AR Follow-Up in Medical Billing: Complete Guide for Providers

Accounts receivable can look straightforward on a billing report: a claim was submitted, payment has not arrived, and someone needs to follow up. In actual healthcare revenue cycle operations, however, AR follow-up in medical billing involves much more than checking whether a payer has paid a claim. A balance may be sitting because of a coding error, missing authorization, eligibility problem, medical necessity issue, incorrect payer information, coordination-of-benefits conflict, documentation request, underpayment, duplicate claim, or a denial that requires a formal appeal.

Poor AR follow-up can result in delayed payments, avoidable write-offs, repeated claim submissions, incorrect reimbursement, unresolved denials, and compliance exposure. On the other hand, aggressive follow-up without understanding the payer’s rules can create duplicate claims, inappropriate patient billing, or inaccurate account adjustments.

For providers, hospitals, clinics, and physician practices, effective AR management connects clinical documentation, diagnosis coding, CPT/HCPCS reporting, claim submission, payer adjudication, remittance analysis, denial management, appeals, and patient responsibility. The objective is not simply to “collect old claims.” The objective is to determine why the money has not been received, what action is appropriate, who must take it, and when the account should be resolved or escalated.

This guide shows the AR follow-up process, billing and accounts receivable terms, claim status steps, common AR rejections, in medical billing, coding rules, paperwork rules, payer follow-up plans, aging control, appeals and useful performance metrics.

What Is AR Follow-Up in Medical Billing?

AR follow-up in medical billing is the process of reviewing unpaid, underpaid, denied, rejected, or otherwise unresolved healthcare claims and taking the appropriate action to obtain accurate payment or properly resolve the balance.

AR stands for accounts receivable. In healthcare, an account receivable generally represents money owed to a provider for services already rendered but not yet collected.

A typical AR account can contain:

• Claims awaiting payer adjudication
• Claims that were denied
• Claims that were rejected before adjudication
• Claims that were partially paid
• Claims awaiting medical records
• Claims pending authorization review
• Claims affected by coordination of benefits
• Patient-responsibility balances
• Secondary claims awaiting submission
• Underpayments requiring contract review
• Claims approaching a payer’s filing or appeal deadline

The purpose of follow-up is to move each account toward a defensible resolution.

That resolution might be:

1. Corrected claim submission
2. Additional documentation
3. Payer reconsideration
4. Formal appeal
5. Secondary billing
6. Patient billing when appropriate
7. Contractual adjustment
8. Corrected payment
9. Administrative correction
10. Proper write-off when no further collectible amount remains

AR follow-up should therefore be viewed as a decision-making process, not simply a phone-call activity.

Why Is AR Follow-Up Important in Medical Billing?

A strong AR process protects both the provider’s revenue and the accuracy of its financial records.

When claims remain unresolved, the practice can experience:

• Increasing days in accounts receivable
• Cash-flow problems
• Higher denial rates
• Missed filing deadlines
• Unnecessary patient statements
• Incorrect contractual adjustments
• Underpayments
• Increased administrative workload
• Greater audit exposure
• Inaccurate financial reporting

The connection between medical billing and accounts receivable begins before a claim ever reaches the payer.

For example imagine a provider does a procedure that makes sense from a point of view but the claim has the wrong CPT code or is missing the diagnosis details the payer needs. The AR representative might find out about the denial later. The real problem started when the documentation was done or when the coding was done or when the charges were recorded or when the claim was prepared.

This is why AR performance should be analyzed together with:

Documentation → Coding → Charge Capture → Claim Submission → Payer Adjudication → Payment → AR Follow-Up → Resolution

AR Follow-Up in Medical Billing: What Happens After a Claim Is Submitted?

Once a claim is submitted, the account enters a lifecycle.

1. Claim Acceptance

The clearinghouse or payer confirms whether the claim passed basic electronic or formatting edits.

An accepted claim is not necessarily a paid claim.

Acceptance generally means the claim was received for processing. It does not guarantee that the payer will approve the services.

