AR follow-up in medical billing is the structured process of tracking every submitted claim, insurance and patient balance alike, until it’s paid, appealed, or formally written off. Some people write it out in full as accounts receivable follow-up, especially in a payer letters, where apparently brevity is against the rules.
It runs on a different rulebook than collections and a much friendlier one. The problems that show up in an aging report almost always started long before a balance got close to that stage.
Initial claim denial rates hit 11.81% in 2024 across more than 2,100 hospitals and 300,000 physicians. True days in accounts receivable climbed another 5.2% over the same period (Kodiak solutions, 2025).
For every 100 claims a practice submits, about 12 boomerang straight back unpaid, uninvited and unimpressed. The real question isn’t whether your team follows up, it’s whether the problem started before the claim ever left the building.
This guide moves through six areas, in order, like a checklist that actually wants to see you succeed.
- What AR follow-up includes, and where it stops
- The AR follow-up process, phase by phase
- The upstream causes behind aging claims
- AR follow-up versus denial management
- The metrics and benchmarks worth tracking
- When a claim earns a write-off instead of another call
TLDR: The 90-second AR autopsy
Before the full walkthrough, this is the compressed version, the kind you forward to your billing lead with zero context and thumbs-up emoji.
- AR follow-up tracks every unpaid claim from submission to resolution, which is a wider job than denial management (that one’s just the moody subset that only shows up once a payer says no).
- Structured AR follow-up should start at 30 to 45 days post-submission, with the 60 to 120 day window getting the most aggressive attention, the AR equivalent of a code red.
- Most claims aging past 90 days trace back to something upstream, an eligibility lapse, a missing authorization, a coding error, or a payer information request nobody answered in time.
- Healthy benchmarks sit in a fairly narrow range: days in AR under 40, less than 20 to 25% of AR sitting past 90 days, and a net collection rate close to 97%.
- Write-offs work best as a deliberate decision built on dollar thresholds, filing deadlines, and provider approval, not as the default outcome when follow-up runs out of road.
- Behavioral health, surgical, and multi-location practices each hit different AR obstacles, so one generic AR follow-up script rarely holds up across all of them.
What AR follow-up means in medical billing
AR follow-up in medical billing is the ongoing work of tracking every open claim and patient balance until it reaches a real resolution (paid, denied and appealed, or written off).
It is not the same as external collections, which only shows once a legitimate billing effort has already thrown up its hands and called for backup.
AR follow-up is the effort that’s supposed to make collections unnecessary in the first place. Some people call the successful side of this work AR recovery in medical billing, since recovering payment on a legitimate claim is the entire point of following up on it. That stake runs highest for small practices without a dedicated follow-up team, which is exactly where focused strategies for boosting AR recovery in small practices make the biggest difference.
Accounts receivable, the entity underneath all of this, covers more ground than most people assume. Treating it as “insurance claims only” is a common way practices undercount what they’re actually managing. A complete AR follow-up scope includes the following.
- Outstanding insurance claims still active with a payer
- Denied claims sitting inside an appeal window
- Patient balances left over after insurance adjudication
- Payment plans still being tracked toward completion
An AR aging report is the tool that turns all of that into something sortable. It groups every open balance into AR aging buckets 30, 60, 90, and 120-plus days based on how long it has been sitting unpaid.
The report itself doesn’t fix anything (it just tells a biller where to look first, which is still more useful than it sounds). HFMA’s MAP Initiative frames this kind of tracking around actionable denials specifically, treating continuous monitoring as a core revenue cycle KPI rather than a task that happens once a month.
Days in AR, the companion metric to the aging report, measures the average number of days a claim or balance stays unpaid across the whole portfolio.
A practice with clean processes keeps that number low. A practice with upstream problems, the kind covered later in this guide, watches it climb no matter how many calls get made.
Inside the AR follow-up process, step by step
The AR follow-up process runs in three phases:
- Identification and prioritization
- Payer contact and investigation
- Resolution and payment posting
Each phase has its own clock, and its own way of going wrong. Skipping straight to phase two without doing phase one properly is how practices end up chasing low-value claims while six-figure balances quietly age past their filing deadline.
Identification and prioritization
This phase starts with the AR aging report, sorted by both age and dollar value. A $40 balance at 100 days and a $4,000 balance at 100 days simply do not deserve the same amount of attention.
Claims should hit the AR follow-up queue starting around 30 to 45 days post-submission, before they drift into the buckets where recovery odds start dropping.
A representative pattern shows up constantly in practices without a prioritization rule. A biller works through the aging report top to bottom by date alone, clears a dozen small balances, and lets a handful of large ones drift straight toward their filing deadline.
