How to Recover 90+ Day Claims in Internal Medicine Billing

There’s a specific kind of dread that comes with pulling up an A/R aging report and seeing a large chunk of it sitting in the 90+ day bucket. At that point, a claim isn’t just late. It’s approaching the point where recovering it takes real effort, and past a certain threshold, some of it may not be recoverable at all.

Aging claims hit cash flow hard, and internal medicine practices tend to feel it more than most. Between chronic disease management, multiple diagnoses per visit, dense evaluation and management coding, and a patient population that often carries several insurance complexities at once, internal medicine billing has more places for a claim to stall than most other specialties.

Timely follow-up and structured denial management aren’t optional extras here. They’re what stands between a practice with healthy, predictable revenue and one that’s quietly bleeding money every month without fully realizing it. This guide walks through exactly what 90+ day claims are, why they pile up in internal medicine specifically, and a complete, step-by-step process for recovering them, along with what to change so they stop piling up in the first place.

What Are 90+ Day Claims?

A 90+ day claim is any submitted claim that remains unpaid, unresolved, or unappealed 90 days or more after the date of service. Claims move into this aging bucket gradually: a claim submitted on day one that isn’t paid, denied, or appealed within the payer’s normal processing window keeps sliding further into aging, and every additional day makes it harder to collect.

Older claims are harder to collect for a few consistent reasons. Payer timely filing and appeal deadlines start closing in. Documentation gets harder to track down as time passes and staff turnover happens. And frankly, aging claims tend to lose priority in a busy billing department, since staff naturally gravitate toward newer, easier-to-resolve claims first.

This is exactly why aging claims are tracked so closely within Accounts Receivable (A/R) management. The relationship is direct: the longer a claim ages, the lower the odds of full recovery, and the more it costs in staff time to eventually resolve.

Understanding the A/R Aging Report

What Is an A/R Aging Report?

An A/R aging report organizes every outstanding claim by how long it has been unpaid, typically grouped into 30-day buckets. Its purpose is simple: give billing staff and practice leadership a clear, prioritized view of exactly where unpaid revenue is sitting and how urgently each group needs attention.

Practices use this report to spot problems early, before a manageable follow-up task turns into a claim that’s genuinely at risk of being written off. The 91+ day bucket deserves immediate, dedicated attention because it represents claims closest to (or already past) many payers’ appeal and resubmission deadlines.

Common Aging Buckets

Why Internal Medicine Practices Have 90+ Day Claims

Internal medicine has a few structural reasons aging claims tend to be more common here than in many other specialties:

• Insurance eligibility issues, especially with patients who have complex or changing coverage
• Benefits verification failures that surface only after a claim is denied
• Prior authorization problems, particularly for diagnostic testing or specialist referrals
• Coding errors across the dense mix of codes internal medicine visits often require
• ICD-10-CM diagnosis coding mistakes, especially with patients carrying multiple chronic conditions
• CPT coding errors, particularly around evaluation and management level selection
• Modifier errors on visits involving multiple services on the same day
• Documentation deficiencies that don’t fully support the billed level of service
• Medical necessity denials tied to unclear or incomplete clinical justification
• Credentialing issues, including lapses that block claims from processing at all
• Coordination of Benefits (COB) problems when a patient has more than one active payer
• Timely filing issues when claims sit too long before initial submission
• Patient balance delays, particularly on high-deductible plans

Common Causes of Aging Claims

Beyond the internal medicine-specific factors above, a few universal culprits show up across almost every aging claims report:

• Claim denials, which stall revenue until they’re investigated and resolved
• Claim rejections, often technical errors that never even reach full payer review
• Missing documentation, forcing a delay while records are located and submitted
• Incorrect provider information, including NPI or taxonomy mismatches
• Duplicate claims, which confuse payer systems and delay resolution
• Underpayments, where a claim is paid but not at the correct contracted rate
• Payer processing delays, sometimes entirely outside a practice’s control
• Appeals pending, where a claim sits waiting on a payer’s appeal review timeline
• Staff follow-up delays, often the simplest and most preventable cause of all

Each of these carries a real financial cost, since every day a claim sits unresolved is a day that revenue isn’t in the practice’s bank account.