2. Adjudication

The payer evaluates the claim against applicable benefit, eligibility, coding, coverage, authorization, medical necessity, contractual, and administrative rules.

The payer may:

• Pay the claim
• Partially pay the claim
• Deny the claim
• Pend the claim
• Request documentation
• Apply patient responsibility
• Apply a contractual adjustment

3. Remittance

The provider receives an explanation of how the claim was processed through an electronic remittance advice, explanation of benefits, or another payer communication.

AR staff should review more than the payment amount.

The remittance should be examined for:

• Claim status
• Allowed amount
• Paid amount
• Patient responsibility
• Contractual adjustment
• Denial reason
• Remark codes
• Recoupment
• Bundling
• Timely filing issues
• Medical necessity issues
• Missing information
• Authorization problems

4. Follow-Up

If the claim remains unresolved, the account is assigned for follow-up.

The representative should determine:

What happened? → Why did it happen? → What evidence supports correction? → What action is required? → Who must take that action? → When should the account be checked again?

2026–2027 Coding and Billing Version: What Providers Need to Know

AR follow-up is date-sensitive because the claim itself is date-sensitive.

As of September 14, 2026, providers need to pay particular attention to the transition between FY 2026 and FY 2027 ICD-10-CM.

The FY 2026 ICD-10-CM rules apply through September 30, 2026. The FY 2027 ICD-10-CM files become applicable to patient encounters and discharges beginning October 1, 2026. The federal government has already published the FY 2027 ICD-10-CM files for that transition.

CPT has a separate annual cycle. The American Medical Association published the CPT 2027 code set in September 2026. However the arrival of a code set does not mean that health care professionals should use the 2027 CPT codes for services that happened in 2026. The correct CPT edition and the rules, from the insurance company need to be decided based on the date when the service was provided and the billing rules that apply.

For AR follow-up, this matters when correcting a claim. A representative should not automatically replace a code with the newest available code. The correction must reflect the services actually furnished and the code set applicable to the claim.

Is There a CPT, ICD-10, or DX Code for AR Follow-Up?

No single CPT, ICD-10-CM, or diagnosis code represents AR follow-up in medical billing.

This is one of the most important points for providers and billing professionals.

AR follow-up is a revenue cycle activity, not a diagnosis or clinical procedure.

CPT codes

CPT codes describe medical services and procedures reported by physicians and other qualified healthcare professionals. AR follow-up itself is generally not represented by a dedicated CPT code.

For example, calling a payer to investigate a claim does not automatically create a billable CPT service.

ICD-10-CM codes

ICD-10-CM codes describe diagnoses and conditions. There is no general ICD-10-CM diagnosis code meaning “accounts receivable follow-up.”

The ICD-10-CM code appearing on an AR claim should represent the patient’s documented diagnosis or reason for the encounter, according to the applicable coding rules.

DX codes

“DX code” is commonly used to mean diagnosis code. In U.S. professional and institutional billing, this generally refers to the applicable ICD-10-CM diagnosis code.

The diagnosis should not be changed simply because a claim is in AR.

CARCs and RARCs

The codes that are especially important during AR follow-up are often Claim Adjustment Reason Codes (CARCs) and Remittance Advice Remark Codes (RARCs).

CARCs explain why an adjustment was made to a claim or service. RARCs provide additional explanation or remittance information.

Therefore, an AR representative may be working with:

CPT/HCPCS + ICD-10-CM + modifiers + payer policy + CARC + RARC + claim status

rather than an “AR follow-up code.”

