In 2026, the stakes are higher. Payers are scrutinizing claims more closely, filing windows keep shrinking, and denial rates are climbing. Sixty percent of medical-group leaders reported higher denial rates in 2024 than the year before, and that pressure hasn't let up.
This guide breaks down the AR follow-up process, the KPIs that actually matter, a step-by-step workflow, common mistakes, and how to know when outsourcing makes financial sense.
Key Takeaways
- AR follow-up recovers unpaid and underpaid claims after submission until payment or final resolution
- Healthy practices keep Days in AR under 35-40 with denial rates below 8-10%
- Claims aging past 60-90 days become harder to collect
- Behavioral health and TMS billing face unique AR delays from prior auth and coding complexity
- Outsourced AR follow-up can save providers 15+ hours weekly and collect revenue that would otherwise age out
What Is AR Follow-Up in Medical Billing?
AR follow-up is the ongoing work of tracking unpaid or partially paid claims and pushing them toward resolution. It sits in the middle of the revenue cycle — after you submit a claim, before you post final payment.
It runs as a continuous loop: check claim status, find why payment stalled, then take corrective action until the balance clears.
AR follow-up vs. denial management:
| Factor | AR Follow-Up | Denial Management |
|---|---|---|
| Scope | All unpaid/underpaid claims | Specifically denied claims |
| Timing | Starts at submission, continues until paid | Begins after a denial is received |
| Objective | Monitor and collect | Investigate root cause, correct, and appeal |
Denial management is a subset of AR follow-up: the more complex work of diagnosing why a payer refused the claim.
What Does an AR Denial Mean in Medical Billing?
A denial is a payer's formal refusal to pay a claim as submitted. It is not the end of the road, but every denial needs root-cause investigation before you resubmit or appeal.
Common triggers include:
- Coding errors
- Missing modifiers
- Eligibility mismatches
Skip that diagnosis step, and the same denial often comes back on resubmission.
What Is the Difference Between AR and WIP?
AR is money owed to you after a claim has been submitted — it's sitting with the payer or patient waiting on payment. WIP (Work in Progress) refers to claims that haven't been submitted yet, meaning charges still being coded, scrubbed, or prepared. Think of WIP as pre-submission and AR as post-submission.
The Step-by-Step AR Follow-Up Process
A disciplined AR workflow follows a predictable rhythm.
- Segment the aging report — Break claims into 0-30, 31-60, 61-90, and 90+ day buckets. Older buckets need faster attention since recovery odds drop the longer a claim sits.
- Verify claim status — Check payer portals, clearinghouses, or call payer representatives to pinpoint the delay or denial reason.
- Take corrective action — Resubmit corrected claims, send supporting documentation, or file an appeal within the payer's specific timeline. Miss the window, and the claim may become unrecoverable.
- Follow up consistently — Set a recurring cadence by aging bucket and payer. Keep working each claim until it pays, adjusts, or exhausts the appeal path.
- Post payment and close the claim — Reconcile against the EOB or ERA and close out accurately.
The cost of inconsistency is steep. As many as 60% of returned claims are never resubmitted at all, according to AHIMA, meaning practices are simply writing off money they've already earned. Reworking a claim costs an average of $25 per claim, which is still far cheaper than abandoning it.
One term that often gets mixed into this discussion is AR entry (sometimes searched as "AR entry in hospital"). It means logging billable charges into the AR ledger right after a patient encounter, before the claim is submitted. That step starts the revenue cycle; it is not part of the follow-up phase itself.
Key AR Follow-Up KPIs and Benchmarks
You can't manage what you don't measure. These are the numbers that matter most:
| KPI | Benchmark | Why It Matters |
|---|---|---|
| Days in AR | Under 35-40 days | Shows how fast you're actually getting paid |
| Clean claim rate | 98% target | Fewer errors mean fewer denials upfront |
| Denial rate | Under 8-10% | High denial rates signal front-end problems |
| AR aged 90+ days | Under 10-15% | Older claims are far less likely to be collected |
| Collection rate | As close to 100% as possible | Measures actual dollars received vs. expected |
Clean claim rate and first-pass resolution are your early warning system. If claims aren't going out clean the first time, you're creating AR problems before they even start.
Persistex maintains a 98% clean claim rate across its client base by scrubbing and verifying every claim before submission. That catch keeps today's coding or eligibility errors from becoming tomorrow's denials.
Common AR Follow-Up Challenges in Behavioral Health and TMS Billing
Behavioral health and TMS billing come with extra layers of complexity that generic billing teams often miss. TMS therapy authorization requirements. CPT codes 90867-90869 carry strict rules — 90867 can only be reported once per treatment episode and not more than once within six weeks, and 90869 shouldn't be billed alongside 90867 or 90868. Miss these rules, and claims stall in AR or get denied outright. Behavioral health coding nuances. Psychotherapy codes (90832-90838) and psychiatric evaluation codes (90791/90792) each carry specific documentation requirements. Payers scrutinize session frequency, medical necessity, and treatment plans closely. Persistex focuses its billing and AR follow-up work on these behavioral health pain points:
- CPC, CPB (AAPC), RHIT, and CCS (AHIMA) certified team
- 35% average reduction in coding-related denials
- Coding reviewed against major payer rules, including MassHealth and other New England policies
- Prior authorization support aimed at fewer stalled claims before they age in AR One multi-provider behavioral health clinic came to Persistex with a 35% denial rate across 8 providers and unpredictable cash flow. Specialty coding and persistent follow-up brought that AR back under control.
Should You Outsource AR Follow-Up or Handle It In-House?
There's no universal right answer here, but the tradeoffs are clear.
In-house AR follow-up:
- More direct control over the process
- Higher fixed staffing costs
- Harder to scale during volume spikes or staff turnover
Outsourced AR follow-up:
- Cost-efficient, often percentage-based pricing
- Scales with claim volume automatically
- Gives you payer-specific and specialty expertise without hiring
Signs it's time to outsource:
- Your 90+ day AR balance keeps climbing month over month
- A denial backlog is growing faster than your team can work it
- Staff spend more time correcting old claims than submitting new ones
When those signs show up, a specialized billing partner often closes the gap faster than adding headcount. Persistex clients have seen 40% fewer denials, AR days cut from 90 to 30, and a dedicated named account team instead of a rotating call center queue.
One solo psychiatry practice owner who was spending 15+ hours a week on billing recovered that time and saw 28% revenue growth after outsourcing.
Frequently Asked Questions
What is the AR follow-up process?
AR follow-up is the cycle of reviewing aging reports, checking claim status with payers, resolving denials or delays, and following up until the claim is paid and closed.
What does an AR denial mean in medical billing?
A denial is a payer's formal refusal to pay a claim as submitted. It requires root-cause investigation to correct the underlying issue before resubmission or appeal.
What is the difference between AR and WIP?
AR is money owed after a claim has been submitted to a payer. WIP (Work in Progress) refers to claims still being coded or prepared that haven't been submitted yet.
What is AR entry in medical billing?
AR entry is the process of logging billable charges into the accounts receivable ledger immediately after a patient encounter, before the claim submission process even begins.
How often should AR follow-up be performed?
Weekly reviews are the standard recommendation, with active follow-up beginning around day 25-30 post-submission before claims start aging into riskier buckets.
When does it make sense to outsource AR follow-up?
When your 90+ day AR balance or denial backlog keeps growing despite in-house effort, outsourcing to a specialized partner like Persistex is often the practical next step.