Financial Impact of 90+ Day Claims

Aging claims don’t just represent delayed revenue. They actively erode a practice’s financial health:

• Cash flow disruption, since money that should already be collected is still outstanding
• Increased write-offs, as claims that age past appeal deadlines become uncollectible
• Higher collection costs, since older claims take significantly more staff time to resolve
• Reduced profitability, as more revenue gets absorbed by the cost of chasing it down
• Larger Accounts Receivable, which distorts the overall financial picture of the practice
• Poor financial forecasting, since unpredictable aging claims make revenue projections unreliable
• Increased administrative burden, pulling staff attention away from newer, more easily resolved claims

Step-by-Step Process to Recover 90+ Day Claims

Step 1: Prioritize the A/R Aging Report

Start by identifying high-value claims first, since recovering a handful of larger claims often matters more than chasing many small ones. Group claims by payer to spot patterns, and separate straightforward denials from claims that are simply still pending, since they need entirely different next steps.

Step 2: Verify Claim Status

Before doing anything else, confirm exactly where each claim stands: pending, denied, rejected, paid incorrectly, or genuinely lost in the payer’s system. This single step often determines the entire recovery strategy for a given claim.

Step 3: Review Documentation

Pull the progress notes and confirm they support medical necessity for what was billed. Check for physician signatures and identify any missing records before moving forward, since incomplete documentation will sink an appeal even if everything else is handled correctly.

Step 4: Audit Medical Coding

Review the CPT codes, ICD-10-CM diagnosis codes, HCPCS codes if applicable, and modifier accuracy. A coding-related denial can’t be resolved by simply resubmitting the same claim. It needs an actual correction first.

Step 5: Contact the Insurance Company

Call to verify claim status directly, request any additional information the payer needs, and confirm exactly how much time remains on the appeal deadline. Document every interaction, including the representative’s name and reference number, since this record becomes essential if the claim needs to be escalated later.

Step 6: Correct Billing Errors

Depending on what step 2 through 5 revealed, this might mean demographic corrections, coding corrections, documentation updates, or updated eligibility information. Fix the actual root cause, not just the symptom.

Step 7: Appeal Denied Claims

Confirm the payer’s specific appeal requirements and gather the supporting documentation needed to make the case. Track appeal timelines closely, and follow up proactively rather than waiting for the payer to respond on their own schedule.

Step 8: Resubmit Claims

Before resubmitting, run the claim through a full clean claim review and claim scrubbing process. A second denial on the same claim, caused by the same preventable error, is far more damaging than the original delay.

Step 9: Monitor Payment

Review the Electronic Remittance Advice (ERA) carefully once payment comes through, post it accurately, and check for underpayments against the contracted rate. If a secondary payer is involved, make sure secondary billing happens promptly rather than sitting untouched.

Step 10: Analyze Root Causes

Once a claim is resolved, take the time to understand why it aged in the first place. This step is often skipped, but it’s the one that actually prevents the next batch of claims from ending up in the same 90+ day bucket.

Internal Medicine Billing Challenges That Increase Aging Claims

A few specialty-specific factors make internal medicine especially prone to aging claims:

• High patient volume, which leaves less time per claim for careful review
• Chronic disease management, involving recurring visits and detailed documentation requirements
• Evaluation & Management (E/M) coding complexity, where level selection errors are common
• Preventive vs. problem-focused visit coding, which is frequently miscoded or under-documented
• Multiple diagnoses per visit, increasing the odds of an ICD-10-CM specificity issue
• Laboratory and diagnostic testing, adding additional codes and medical necessity requirements to each claim
• Medicare billing rules, which carry their own documentation and coverage nuances
• Chronic Care Management (CCM) billing, with strict time-based and consent requirements
• Transitional Care Management (TCM) billing, which has its own specific timing and documentation rules that are easy to miss

Medicare and Commercial Insurance Considerations

Medicare

Medicare enforces strict timely filing requirements, rigorous medical necessity standards, and detailed documentation expectations, along with its own structured appeals process that internal medicine practices need to follow precisely to avoid losing recovery windows entirely.

Medicaid

State Medicaid programs set their own filing limits and eligibility rules, and coverage differences between states mean a process that works for one state’s Medicaid program may not translate directly to another.

Commercial Insurance

Commercial payers operate under individual contract terms, payer-specific claim edits, their own authorization requirements, and appeal deadlines that can vary significantly from one insurer to the next, making a one-size-fits-all follow-up approach risky.