Master Reference Table: Codes and Information Used During AR Follow-Up

AR Scenario	Code/System	What It Tells the Provider
Diagnosis reported on claim	ICD-10-CM	Identifies the documented diagnosis or condition supporting the service
Procedure/service	CPT	Identifies many professional medical services and procedures
Supplies, drugs, certain services	HCPCS	Reports services and items not represented solely by CPT
Claim adjustment reason	CARC	Explains the reason for an adjustment or denial
Additional remittance explanation	RARC	Provides supplemental or informational explanation
Procedure performed during inpatient stay	ICD-10-PCS, when applicable	Used for applicable inpatient hospital procedure coding
Place of service	POS code	Identifies where the service was provided
Claim status	Payer/clearinghouse status code or message	Indicates whether a claim is pending, accepted, rejected, paid, or otherwise processed
Authorization	Payer authorization/reference number	Connects the service with an approved authorization when required
Coordination of benefits	Payer/claim information	Helps determine primary and secondary responsibility
Payment	Remittance information	Shows paid, allowed, adjustment, and responsibility amounts

There is therefore no finite list of “CPT codes for AR follow-up” or “ICD-10 codes for AR follow-up.” The relevant clinical codes depend on the actual service and diagnosis on the underlying claim.

Common AR Denials in Medical Billing

AR denials can arise from many different points in the revenue cycle. The correct response depends on the exact denial reason.

Eligibility and Coverage Denials

Examples include:

• Patient not eligible on date of service
• Coverage terminated
• Incorrect member identification
• Wrong payer billed
• Service excluded under the benefit
• Coordination-of-benefits issue

The first step is to verify coverage for the actual date of service.

Do not assume that current eligibility means the patient was eligible on the date of treatment.

Authorization and Referral Denials

A payer may deny a service because required prior authorization, referral, notification, or certification was absent or invalid.

AR follow-up should determine:

• Whether authorization was actually required
• Whether authorization existed
• Whether the authorization covered the specific service
• Whether the authorization number was submitted correctly
• Whether the provider, facility, diagnosis, procedure, units, or dates matched the authorization
• Whether the payer’s policy permits retrospective authorization or reconsideration

Do not create or alter authorization information merely to make a claim payable.

Medical Necessity Denials

Medical necessity denials require closer review.

The representative should compare:

Provider documentation + diagnosis code(s) + CPT/HCPCS code(s) + payer coverage policy + submitted modifiers + supporting records

A diagnosis code should not be added merely because it would make a service payable.

The medical record must support the diagnosis and service.

Coding Denials

Coding-related AR problems can involve:

• Incorrect CPT code
• Incorrect HCPCS code
• Invalid modifier
• Diagnosis-procedure mismatch
• Missing diagnosis
• Incorrect units
• Bundling
• Mutually exclusive services
• Incorrect place of service
• Incorrect global-period reporting
• Incorrect sequencing
• Unsupported level of service

The appropriate solution is to review the documentation and coding rules—not simply select the code that produces the highest reimbursement.

Duplicate Claim Denials

A claim may be denied as a duplicate when the payer believes the same service was submitted more than once.

Before resubmitting, determine whether the original claim:

• Was already paid
• Is still processing
• Was rejected
• Was denied
• Was submitted with a different claim number
• Requires a corrected claim instead of a new claim

Repeatedly sending the same claim can complicate AR resolution.

Timely Filing Denials

Timely filing is particularly important because a valid claim can become uncollectible if it is submitted after the applicable deadline.

For Medicare Fee-for-Service, CMS generally applies a one-year timely filing period from the date the service was furnished, subject to specific rules and exceptions.

A timely filing denial therefore requires immediate investigation of:

• Original submission date
• Clearinghouse acceptance
• Payer receipt
• Rejection history
• Corrected claim history
• Applicable exception
• Proof of timely submission

Never assume that a clearinghouse transmission report alone proves payer adjudication.

How to Perform AR Follow-Up in Medical Billing

A structured AR process is more effective than repeatedly checking the same account.

1. Start With the Oldest or Highest-Risk AR

AR should generally be prioritized using more than age alone.

Consider:

• Days outstanding
• Dollar value
• Filing deadline
• Appeal deadline
• Denial type
• Payer
• Probability of recovery
• Number of previous follow-ups
• Documentation requirements

A $50 claim approaching timely filing may require more urgent action than a $500 claim that is actively pending within normal processing time.

