Most denial reports show one rate and a pile of A/R. Neither tells a biller what to do on Monday. The numbers that change behavior are narrower: how many claims denied on the first pass, how many dollars were written off, how often the practice appealed, how often it won, how long the appeal took, and how much denial A/R sits inside a filing window that is closing. This is how to define each one and which direction means the work is improving.
What this covers
- HFMA defines the initial denial rate two ways, by claim volume and by claim dollars, and the two versions can point in opposite directions.
- Denial write-off rate is HFMA MAP Key AR-6: net dollars written off as denials divided by average monthly net patient service revenue.
- Appeal rate and overturn rate only work as a pair. A high overturn rate on a low appeal rate means denials were abandoned, not won.
- Original Medicare allows 120 days from receipt of the initial determination to file a redetermination. Medicare Advantage and Medicaid managed care allow 60.
- Age denial A/R from the date of service, because the filing clock runs from the visit, not from the denial.
An overturn rate without an appeal rate measures how well you argue the cases you chose to fight.The denials nobody appealed are the ones that reach the write-off column.
The definitions below come from two places. HFMA’s Claim Integrity Task Force set out a standard set of claim integrity KPIs, and HFMA’s MAP Keys define the remittance denial rate (AR-5) and denial write-offs as a percentage of net patient service revenue (AR-6). The filing and decision windows come from the regulations that govern Medicare fee-for-service appeals, Medicare Advantage reconsiderations, Medicaid managed care appeals and ERISA group health plans.
Two cautions before the numbers. First, HFMA publishes the formula, the inclusions and the exclusions, and it does not publish a target value for any of these metrics, so treat every quoted benchmark as a convention and set your own floor from your own best quarter. Second, a rate without a payer split hides the payer causing it.
The six numbers, and what each one answers
HFMA’s task force named five claim integrity KPIs, and one of them is really two measures. The set below adds the appeal rate and a denial aging view, because those are the ones a billing team can move inside a month.
| Metric | How it is built | Direction that means the fix worked |
|---|---|---|
| Initial denial rate, volume | First-denial claims divided by claims submitted | Down, holding the claim mix steady |
| Initial denial rate, dollars | First-denial gross charges divided by submitted gross charges | Down, and faster than the volume version when the fix targets high-dollar services |
| Denial write-off rate (AR-6) | Net dollars written off as denials divided by average monthly net patient service revenue | Down, judged after appeal windows close |
| Appeal rate | Appeals filed divided by denials received | Up, until the overturn rate starts to fall |
| Overturn rate | Initial denials overturned and paid divided by initial denials paid and adjusted | Up in the categories you choose to fight |
| Days to appeal | Days from the initial denial remittance to the appeal submission date | Down |
| Days to resolution | Days from the initial denial remittance to a zero balance | Down |
MAP Key AR-5, the remittance denial rate, divides claims denied by claims remitted and includes appeal denials. The task force’s initial denial rate counts only the first denial on a claim. Mix the two and the rate moves for reasons nobody can explain, so label the column and keep the definition fixed month to month.
Initial denial rate: measure volume and dollars separately
The task force defines the initial denial rate twice. As a percentage of claim volume it is total initial denial claims divided by total claims submitted. As a percentage of claim dollars it is total initial denial claims gross charges divided by total claims submitted gross charges. Both use the average of the three months before the reporting month as the denominator, so a quiet month does not fake a better rate. Denial claims means the first denial on the claim. If a claim denies twice, only the first chronological denial counts, and rebills come out of both versions.
The two versions answer different questions. A claim count treats one 15 minute session of 97153 and a full diagnostic evaluation as one denial each. The dollar version weights each denial by what it was worth. In ABA and behavioral health billing, where treatment codes bill in 15 minute units, a units or authorization failure denies a block of sessions at once and pushes the dollar rate far above the volume rate. Track both, and read the gap.
| Measure | Volume basis | Dollar basis |
|---|---|---|
| Denominator | 1,000 claims submitted | $210,000 in submitted charges |
| Numerator | 60 first denials | $18,400 in denied charges |
| Rate for the month | 6.0% | 8.8% |
| What the basis hides | Claim size | Claim count |
The task force excludes rebills from both versions: bill type XX7 on a UB-04, and any CMS-1500 with an R in box 22. A report that counts resubmissions as new claims raises its own denominator and flatters its own rate.
