Accounts Receivable Billing and Management

Introduction

Accounts receivable billing and management is more than getting bills out the door. For infectious disease practices, it ties together authorization checks, infusion documentation, claim submission, payer remittances, and the cash that actually funds payroll and drug inventory.

Many ID groups learn the hard way that a stalled prior authorization or a missing infusion stop time can tie up thousands of dollars in a single drug claim. Add buy-and-bill economics, OPAT transitions between hospital and clinic, and multiple payer rulebooks, and AR stops being a back-office afterthought.

This guide walks physicians, group leaders, and administrators through the AR billing process end to end, with a US focus. Coding, coverage, authorization, and payer requirements change often, so verify specifics against current CMS guidance and your own payer contracts before acting.

Key Takeaways

• AR is money owed for services already delivered, not yet collected, spanning payer and patient balances
• Documentation, charge capture, claims, denials, and payment posting function as one connected revenue cycle
• Prioritize fixes using your own aging, payer, and denial data instead of generic industry benchmarks
• The goal is accurate, compliant collection that protects patient and referral relationships, not just speed

What Is Accounts Receivable Billing and Management?

Accounts receivable (AR) billing is the process of recording what a practice is owed, getting that claim or invoice in front of the right payer or patient, and following it through to payment.

The core steps look like this:

• Record the charge - link the encounter to the correct codes, units, and provider
• Submit the claim or invoice - send it to the payer or bill the patient directly
• Track the balance - monitor status until it's resolved
• Collect payment - from the payer, the patient, or both
• Post the remittance - match what came in to what was billed
• Resolve what's left - correct, appeal, or write off disputed amounts

A claim creates an AR entry. It doesn't create cash. That distinction matters more in infectious disease billing than almost anywhere else: a $4,000 infusion claim sitting in AR for 60 days is revenue the practice has already spent on drug inventory, nursing time, and overhead, but hasn't actually received.

Medical AR also carries more moving parts than a typical commercial invoice. A standard vendor invoice just says "pay this by this date." A medical claim depends on several links in sequence:

• Eligibility checks and prior authorization
• Clinical documentation, plus diagnosis and procedure coding
• Payer-specific claim edits and adjudication rules
• Remittance advice, contractual write-offs, and any remaining patient balance

Any one of those links can break and stall the whole chain.

Accounts Receivable vs. Accounts Payable

AR and accounts payable (AP) sit on opposite sides of the same ledger.

• AR is money owed to the practice, by payers or patients, for services already delivered
• AP is money the practice owes to others, such as laboratories, infusion supply vendors, landlords, or staff

AR expected to be collected within the normal operating cycle is generally treated as a current asset, while AP due in that same period is a current liability. That's an accounting classification, not a guarantee of cash in hand.

A simple example: an unpaid infectious disease consultation claim sitting with a commercial payer is AR. An unpaid invoice from a reference laboratory for culture work is AP. Both affect cash flow, but they're opposite entries.

The Accounts Receivable Billing Process: Step by Step

Six stages carry a claim from the first phone call to final reconciliation.

Confirm Coverage Before the Encounter

Before or at the time of care, confirm patient demographics, responsible party, insurance eligibility, referral or prior authorization requirements, and the specific service line involved, whether that's a consult, infusion, or OPAT episode.

For drug-heavy specialties, a practical habit is building a one-page criteria sheet per drug, per payer, covering authorization requirements, clinical criteria, submission channel, and expected turnaround. It turns authorization from guesswork into a checklist.

Capture the Service and Submit the Claim

Connect the clinical encounter to the billable event: diagnosis codes, procedure codes, units, supplies, and the treating provider. OPAT, infusion, and buy-and-bill workflows deserve extra scrutiny, since drug units, infusion hierarchy, and start and stop times all affect payment.

Claims typically go out electronically using the 837P professional format, with the CMS-1500 reserved for exceptions. Getting this right means checking codes, modifiers, place of service, payer IDs, and required attachments against CMS's billing guide and current payer policy.

Process Payer Responses

Remittance advice shows what happened: paid, adjusted, or denied, with reason and remark codes attached. Not every rejection is a denial. A claim returned as "unprocessable" because of missing or invalid information has no appeal rights. It needs correction and resubmission, not an appeal letter.