2. Review the Entire Claim History

Before contacting a payer, review:

• Date of service
• Patient information
• Insurance
• Subscriber information
• CPT/HCPCS
• ICD-10-CM diagnosis codes
• Modifiers
• Units
• Charges
• Place of service
• Authorization information
• Claim submission date
• Clearinghouse response
• Payer acknowledgement
• Previous payer responses
• Remittance advice
• Previous appeal activity

This prevents unnecessary calls and repeated mistakes.

3. Determine the Current Claim Status

The account should be classified correctly.

For example:

Submitted but not received

is different from

Received but not processed

which is different from

Processed and denied

and different again from

Processed and underpaid.

Each status requires a different action.

4. Identify the Root Cause

Do not stop at “claim denied.”

Ask why.

For example:

Denial: Missing information

Root cause: Missing authorization number

Verification: Authorization existed in the payer portal

Action: Submit corrected claim with valid authorization information

Another example:

Denial: Medical necessity

Root cause: Payer policy does not support the diagnosis submitted for the service

Action: Review documentation and coding; if documentation supports another diagnosis that was actually established by the provider, follow applicable coding rules and payer correction procedures.

5. Take the Correct Action

Possible actions include:

• Corrected claim
• Documentation submission
• Appeal
• Reconsideration
• Payer inquiry
• Authorization verification
• Eligibility correction
• Secondary claim
• Contractual adjustment
• Patient responsibility transfer when appropriate

6. Record the Follow-Up

Every meaningful AR action should be documented.

A useful note includes:

Date → payer/contact → claim status → denial/reason → action taken → reference number → documents requested/submitted → expected response → next follow-up date

“Called insurance; pending” is often inadequate.

A stronger note would identify what was verified, what remains outstanding, and when the account should be revisited.

7. Escalate When Necessary

Escalation may be appropriate when:

• The payer contradicts its own previous determination
• A high-dollar claim remains unresolved
• A systemic payer issue affects multiple claims
• An appeal deadline is approaching
• Medical records have been submitted but not reviewed
• A contractual underpayment is suspected
• A claim has been repeatedly denied for the same reason

Documentation Checklist for AR Follow-Up

Documentation affects the ability to prove that a claim was submitted correctly, that the service was supported, and that follow-up actions were timely.

Documentation Item	Why It Matters
Date of service	Establishes the encounter and applicable coding/payer period
Provider documentation	Supports the reported clinical service and diagnosis
CPT/HCPCS code	Identifies the billed service
ICD-10-CM code	Supports the documented diagnosis or reason for service
Modifier documentation	Supports applicable modifier reporting
Authorization record	Demonstrates authorization when required
Eligibility verification	Confirms coverage information for the applicable date
Claim submission record	Establishes when and how the claim was submitted
Clearinghouse acceptance/rejection	Helps distinguish transmission problems from payer processing
Payer acknowledgement	Helps establish payer receipt
ERA/EOB	Shows adjudication and adjustment information
Medical records	May support medical necessity or appeal
Appeal documentation	Demonstrates the basis and timing of the appeal
Payer reference number	Provides evidence of contact and status
Follow-up notes	Creates an audit trail of AR activity
Contract/fee schedule information	Helps identify potential underpayments

A good documentation standard allows another knowledgeable employee to open the account and understand its history without repeating the entire investigation.

What Should an AR Follow-Up Note Include?

An AR note should answer five questions:

1. What was reviewed?
2. What did the payer say?
3. Why is the account still unresolved?
4. What action was taken?
5. What happens next?

Example of a weak note

Called payer. Claim pending. Follow up later.

Example of a stronger note

Verified claim received by payer on 08/12/2026. Payer representative confirmed claim remains pending for medical review. Reference number documented. No additional records requested at this time. Follow-up scheduled after payer’s stated processing period.

The second note creates a much better operational record.

How to Prioritize AR Aging

AR aging reports commonly separate outstanding balances by age.

A practice may use categories such as:

These ranges are management conventions, not universal payer rules.

The actual priority should depend on the payer’s processing time, filing deadlines, appeal deadlines, contract terms, dollar value, and denial type.

AR Days vs. Aging: What Is the Difference?