Denial write-off rate: the number that is real money
Denial write-offs as a percentage of net patient service revenue is HFMA MAP Key AR-6. The numerator is the dollars written off as denials in the reporting month, net of recoveries. The denominator is average monthly net patient service revenue. The numerator includes dollars lost when an appeal was denied and dollars the practice chose not to appeal, which is where most of the total comes from.
- Contractual write-offs stay out: the difference between billed charges and the allowed amount is not a denial.
- Patient responsibility stays out, including coinsurance, copays and deductibles.
- Charity care and bad debt stay out.
- Denials reversed on appeal and paid belong in the overturn count, not here.
The direction of travel is down, and the number moves slowly. A write-off is the end of a decision that started two or three months earlier, so a write-off rate that improves this month reflects appeal work from last quarter. Report it monthly, and treat it as the score rather than the steering wheel.
If the write-off rate is the only denial number a practice watches, the first sign of a problem arrives after the appeal window has closed. The weekly numbers are the early warning.
Appeal rate and overturn rate belong on one line
Appeal rate is appeals filed divided by denials received in the same period, with corrected claims and reopenings left out of the numerator. Overturn rate is the task force measure: initial denials overturned and paid divided by initial denials paid and adjusted, computed either on gross charges or on claim volume. Numerator and denominator must cover the same period.
Read them as a pair. In 2024, Medicare Advantage insurers denied 4.1 million prior authorization requests, 11.5 percent of those denials were appealed, and 80.7 percent of the appeals filed were overturned, according to KFF’s analysis of CMS data. Across the largest insurers, the share of denials appealed ranged from 1.6 percent to 19.9 percent. Those figures cover prior authorization requests rather than post-service claims, so read them as a measure of how much gets left on the table, not as a benchmark for your own claim denials.
- Appeal rate low, overturn rate high: the queue is too short. Appeal more of the same categories.
- Appeal rate high, overturn rate low: the filings are weak. Fix the evidence before the next batch.
- Both falling: the denials are getting harder, so re-rank the categories by what each appeal returns.
This is the core of denial management: a queue ranked by reason code and by dollars recovered per appeal filed, worked against a deadline calendar.
Days to appeal and days to resolution
The task force measures two clocks. Time from initial denial to appeal counts the days from the date on the initial denial remittance to the date the appeal was submitted. Time from initial denial to claim resolution counts days from that same remittance to a zero balance, with or without payment. Both are internal process measures, and both should fall.
| Denial | Window to file | Payer decision |
|---|---|---|
| Original Medicare fee-for-service redetermination | 120 calendar days from receipt of the initial determination notice | Within 60 calendar days of the request, plus up to 14 days for each additional evidence submission |
| Medicare Advantage reconsideration, service request | 60 calendar days after receipt of the organization determination notice | Within 30 calendar days of the request |
| Medicare Advantage reconsideration, payment request | 60 calendar days after receipt of the notice | Within 60 calendar days of the request |
| Medicaid managed care plan appeal | 60 calendar days from the date on the adverse benefit determination notice | Within 30 calendar days, extendable by up to 14 |
| Medicaid managed care state fair hearing | 90 to 120 calendar days from the plan’s notice of resolution | State hearing timeframe |
| ERISA group health plan internal appeal | At least 180 days from receipt of the adverse benefit determination notice | Timeframe set by the plan under the regulation |
Every clock above runs from receipt, and receipt is presumed to be five calendar days after the date on the notice unless there is evidence to the contrary. Diarize from the remittance advice date and subtract five days. A redetermination filed on day 118 of a 120 day window is already late.