Post Payments and Follow Up

Match every payer and patient payment to the right account and claim. Record contractual adjustments and approved write-offs per policy, reconcile deposits against the billing system and general ledger, and chase unapplied cash before it goes invisible.

A working follow-up queue needs:

• One named owner and one named backup
• Daily review of anything past its target resolution date
• A defined escalation path, including peer-to-peer review for stuck authorizations

A compact example: A patient starts OPAT after hospital discharge. The practice confirms authorization and vascular access before the first dose, documents infusion start and stop times, bills drug and administration separately, and tracks the claim through remittance.

If the payer denies for an expired authorization mid-course, the biller flags it same-day, requests an extension citing the original approval, and resubmits. The account closes only once payment posts and reconciles to the deposit.

Managing AR in an Independent Infectious Disease Practice

Good AR management requires written policies that staff follow consistently.

Build Policies Staff Can Follow

Document expectations for:

• Payer verification and authorization checks
• Charge-entry responsibilities and timelines
• Claim-submission deadlines
• Denial ownership and escalation thresholds
• Patient statements, payment plans, and refunds
• Write-off and appeal criteria

Segment the Ledger

Lumping all outstanding AR together hides the real problem. Break it down by payer, aging bucket, provider, service line, denial reason, and dollar value.

AR over 90 days, segmented by payer and drug, often tells you more in five minutes than a month of total-collections reporting. Concentration in one drug or payer usually points to a specific authorization or coding problem, not a broad collections failure.

Share accountability, too. Physicians, coders, billers, administrators, and any outsourced billing partner all hold pieces of the AR puzzle, and documentation gaps need a shared channel, not siloed complaints after the fact.

Collect without damaging relationships: communicate clearly to prevent most disputes, resolve legitimate issues before escalating, and document every outreach attempt while staying within applicable collection law and contract terms.

Finally, reconcile routinely: compare billing-system activity, remittance advice, bank deposits, and the general ledger on a set schedule. Limit PHI access to roles that need it, especially if billing is outsourced.

Use Your Practice's Numbers to Prioritize Action

Skip generalized industry benchmarks. Map your own open AR by payer and service line, denial categories and dollar impact, payer mix, staff time on follow-up, and collection costs.

GrowInfectiousDisease publishes free, ungated, browser-based tools, including the Independent ID Practice Economics Calculator, built for this kind of modeling. Nothing you enter is transmitted or stored, and no email is required to see a result. Use your own verified figures, not the illustrative defaults, and review output with your financial or compliance advisor.

Then build a short action plan:

1. Pick the single largest avoidable delay
2. Assign one owner
3. Set a review period
4. Test one process change
5. Check whether that AR category actually improves

Medical Billing Considerations for Infectious Disease Practices

Not every ID service follows the same reimbursement path. Office consultations, inpatient follow-up, OPAT oversight, infusion services, and drug billing each carry distinct authorization rules, documentation needs, and payment timing. Treating them as one workflow is a common source of avoidable AR aging.

Documentation Drives Collectability

Missing dates, diagnoses, orders, duration, units, or supervising-provider details can stall a claim before a payer even looks at medical necessity.

Infusion and injection services follow a specific hierarchy of initial, subsequent, and sequential codes. Payers expect documented start and stop times to support time-based billing, along with volume and rate data when requested, per CMS's infusion billing article.

A missed reauthorization before an antimicrobial approval expires can also create a mid-course coverage gap, turning weeks of administered drug into a denial.

Coordinate Across Organizations

An ID practice rarely works alone. Hospitals, infusion providers, home-health agencies, laboratories, pharmacies, and billing vendors all touch the same episode of care.

Without clear handoffs, you get duplicate billing, missing records, or an OPAT episode that silently exports to someone else's billing system. Deciding, in writing, who owns the discharge antimicrobial plan and who bills for it prevents a lot of aging AR.

Medicare, Medicare Advantage, Medicaid, and commercial plans also differ on authorization, timely filing, and appeals. Always verify current requirements against the specific payer's policy rather than assuming one rule applies everywhere.