AR aging tells you how long individual balances have remained outstanding.

AR days estimates how many days of revenue are represented by outstanding receivables.

Both metrics are useful, but neither should be viewed in isolation.

For example, AR days can appear healthy while a practice has a serious problem with a particular payer. Conversely, a temporary increase in AR can occur because of seasonal volume or payer processing delays without representing a permanent collection problem.

Providers should also examine:

• Clean claim rate
• Denial rate
• Net collection rate
• Gross collection rate
• Days in AR
• Percentage of AR over 90 days
• Payment variance
• First-pass resolution
• Appeal overturn rate
• Unresolved high-dollar claims

How Should Providers Handle Underpaid Claims?

Not every AR problem is a denial.

A claim may be paid but still contain an incorrect reimbursement amount.

For an underpayment review, compare:

Billed amount → Contracted/expected allowed amount → Payer allowed amount → Payment → Adjustment → Patient responsibility

The provider should then determine whether the difference is:

• Contractual
• Correct patient responsibility
• Bundling
• Multiple-procedure reduction
• Payer policy adjustment
• Incorrect payment
• Incorrect coding
• Incorrect contract configuration

If the payer’s payment does not match the applicable contract or fee schedule, the account may require a payment dispute or other payer-specific process.

AR Follow-Up and Medical Necessity

Medical necessity is one of the areas where AR, coding, clinical documentation, and payer policy intersect.

A medical necessity denial should not automatically trigger a diagnosis-code change.

The correct sequence is:

Review the medical record → Identify the provider-documented diagnosis → Verify coding rules → Review payer coverage policy → Compare billed service with coverage requirements → Determine appropriate correction or appeal

Coders should not independently diagnose a patient based solely on test results, imaging, laboratory findings, or other clinical information when the applicable coding rules require provider documentation.

If the record does not support the billed diagnosis, the appropriate response may involve a provider query or other compliant documentation process rather than simply changing the code.

AR Follow-Up and CPT Coding

CPT codes identify reported medical services and procedures. They can become central to AR investigation when a payer denies or reduces payment because of the service reported.

Common areas requiring review include:

• Evaluation and management services
• Procedures
• Diagnostic services
• Surgery
• Preventive services
• Category II codes
• Category III codes
• Modifiers
• Add-on codes
• Bundled services
• Global surgical package rules

However, there is no universal “AR CPT code.”

The CPT code must describe the service actually provided and documented.

When a payer denies a service because the CPT code does not align with the documentation, the correct approach is to review the original documentation and applicable coding rules. A code should not be selected simply because it is more likely to generate reimbursement.

AR Follow-Up and ICD-10-CM Diagnosis Coding

ICD-10-CM can directly influence medical necessity and claim adjudication.

For example, a payer may have coverage criteria requiring specific diagnosis categories for a service.

During AR follow-up, review whether:

• The diagnosis was documented by the provider
• The reported code accurately reflects that documentation
• The code is sufficiently specific
• Laterality is correctly reported where required
• Acute versus chronic status is supported
• Encounter requirements are satisfied where applicable
• Combination-code requirements were followed
• Excludes and instructional notes were considered
• Sequencing requirements were followed
• The diagnosis supports the billed service under the applicable payer policy

The AR representative should not treat ICD-10-CM as a list of codes to manipulate until a claim pays.

Coding accuracy comes first.

What Are CARCs and RARCs in AR Follow-Up?

CARCs and RARCs are particularly useful for understanding payer adjudication.

Claim Adjustment Reason Code

A CARC identifies the reason for a claim adjustment.

Examples of adjustment situations can include:

• Missing information
• Duplicate claim
• Authorization issue
• Filing deadline
• Noncovered service
• Bundling
• Patient responsibility
• Contractual adjustment

The exact current code description should always be verified against the applicable official code list rather than relying on an old internal spreadsheet.

Remittance Advice Remark Code

A RARC provides additional information about an adjustment or remittance processing.

A RARC can provide detail that helps explain the CARC.

For AR purposes, the important point is:

Do not interpret the CARC without reviewing the associated RARC and the actual payer remittance.