How to Reduce Future 90+ Day Claims

Prevention is far cheaper than recovery. A few consistent habits make the biggest difference:

• Confirm insurance eligibility verification before every visit, not just for new patients
• Complete benefits verification so coverage details are known upfront
• Secure prior authorization before services are rendered whenever required
• Maintain accurate CPT coding, particularly around E/M level selection
• Prioritize ICD-10-CM coding accuracy and specificity
• Strengthen documentation so medical necessity is always clearly supported
• Run every claim through claim scrubbing before submission
• Perform daily A/R follow-up rather than letting claims sit untouched
• Invest in ongoing staff education as coding and payer rules evolve
• Conduct regular internal billing audits, similar to the process outlined in this medical billing audit checklist

Technology That Helps Recover Aging Claims

The right tools make a measurable difference in how quickly aging claims actually get resolved:

• Electronic Health Records (EHR) that support quick, accurate documentation retrieval
• Revenue Cycle Management Platforms that centralize claim status and follow-up tasks
• Medical Billing Software built to flag claims as they approach aging thresholds
• Claim Scrubbing Software that catches errors before resubmission
• Denial Management Tools that organize and track denial reasons and appeal timelines
• A/R Analytics Dashboards that make aging trends visible at a glance
• AI-Assisted Billing Solutions that help prioritize which claims to work first based on value and recoverability

Key Performance Indicators (KPIs) to Monitor

Reviewing these numbers on a consistent schedule, rather than only when cash flow feels tight, makes it far easier to catch a slipping process before it turns into a serious backlog.

Common Mistakes That Prevent Claim Recovery

A handful of avoidable habits tend to keep claims stuck in the aging bucket longer than necessary:

• Delayed follow-up on claims that should have been worked weeks earlier
• Ignoring small balances that quietly add up across a large patient panel
• Missing appeal deadlines because they weren’t tracked closely enough
• Submitting incomplete documentation with an appeal
• Resubmitting a claim with the same coding error that caused the original denial
• Poor communication with payers, including not documenting calls
• Not tracking A/R metrics consistently
• Failing to identify recurring issues that keep producing the same type of denial

Building an Effective A/R Recovery Workflow

A structured, repeatable workflow beats a reactive, claim-by-claim approach every time:

• Daily aging review, so new claims never sit untouched for long
• Payer prioritization, focusing effort where the volume or value justifies it
• Dedicated follow-up schedules, so aging claims have an assigned owner and timeline
• Escalation procedures for claims that need to move beyond standard follow-up
• Appeals tracking, so deadlines never get missed
• Weekly reporting, keeping practice leadership aware of aging trends in real time
• Continuous process improvement, feeding root cause findings back into daily workflows

How Professional Internal Medicine Billing Services Recover Aging Claims

A specialized internal medicine billing partner typically builds recovery directly into daily operations rather than treating it as a periodic cleanup project:

• A/R follow-up specialists dedicated specifically to working aging claims
• Insurance verification upfront to prevent eligibility-related denials
• Coding audits to catch E/M and diagnosis coding issues before they cause a denial
• Documentation review that flags gaps before submission, not after
• Denial management built as an ongoing process, not a once-a-quarter cleanup
• Appeals management with deadlines tracked closely and proactively
• Claim scrubbing applied consistently, on every claim, every time
• Payment posting handled accurately, including catching underpayments
• Revenue Cycle Management optimization that connects aging claims to broader financial performance
• Monthly performance reporting so practice leadership always knows exactly where things stand

Signs Your Internal Medicine Practice Needs Billing Support

A few warning signs tend to show up well before a practice fully grasps how much revenue is actually at risk:

• More than 20 to 25 percent of total A/R sitting over 90 days
• Rising denial rates month over month
• Slow reimbursements across most payers, not just one
• Frequent coding errors, particularly around E/M level selection
• High write-offs that keep climbing
• Billing staff clearly overwhelmed by volume
• Increasing patient balances that aren’t being addressed
• Declining collections despite steady or growing patient volume

Why Choose The Medicator’s for Internal Medicine Billing Services

Recovering aging claims takes more than good intentions. It takes experienced internal medicine billing specialists who genuinely understand E/M coding complexity, accurate CPT and ICD-10-CM coding practices, and the specific documentation standards internal medicine claims require. The Medicator’s builds insurance eligibility and authorization support directly into the front end of the process, so fewer claims end up aging in the first place.