Denial A/R aging: count days left, not days elapsed
A denial aging report usually buckets claims by how long they have been denied. That is the wrong clock. Original Medicare claims must reach the Medicare Administrative Contractor within one calendar year of the date of service, and that deadline does not move because the claim was denied, appealed or corrected. The appeal window runs on a separate track, measured from the remittance advice. Both belong on the same report.
Calculate the filing deadline from the date of service, once, and keep it on the claim. Do not rebuild it from the denial date.
For Medicare, add 120 days to the presumed receipt date. For a Medicare Advantage or Medicaid managed care denial, add 60.
A 20 day old denial with 30 days left is urgent. A 90 day old denial with 300 days left is not. Elapsed age ranks them backwards.
They carry different deadlines and different owners. A corrected claim fixes the record. An appeal argues the decision.
An unowned denial in a worklist is a write-off with extra steps.
A practice-wide average hides the payer that produces most of the risk.
- Every denied claim carries a date of service and a computed filing deadline.
- Denial A/R is bucketed by days left before the deadline, not days since the denial.
- Appeals and corrected claims sit in separate queues.
- Each denial has one owner and a next action date.
- Denials inside 45 days of a deadline appear on a weekly list.
- The reason code is logged, rather than a free text note.
A practice can build this from the 835 file and the practice management system. A team running outsourced medical billing services should be able to produce the report on request. Either way, the report exists before the deadlines start to bind, or the write-off rate explains afterward what happened.
Questions about denial management KPIs
HFMA’s Claim Integrity Task Force names five: initial denial rate by volume and dollars, primary denial rate, denial write-offs as a percentage of net patient service revenue, time from initial denial to appeal, time from initial denial to claim resolution, and the percentage of initial denials overturned. Add an appeal rate and a denial aging report to see how much denial A/R is inside a closing filing window.
HFMA publishes the formula and the inclusions and exclusions, and it does not publish a target value. Figures in the 5 to 10 percent range are quoted as an industry average, and those numbers usually come from hospital or group data rather than from practices. Set a floor from your own best quarter, then hold it by payer, because a single practice-wide rate hides the payer driving it.
The denial rate counts rework. The write-off rate counts lost money. Denial write-offs as a percentage of net patient service revenue, HFMA MAP Key AR-6, divides net dollars written off as denials by average monthly net patient service revenue, and it includes dollars from appeals that were denied and from denials nobody appealed. It moves two to three months after the denial rate does.
No. A corrected claim or reopening fixes the record: a unit count, a date, a missing modifier, a diagnosis pointer. An appeal argues that the payer’s decision was wrong. Keep them in separate columns, because they carry different deadlines, and a log that mixes them cannot show how often your arguments land.
It depends on the payer. Original Medicare allows 120 calendar days from receipt of the initial determination for a redetermination. Medicare Advantage allows 60 days from receipt of the organization determination notice, and Medicaid managed care allows 60 days from the date on the adverse benefit determination notice. ERISA group health plans must allow at least 180 days. Receipt is presumed five days after the notice date.
Weekly for the leading measures: initial denial rate, appeal rate, and days to appeal. Monthly for denial write-offs and denial A/R aging, because both move slowly and both are outcomes rather than inputs. Run every figure by payer and by reason code at least quarterly, since a practice-wide average hides which payer and which category are producing the work.
The bottom line
Six numbers, one page, one owner. The initial denial rate shows where the claims break, the appeal rate shows how much of that breakage is being fought, the overturn rate shows whether the fight is worth it, and the write-off rate shows what the practice actually lost. The aging report decides which of those claims still has time left.
How much of your denial A/R is inside a closing window?
Send us a month of remittance advice and your denial worklist. We will rebuild the initial denial rate on both bases, split the appeal rate from the overturn rate, age every denial by days left before the deadline, and show you which payer and which reason code to work first. Our team runs medical billing services for medical practices, with a focus on ABA and behavioral health.
Request a free denial KPI auditThis article describes general billing practice and the payer and regulatory requirements in force at the time of writing. Filing windows, contract terms and state Medicaid rules vary, so confirm the deadline and the address printed on your own remittance advice before you file.