The table below shows how priority and action shift as a claim ages.
| Aging bucket | Days outstanding | Priority level | Typical action |
| Fresh | 0 to 30 | Monitor | Confirm clearinghouse acceptance, watch for early rejections |
| Early aging | 31 to 60 | Standard | First payer contact if there has been no response |
| Escalating | 61 to 90 | High | Escalate to phone contact, document the CARC or RARC code |
| Critical | 91 to 120 | Urgent | Check the appeal window against the timely filing limit |
| Write-off review | 120+ | Provider decision | Evaluate for write-off or continued pursuit |
Where a claim sits decides what happens next
Payer contact and investigation
This is the part most people picture when they hear “claim follow-up medical billing,” and it earns that reputation honestly.
It usually means calling the payer directly, since portals update on their own private schedule, wherever they feel like it. That call means checking the claim status and pulling the CARC or RARC code that explains exactly why a claim hasn’t paid.
Every interaction gets logged with a date, the representative’s name, a reference number, and the next action, since an undocumented phone call is functionally the same as a call that never happened.
Payer follow-up isn’t uniform across the board either. Some payers respond fastest through portal inquiries, others require a phone call before anything moves, and a few maintain their own reconsideration process that skips the formal appeal step entirely.
Building payer-specific guideline sheets, essentially a cheat sheet per payer, is what keeps AR follow-up from turning into guesswork every single time. That becomes especially useful once a practice is juggling more than a handful of payer contracts at once.
Resolution and payment posting
Resolution means the claim reaches a real endpoint rather than simply going quiet, and that endpoint usually takes one of four forms.
- Paid in full
- Approved for write-off
- Paid with an adjustment
- Denied and moved into appeal
Payment posting matches the payment against the EOB or ERA to confirm the amount lines up with the contracted rate, catching underpayments before they slip past unnoticed. A claim that closes without this check isn’t actually resolved. It’s just quiet for now, which is a very different thing.
Why claims really age: the upstream root causes of AR problems
Claims rarely age because a biller forgot to make a call. They age because something broke before the claim was ever submitted. The aging bucket is just where that failure eventually surfaces, well after the actual damage was done. The most common upstream causes include the following patterns.
- Coding errors caught only after adjudication
- Payer information requests that stall in someone’s inbox
- Missing prior authorizations for procedures that required one
- Eligibility lapses that go unnoticed until the claim comes back denied
- Credentialing gaps that block payment entirely, regardless of how clean the claim is
- Coordination of benefits disputes when primary and secondary payers disagree on order
These patterns line up closely with the common claim denial mistakes that quietly push claims into the aging report long before anyone notices them. A clean claim, one that passes every payer edit without a single hitch, can still get denied if the coverage behind it changed without anyone noticing. That’s the plot twist nobody asked for in revenue cycle work.
The claim did everything right, and it still failed for a reason that had nothing to do with the claim itself. Coordination of benefits disputes follow the same pattern, since a claim can sit in AR follow-up limbo for weeks while two payers quietly disagree about who pays first.
The scale of this problem is bigger than most follow-up teams realize. Requests for information alone delayed roughly $6 billion in claims during just the first five months of 2024, a pace that projects to $14.4 billion annually (Kodiak Solutions, 2024).
Experian Health’s 2024 survey found that 74% of revenue cycle leaders reported increasing claim denials, 66% reported longer reimbursement times, and 77% pointed directly to shifting payer policy as the driver.
McKinsey & Company’s 2025 research adds another layer. Organizations write off an average of 2.63% of net patient service revenue to clinical denials alone, and that number has nothing to do with how fast anyone picks up the phone.
What happened upstream, and where it shows up in AR
The pattern worth noticing is that none of these failures show up as their own line item on a report. They show up disguised as an aging claim, which is exactly why so many practices spend their energy treating the symptom instead of the disease sitting a few steps upstream.
AR follow-up vs denial management, and where they split
AR follow-up is the umbrella process of working every outstanding claim.
Denial management is the specialized subset, the moody teenager of AR follow-up that only handles shows up once a payer says no.. For the full breakdown of that specialized process, see our guide to mastering denial management. All denial management is AR follow-up. Not all AR follow-up involves a denial (a claim can age for months while simply awaiting adjudication, with no denial in sight).
Every denial is an AR problem, but not every AR problem is a denial. Mixing the two up is how practices end up under-resourcing the broader tracking work in favor of firefighting denials alone.
Roughly 90% of denials get identified through ERA responses, and of those, about 70% are fixable with a modifier correction or another minor change. The remaining 30% genuinely need input from the provider or clinical staff before anyone can move forward.