When claims do stall, comprehensive A/R follow-up, denial prevention, and appeals management keep them from quietly slipping past recoverable timelines. Combined with consistent claim scrubbing, deep Medicare and commercial payer expertise, and ongoing Revenue Cycle Management optimization, the goal is straightforward: fewer claims reaching the 90+ day bucket in the first place, and faster recovery for the ones that do. Transparent reporting and dedicated support mean practices always know exactly where their aging claims stand, month to month.

Conclusion

Recovering 90+ day claims takes more than persistent follow-up. It demands accurate coding, complete documentation, timely appeals, and a genuinely structured A/R management process that doesn’t let claims quietly slip through the cracks. Internal medicine practices, given the sheer complexity of chronic care coding and high patient volume, are especially exposed when that process breaks down.

By identifying root causes, strengthening billing workflows, and monitoring the right key performance indicators, internal medicine practices can meaningfully reduce aging claims and protect their cash flow going forward. Partnering with an experienced internal medicine billing company helps recover revenue that might otherwise be written off, while also preventing the next wave of aging claims before it starts.

If your practice is carrying more 90+ day claims than it should, reach out to The Medicator’s for a free practice analysis and get a clear, honest picture of exactly where your A/R recovery process stands today.

Frequently Asked Questions

What are 90+ day claims?

90+ day claims are submitted claims that remain unpaid or unresolved 90 days or more after the date of service, placing them at high risk of becoming uncollectible.

Why do internal medicine claims remain unpaid for over 90 days?

Common causes include eligibility issues, coding errors, medical necessity denials, prior authorization problems, and delayed staff follow-up, all of which show up more frequently given the complexity of internal medicine visits.

Can old denied claims still be appealed?

In many cases, yes, as long as the payer’s appeal deadline hasn’t passed. That’s exactly why fast, prioritized action on aging claims matters so much.

What is the best way to reduce aging A/R?

A consistent daily follow-up process, accurate upfront eligibility and authorization checks, and strong documentation and coding practices prevent most claims from aging in the first place.

How often should an A/R aging report be reviewed?

Ideally daily for new claims and at least weekly for a full review of the entire aging report, so nothing slips through unnoticed.

Which claims should be prioritized first?

High-value claims and claims closest to appeal or timely filing deadlines should generally be worked before smaller, lower-urgency balances.

How does claim scrubbing help prevent aging claims?

Claim scrubbing catches coding and documentation errors before submission, reducing the number of claims that get denied or rejected in the first place, a step covered in more depth in this look at claim scrubbing in medical billing.

What KPIs should practices monitor?

Days in A/R, percentage of A/R over 90 days, first-pass claim acceptance rate, claim denial rate, net collection rate, and appeal success rate all matter for tracking recovery performance.

How can outsourcing internal medicine billing improve collections?

A dedicated billing partner brings specialized follow-up staff, consistent coding audits, and structured denial management that many internal teams simply don’t have the bandwidth to maintain.

What is an acceptable percentage of A/R over 90 days?

Most well-run practices aim to keep this figure under 20 to 25 percent, though the right benchmark can vary somewhat by payer mix and specialty.

Is there a difference between a claim denial and a claim rejection?

Yes, a rejection typically means a technical error kept the claim from being processed at all, while a denial means the payer reviewed it and declined payment, a distinction explored further in this breakdown of rejections in medical billing.

Does coding accuracy really affect how many claims age past 90 days?

Significantly. Coding errors, especially around E/M level selection and ICD-10-CM specificity, are among the most common and most preventable reasons internal medicine claims stall, a topic covered further in this discussion of how coding and billing intersect.

What internal medicine CPT codes cause the most aging claims?

Evaluation and management codes tend to generate the most aging-related issues, given how frequently level selection and documentation mismatches occur, which is covered in more detail in this guide to internal medicine CPT codes.

Do prior authorization issues really cause claims to age this long?

Yes, especially for diagnostic testing and referrals, since a missing or expired authorization can hold up a claim well past the point where a quick fix is possible.

How does patient communication factor into A/R recovery?

Patient balances make up part of overall A/R, and handling those conversations well matters just as much as payer follow-up, something worth reviewing in this guide to patient collections without hurting the patient experience.

Should small internal medicine practices worry about this as much as larger groups?

Often more so, since smaller practices typically have fewer dedicated staff to keep up with daily A/R follow-up on top of everything else running the practice.