To investigate an aging balance without exposing unnecessary PHI:

1. Check claim status and remittance details first
2. Confirm the claim reached the correct payer
3. Look for documentation or authorization gaps
4. Decide whether a corrected claim or a formal appeal applies
5. Document the resolution

Common AR Breakdowns and How to Diagnose Them

Most aging AR traces back to a handful of repeat offenders:

• Front-end errors - eligibility, demographics, coordination-of-benefits mistakes
• Charge-entry delays - consults performed but never entered
• Coding or documentation gaps - missing infusion times, mismatched drug units
• Claim rejections - unprocessable submissions needing correction, not appeal
• Payer denials - medical necessity, bundling, authorization-absent
• Underpayments - incorrect fee schedules or NDC mismatches

Separate preventable process failures from legitimate payer decisions or genuine patient inability to pay. Judging staff purely on total collections, without examining root cause, punishes people for problems they didn't create. Review recurring denial and aging patterns monthly, and assign the fix to whichever process step actually caused it.

AR KPIs and a Practical Improvement Plan

A handful of measures, pulled from your own data, show where AR management is working and where it isn't.

• Days in AR - current receivables divided by average daily charges; define gross versus net before comparing periods, per MGMA's KPI guidance
• AR over 90 days (%) - shows where authorization and drug-claim problems accumulate
• Clean-claim/first-pass rate - claims paid without manual rework
• Denial rate, measured in dollars - count-based rates understate infusion exposure
• Denial overturn/appeal success - how often appeals actually recover money
• Net collection rate - payments collected against what you were entitled to
• Payment-posting lag, unapplied cash, and patient-balance trends - lag and unapplied cash that delay recognition of what you already collected

Define each measure's formula, data source, and review frequency for your own practice. Generic benchmark numbers deserve caution, since definitions and denominators vary by source.

Segment Before You Celebrate

A healthy overall collection rate can hide a serious problem. One denied biologic, unpaid for 90 days, can outweigh a month of office-visit revenue in a drug-heavy practice. Segment every KPI by payer and service line before drawing conclusions. A 92% collection rate across the whole practice means little if your OPAT line is running at 60%.

Review cadence that works:

• Daily: work queues for urgent claims, denials, and authorization expirations
• Weekly: ownership review of aging accounts, with named escalation
• Monthly: leadership review of trends, root causes, and assigned fixes

Before changing a workflow, run this short sequence:

1. Confirm the underlying data is accurate
2. Identify the earliest point of failure, not just the symptom
3. Estimate staff and compliance impact
4. Test the change on a small scale, document the result, and revise if the metric does not move

That is the same discipline Persistex applies in a revenue-cycle review: start from the practice's actual payment and denial data, not assumptions.

Conclusion

Accounts receivable billing and management isn't one task. It's a coordinated system. Weaken one link, and the whole chain slows, usually at the expense of cash on work your practice has already delivered.

Core links include:

• Clinical documentation and accurate coding
• Claim submission and denial follow-up
• Patient communication and payment posting
• Financial reconciliation

The fastest path to improvement isn't a generic benchmark. It's your own aging report, your own denial categories, and your own payer mix, reviewed often enough to catch problems before they become write-offs.

GrowInfectiousDisease's free resource hub covers revenue-cycle management, OPAT and infusion economics, and practice sustainability in plain English, with browser-based tools you can run using your own numbers. Start there, verify specifics against current payer and CMS guidance, and build your action plan from what your data actually shows.

Frequently Asked Questions

How do accounts receivable work?

A practice records what it's owed, submits claims or invoices, tracks payer and patient responses, posts payments and adjustments, follows up on unpaid balances, and reconciles the cash that actually arrives.

Are accounts receivable the same as accounts payable?

No. AR is money owed to the practice by payers or patients; AP is money the practice owes to vendors, labs, or staff. AR is typically a current asset, while AP is typically a current liability.

What is accounts receivable medical billing?

It's the full workflow from eligibility verification and clinical documentation through coding, claim submission, payer adjudication, payment posting, denial management, patient billing, and reconciliation.

What are the 7 most important KPIs in medical billing?

Commonly tracked measures include days in AR, AR over 90 days, clean-claim rate, dollar-based denial rate, denial overturn rate, net collection rate, and payment-posting lag. Define, segment, and benchmark each against your own verified data.

What are the 5 C's of accounts receivable management?

The term most often traces to the credit-industry "Five Cs of Credit": character, capacity, capital, collateral, and conditions. It's a credit-risk framework, not an official medical-billing standard, so terminology can vary by source.

Are bills receivable in a balance sheet?

Yes. Unpaid amounts owed to a practice are generally presented as accounts receivable, typically a current asset when collection is expected within the normal operating cycle, subject to the practice's accounting policies.