That last group is where the line between AR follow-up and denial management gets blurriest, since resolving it takes more than a phone call to the payer.
| Attribute | AR follow-up | Denial management |
| Scope | Every outstanding claim, denied or not | Only claims a payer has denied |
| Trigger | Claim submission | A denial notice or explanation of benefits |
| Goal | Resolve every open balance | Overturn or resolve a specific denial |
| Timeline | Starts around 30 to 45 days post-submission | Starts the moment a denial hits the account |
| Typical next step | Contact payer, confirm status | File an appeal inside the timely filing limit |
A claim moves through a fairly predictable arc, from AR follow-up, to appeal, to write-off. It starts in general AR follow-up the moment it’s submitted, with AR recovery as the goal at every stage of that arc.
If it comes back denied, it shifts into denial management, where an appeal gets filed within the timely filing limit and supported with the right clinical justification. Even a well-documented appeal can stall on avoidable insurance denial mistakes, which is why catching them before submission matters as much as the appeal itself.
If that appeal fails, or the claim ages past the point where pursuing it still makes financial sense, it moves into the write-off decision covered next.
AR follow-up metrics that matter
AR follow-up metrics fall into a short list worth tracking closely, and the table below breaks each one down. Together, they show whether the process is actually working, or just staying busy, which billing teams have historically been excellent at confusing with each other.
| Metric | What it measures | Healthy benchmark |
| Days in AR | Average time a claim stays unpaid | Under 40 days |
| AR over 90 days | Share of AR sitting past 90 days | Under 20 to 25% |
| Net collection rate | Percent of allowed revenue actually collected | 95% or higher |
| Denial rate | Share of claims denied on first submission | Under 10% |
| First-pass resolution rate | Claims paid without rework | 90% or higher |
| AR follow-up cycle time | Days between one follow-up touch and the next | 14 business days or less |
Net collection rate deserves a closer look, since it’s the metric most often confused with gross collection rate. Net collection rate measures what actually got collected against what was contractually allowed, not against the full billed charge. The gap between the two is usually where revenue leakage in medical billing hides in plain sight.
A practice can look fine on paper while quietly losing money to underpayments that never get caught, like a bank account that seems healthy right up until someone actually read the statement.
This is exactly why AR follow-up and revenue leakage medical billing tracking belong in the same conversation instead of two separate reports nobody cross-checks.
The gap between current performance and target performance is wider industry-wide than most practices assume. Guidehouse’s 2024 research found nearly 30% of healthcare leaders reporting final denial rates between 3.1% and 5%, well above the 1% benchmark most revenue cycle teams should be aiming for.
HFMA’s MAP Initiative recommends measuring denial rate against actionable denials specifically, since lumping in denials nobody could have prevented distorts the number in a way that hides the real problem.
The write-off decision: when to stop pursuing a claim
A claim earns a write-off recommendation when the cost of continuing to chase it outweighs the realistic odds of ever collecting it, not simply because AR follow-up has dragged on for a while.
A write-off should be a decision someone makes on purpose, not something that happens by default once a biller gets tired of a claim.
Consider a mid-sized surgical practice holding a $2,800 balance stuck at 130 days over a modifier dispute.
The write-off decision there isn’t about giving up, it’s about whether four more collection attempts are worth more than the $2,800 itself, or whether the practice is just paying someone to keep dialing a payer who decided months ago to ignore them.
Four checks typically drive the decision.
- How much money is actually at stake, and does it justify more staff time
- How close the claim is to its timely filing limit or appeal deadline
- Whether the denial reason suggests a real path to payment or a dead end
- Whether the provider has formally signed off on letting the balance go
Four checks before a claim gets written off
In practice, this is less about giving up and more about knowing when a claim has stopped being an AR follow-up problem and started being a sunk cost. A well-run revenue department holds claims in the 60 to 120 day bucket as its top AR follow-up priority.
Anything crossing 120 days gets formally evaluated for write-off, with the provider making the final call rather than a biller deciding alone. That structure is what keeps write-offs from becoming a quiet, unaccounted-for leak instead of a documented business decision.
How specialty changes the AR follow-up playbook
AR follow-up in medical billing doesn’t run the same way across specialties.
Treating it like one generic process is how practices end up surprised by problems a specialty-aware team would have seen coming.
Accounts receivable follow-up for a solo behavioral health practice looks nothing like accounts receivable follow-up for a twelve-location surgical group, even though both practices are technically doing “the same job” in the same way a golden retriever and cat are technically both pets.
Payer behavior, authorization requirements, and eligibility patterns all shift by specialty, so the AR follow-up cadence has to shift with them.