The combination often provides a much clearer explanation of what must happen next.

How to Work a Denied Claim

A practical denial workflow is:

Step 1: Read the denial

Do not rely solely on a denial category in the practice-management system.

Review the actual payer remittance.

Step 2: Identify the denial code

Determine the CARC, RARC, payer-specific message, or other applicable reason.

Step 3: Check the claim

Review the submitted:

• CPT/HCPCS
• ICD-10-CM
• Modifier
• Units
• Provider
• Place of service
• Authorization
• Patient/insurance information

Step 4: Review the documentation

Determine whether the medical record supports what was billed.

Step 5: Check payer policy

Coverage rules differ among Medicare, Medicaid, Medicare Advantage plans, commercial insurers, and other payers.

Step 6: Select the appropriate resolution

The account may need:

• Corrected claim
• Reconsideration
• Appeal
• Medical records
• Authorization information
• Eligibility correction
• Secondary billing
• Contractual adjustment
• Other payer-specific action

Step 7: Track the deadline

A denial without a deadline is not necessarily a safe denial.

Appeal and reconsideration deadlines vary by payer and claim type.

For Medicare Fee-for-Service, the first-level redetermination generally has a 120-day filing period from receipt of the Medicare Summary Notice or Remittance Advice, subject to applicable rules and exceptions.

AR Follow-Up for Medicare Claims

Medicare claims require particular attention to CMS instructions and the applicable Medicare Administrative Contractor.

Providers should verify:

• Claim submission requirements
• Timely filing
• Medicare eligibility
• Secondary payer information
• NCCI edits
• Medical necessity requirements
• National Coverage Determinations
• Local Coverage Determinations
• Documentation requirements
• Appeal rights
• Reopening opportunities
• Corrected claim procedures

CMS guidance is organized through the Medicare Claims Processing Manual and related manuals and instructions.

For Medicare claims, a one-size-fits-all AR process is risky because the appropriate response depends on the claim type, denial, contractor, benefit category, and applicable rule.

What Is the Difference Between a Rejection and a Denial?

This distinction is critical.

Rejection

A rejection generally means the claim did not successfully pass a particular submission or front-end requirement and was returned for correction rather than fully adjudicated as a payable/denied claim.

Examples may include:

• Invalid data
• Missing required information
• Invalid subscriber information
• Formatting issues

The claim may need correction and resubmission.

Denial

A denial generally means the payer adjudicated the claim or service and determined that payment would not be made for the stated reason.

The next step may be:

• Corrected claim
• Reconsideration
• Appeal
• Documentation
• Other payer-specific action

Confusing rejections with denials can distort denial metrics and lead to the wrong workflow.

Common AR Follow-Up Mistakes

Treating every unpaid claim as a denial

An unpaid claim may simply be processing.

Rebilling without checking claim status

Repeated submission can create duplicate claims.

Changing diagnosis codes to overcome denials

Diagnosis coding must reflect provider documentation and applicable coding rules.

Ignoring filing deadlines

A claim that could have been recovered may become uncollectible if the deadline passes.

Failing to document payer calls

Without reference numbers and detailed notes, future follow-up becomes inefficient.

Working accounts strictly by age

A 200-day account is important, but a 25-day account with a filing deadline approaching may be more urgent.

Ignoring underpayments

Paid claims can still represent lost revenue.

Focusing only on individual claims

If 200 claims have the same denial, the organization should investigate the systemic cause rather than work each claim independently forever.

How Technology Can Improve AR Follow-Up

Modern practice-management and revenue cycle systems can help identify accounts requiring action.

Useful capabilities include:

• Automated claim-status checks
• Denial categorization
• AR aging dashboards
• Work queues
• Eligibility verification
• Claim tracking
• Appeal tracking
• Payment variance analysis
• Payer performance reporting
• Automated reminders
• Documentation storage
• Reporting by CPT/HCPCS
• Reporting by ICD-10-CM
• Reporting by payer
• Reporting by provider
• Reporting by location
• Reporting by denial reason

Automation should support—not replace—professional review.

