your contract. It is the same code when the payer has loaded the wrong fee schedule, so the code alone proves nothing.

A simple check works on any remittance:

1. Load your contracted rates for each payer and procedure code into a table, with effective dates.
2. For each paid line, look up the contracted rate for that payer, code and date of service.
3. Flag every line where the allowed amount is below the contracted rate by more than a few cents.
4. Group the flagged lines by payer and code, because one wrong fee schedule entry repeats on every claim.

A fictional example: the contract sets $128.00 for an office visit code, and the remittance shows an allowed amount of $112.00 with a CO-45 adjustment. The $16.00 gap looks small. Across 400 such visits in a quarter, the example practice is short $6,400 from one payer and one code.

Two edge cases cause false alarms. Multiple procedure reductions and modifier rules can lawfully lower an allowed amount below the base rate, so check the modifier before you dispute. And a fee schedule update that the payer applied on time, but your table did not, makes correct payments look short. Keep the effective dates current.

Lowering days in AR by writing off claims

Writing off old claims lowers days in AR immediately, which is exactly why it is a tempting mistake. The number improves because collectible revenue has been removed from the books, not because cash came in. A write-off of a claim you could still win is a loss that the metric hides.

In the fictional practice above, writing off the $75,000 in the over-120 bucket instead of working it would have taken AR from $780,000 to $705,000, or 47.0 days. That looks almost as good as the 45.4 days the three fixes produced. The difference is that the fixes collected $99,000 and the write-off collected nothing.

HFMA guards against this with a separate measure. Its key for denial write-offs as a percentage of net patient service revenue tracks dollars written off as denials, net of recoveries, against average monthly net revenue. If days in AR falls while denial write-offs rise, the improvement is suspect. Report the two side by side.

Not every write-off is a mistake. A claim past the payer's filing limit, a balance below the cost of collecting it, or a debt your policy sends to an agency are legitimate reasons. The test is whether a write-off follows a written policy and a documented reason code, or whether it follows a month-end target. An AR goal without a write-off rule can be reached the cheap way.

A few habits keep the number honest:

• Require a reason code and an approver for every write-off above a set amount.
• Review write-offs by payer each month, next to the denials that caused them.
• Treat a sudden drop in the over-120 bucket as a question, not a win, until you know whether cash or adjustments caused it.

A falling days-in-AR figure is worth celebrating only when the cash report rises with it.