Behavioral health practices
Rolling eligibility is the defining headache here, since behavioral health coverage can change month to month in ways that other specialties rarely deal with, almost like it enjoys keeping biller on their toes.
Medical necessity scrutiny also runs heavier, which means payer review cycles for behavioral health claims tend to run longer than the industry average.
Follow-up teams working this specialty typically build eligibility re-verification into every single visit, not just the first one.
Surgical practices
Bundling issues and modifier errors dominate the surgical AR conversation, especially around global surgery packages and NCCI edits that group multiple procedures into a single payment.
A claim that looks correct on submission can still get denied if the modifier doesn’t clearly separate a distinct, billable service from the bundle.
Surgical AR follow-up leans heavily on documentation that ties each code back to a specific, separately identifiable service. That documentation is usually the only thing standing between a paid claim and a bundling denial.
Multi-location groups
Per-location AR ownership becomes the priority once a practice operates across more than one site. A single shared AR queue tends to hide which location is actually falling behind.
Dedicated teams assigned by location, each reporting on their own aging buckets, catch problems faster than one combined report ever could.
Multi-location practices also deal with payer enrollment differences by state, which adds another layer most single-site practices never have to think about.
SUD agencies
Commercial payer enrollment complexity and facility contracting sit at the center of AR challenges for substance use disorder agencies, since a single case agreement or an out-of-network gap can stall reimbursement for weeks.
Continued-stay authorizations also need constant tracking, since a lapse mid-treatment creates exactly the kind of upstream failure that shows up later as an aging claim. SUD billing tends to reward practices that treat authorization tracking as a daily task rather than a weekly one.
Stop letting aging claims write their own ending
Every problem covered in this guide, the upstream failures, the payer obstacles, the write-off decisions nobody wants to make alone, is exactly what MedHeave was built to own.
MedHeave operates as an embedded revenue department rather than a distant billing vendor who calls once a quarter to say things are “mostly fine”.
That means AR follow-up isn’t a task that gets squeezed in between other work. It’s a standing responsibility with its own cadence, its own accountability, and its own reporting.
- First action on assigned AR within 24 hours
- AR follow-up on open claims every 14 business days
- Recovery rate of 80 to 90% on worked accounts still inside their filing window
- Claims beyond 120 days evaluated for write-off with provider approval required, never a default
- Dedicated AR teams per location for multi-site practices, so no site quietly falls behind
- Payer-specific guideline sheets built per practice, so AR follow-up stops depending on guesswork
Ready to find out what’s actually driving your AR numbers, instead of just guessing and hoping the next payer call goes better? Contact our AR recovery services team and let’s take a real look at your aging report.
Frequently asked questions
Here are some commonly asked questions on this topic:
Structured AR follow-up should begin at 30 to 45 days post-submission rather than waiting for a payer to act first. Waiting longer lets claims drift toward the 90-plus day buckets, where recovery rates start dropping noticeably. Starting early also makes it easier to catch a stalled claim before it becomes a full denial, while there’s still time to fix a simple error. The earlier a claim enters the queue, the more options remain on the table, and the fewer surprises show up once the timely filing limit gets close.
A healthy days-in-AR benchmark sits under 40 days for most medical practices, well below the industry standard of 60 to 70 days. Alongside that, less than 20 to 25% of total AR should be sitting past 90 days at any given time. Both numbers together give a clearer picture than either one alone. A low days-in-AR figure with a high 90-plus percentage usually points to a small number of badly stuck claims dragging the average down.
Claims aging past 90 days typically trace back to upstream issues rather than a lack of AR follow-up effort. Eligibility failures, missing authorizations, coding errors, and unresolved payer information requests are the most common culprits. These problems tend to surface only once a claim is already deep into the aging report, which is what makes them easy to miss earlier on. Fixing the upstream process usually does more for the number than adding another round of calls.
Payer requests for information, often called RFIs, delayed roughly $14.4 billion in healthcare payments in 2024 alone (Kodiak Solutions, 2024). Each one requires pulling documentation, resubmitting it, and waiting through another review cycle, adding real weeks to the payment timeline. RFIs also tend to land in queues that nobody owns, which is exactly how they end up ignored past their response deadline. Assigning clear ownership for RFIs is one of the simpler fixes available to most practices.
A practice should consider outsourcing AR follow-up once internal staff can no longer maintain a consistent follow-up cadence or appeal deadlines start slipping through the cracks. It’s also worth considering once AR sitting past 90 days consistently exceeds 25% of the total, since that pattern rarely resolves on its own. Outsourcing works best when it adds dedicated ownership rather than just more hands doing the same disorganized process. The goal is structure, not simply more people making calls.