A system that automatically submits corrected claims without understanding why the original claim failed can increase errors instead of reducing them.

AR Follow-Up Metrics Providers Should Monitor

A useful AR dashboard should answer more than “How much money is outstanding?”

Days in AR

Shows the approximate time represented by outstanding receivables.

AR over 90 days

Helps identify older balances that may require escalation.

Denial rate

Shows how frequently claims are denied.

Clean claim rate

Shows how successfully claims pass initial processing requirements.

Net collection rate

Helps evaluate how effectively collectible revenue is being converted into payment.

Appeal overturn rate

Shows how often denied claims are successfully recovered through appeal.

Payer-specific denial rate

Can identify insurers creating recurring problems.

Underpayment rate

Helps identify reimbursement discrepancies.

First-pass resolution

Shows how many claims are resolved without repeated intervention.

Metrics should be analyzed together rather than treated as isolated targets.

Practical AR Follow-Up Example

Consider a clinic that submits a claim for an office visit and an additional procedure.

The claim contains:

• A CPT code representing the office service
• A CPT code representing the procedure
• Appropriate modifier reporting when supported
• ICD-10-CM diagnosis codes documented by the provider

The payer processes the claim but denies one service.

The AR representative should not immediately rebill.

Instead:

Step 1: Review the remittance.

Step 2: Identify the CARC and RARC.

Step 3: Determine whether the payer considered the service bundled.

Step 4: Review the CPT codes and modifiers.

Step 5: Review the documentation.

Step 6: Determine whether the service qualifies for separate reporting under the applicable coding rules.

Step 7: Review payer-specific policy.

Step 8: If the original claim was incorrect, correct it through the appropriate process.

Step 9: If the claim was correctly reported and supported, prepare the appropriate reconsideration or appeal.

Step 10: Record the action, reference number, deadline, and next follow-up date.

This workflow prevents the common mistake of treating every denial as a billing-data problem.

AR Follow-Up Checklist for Providers

Use this checklist when reviewing an unresolved account:

Question	Completed?
Is the patient information correct?	☐
Was eligibility verified for the date of service?	☐
Is the correct payer identified?	☐
Was the claim actually received?	☐
Was the claim rejected or denied?	☐
What is the exact payer reason?	☐
Were the CARC/RARC reviewed?	☐
Are CPT/HCPCS codes accurate?	☐
Are ICD-10-CM codes supported by provider documentation?	☐
Are modifiers supported?	☐
Were units reported correctly?	☐
Was authorization required?	☐
Was authorization obtained?	☐
Does the service meet applicable medical necessity requirements?	☐
Is additional documentation required?	☐
Is the claim within the filing deadline?	☐
Is an appeal or reconsideration deadline approaching?	☐
Does the payment match the expected reimbursement?	☐
Is patient responsibility accurate?	☐
Has the account been documented properly?	☐
Is a follow-up date assigned?	☐
Does the account require escalation?	☐

AR Follow-Up Best Practices for Medical Practices

Build payer-specific workflows

Different payers can have different submission, correction, documentation, and appeal procedures.

Create denial-specific work queues

Separate authorization denials from eligibility, medical necessity, coding, duplicate, and timely filing issues.

Establish escalation thresholds

High-dollar and high-risk accounts should receive faster management.

Track root causes

If a recurring denial affects many claims, identify the upstream problem.

Audit corrected claims

Correction should fix the actual error rather than simply changing claim data.

Monitor payer behavior

Patterns in delayed processing, denials, and underpayments may reveal payer-specific problems.

Protect appeal deadlines

A technically valid appeal has little value if submitted after the applicable deadline.

Keep documentation complete

Every action should leave a traceable account history.

Separate clinical judgment from billing follow-up

AR staff should not independently establish diagnoses or alter clinical documentation.

Measure recovery, not just activity

The number of calls made is less meaningful than appropriate claims resolved and dollars accurately recovered.

How AR Follow-Up Supports the Entire Revenue Cycle

AR follow-up is sometimes treated as the final stage of medical billing, but the information collected during AR activity can improve the entire revenue cycle.

For example:

A payer repeatedly denies a service because authorization information is missing.

The AR team identifies the pattern.

Management discovers that the authorization number is collected during scheduling but not transferred into the claim.

The problem is therefore not simply an AR problem.

It is a workflow problem.

Similarly, repeated medical necessity denials may indicate:

• Documentation gaps
• Incorrect diagnosis selection
• Inadequate payer-policy awareness
• Charge capture issues
• Incorrect order information
• Authorization problems
• Provider documentation deficiencies

Effective AR teams therefore provide feedback upstream.

Conclusion

Effective AR follow-up in medical billing is much more than repeatedly checking claim status. It is a structured process that connects documentation, CPT and HCPCS reporting, ICD-10-CM diagnosis coding, claim submission, payer policies, remittance analysis, denials, appeals, payment accuracy, and financial resolution.

For providers, hospitals, clinics, and healthcare organizations, the strongest AR process asks a simple question at every stage:

Why has this claim not been resolved, and what is the correct next action?

That question helps distinguish a pending claim from a denial, a rejection from an adjudicated claim, a coding problem from a payer-policy issue, and a legitimate patient balance from an amount that should remain with the payer.

There is also an important coding distinction: AR follow-up itself does not have a universal CPT, ICD-10-CM, or DX code. The underlying healthcare service is represented by the appropriate CPT/HCPCS and ICD-10-CM codes, while CARCs and RARCs help explain payer adjustments and remittance outcomes.

When AR follow-up is supported by accurate documentation, compliant coding, timely claim submission, detailed payer research, disciplined denial management, and reliable account notes, providers can reduce preventable delays, improve reimbursement accuracy, protect appeal rights, and create a more defensible revenue cycle.

Ultimately, good AR management is not about chasing every unpaid dollar in the same way. It is about understanding why the balance exists, what the evidence supports, what the payer requires, and what action should happen next.

Frequently Asked Questions About AR Follow-Up in Medical Billing

What is AR follow-up in medical billing?

AR follow-up in medical billing is the process of investigating and resolving unpaid, denied, rejected, underpaid, or otherwise outstanding healthcare claims to obtain appropriate reimbursement or correctly resolve the account.

What does AR stand for in medical billing?

AR stands for accounts receivable. It represents amounts owed to a healthcare provider that have not yet been collected.

Is there an ICD-10 code for accounts receivable?

No. Accounts receivable is a financial and revenue-cycle concept, not a patient diagnosis. ICD-10-CM codes represent documented diagnoses and conditions rather than AR activity.

Is there a CPT code for AR follow-up?

There is no general CPT code specifically representing routine AR follow-up. CPT codes describe medical services and procedures, while payer follow-up is generally an administrative revenue-cycle activity.

What codes are most important during AR follow-up?

The relevant codes can include CPT, HCPCS, ICD-10-CM, modifiers, POS codes, CARCs, and RARCs, depending on the claim and reason for follow-up.

What are AR denials in medical billing?

AR denials are unpaid claim or service determinations that remain unresolved in accounts receivable. They can result from eligibility, authorization, coding, medical necessity, timely filing, duplicate claims, coverage limitations, documentation, and other issues.

How often should AR be followed up?

There is no single universal follow-up interval. The timing should consider the payer’s normal processing period, claim status, filing deadline, appeal deadline, dollar value, and denial type.

What is the difference between AR and denial management?

AR management covers outstanding receivables broadly. Denial management focuses specifically on claims or services that have been denied and the processes required to correct, appeal, prevent, or resolve those denials.

Can a coder change an ICD-10 code to get a claim paid?

Not simply for reimbursement purposes. The code must accurately represent the provider’s documentation and comply with applicable coding rules. A coding change should have a legitimate documentation and coding basis.

What is the most important part of AR follow-up?

The most important step is identifying the actual reason the account remains unresolved and taking the appropriate action before a filing, appeal, or other deadline expires.