Medical practices often focus heavily on denied claims because denials are visible and usually require immediate attention.
But there is another revenue problem that can be much harder to notice:
The claim was paid but it was not paid correctly.
This is known as an underpayment.
An insurance company may process a claim and issue a payment, yet the amount received may be lower than the amount the practice expected under the applicable contract, fee schedule, or payment arrangement.
Because money has still been received, an underpayment can easily be overlooked.
Consider a simple example.
A medical practice expects $200 in reimbursement for a covered service based on its applicable payer agreement. The claim is processed, but the practice receives $160.
The claim may appear to be successfully completed because there was no denial.
However, there is a $40 difference that may need to be investigated.
One $40 discrepancy may not seem significant.
But imagine hundreds of similar discrepancies occurring throughout the year.
The cumulative impact can become meaningful.
This is why medical billing underpayments deserve attention as part of a practice’s overall revenue cycle management strategy.
CMS explains that an Electronic Remittance Advice (ERA) provides information about claim payments and adjustments, including adjustments related to contract agreements, benefit coverage, secondary payers, copays, and coinsurance.
For medical practices, carefully reviewing that information can help distinguish between an expected contractual adjustment and a payment that may require further investigation.
Table of Contents
- Introduction
- What Is a Medical Billing Underpayment?
- Why Do Medical Billing Underpayments Happen?
- How Underpayments Affect Medical Practice Revenue
- Common Types of Payment Discrepancies
- The Role of ERA in Identifying Underpayments
- How to Identify Medical Billing Underpayments
- How Underpayment Recovery Works
- Why Contract Knowledge Matters
- Common Underpayment Recovery Challenges
- How Medical Practices Can Prevent Underpayments
- Key Metrics to Monitor
- How Technology Can Improve Payment Accuracy
- When Should a Practice Consider Outsourcing?
- Frequently Asked Questions
- Final Thoughts
- Request a Free Revenue Assessment
What Is a Medical Billing Underpayment?
A medical billing underpayment occurs when a healthcare provider receives less reimbursement than it believes should have been paid for a claim based on the applicable payment terms, contract, fee schedule, or other relevant requirements.
An underpayment is different from a denial.
Denial
A payer does not pay some or all of a claim and provides a reason for the nonpayment.
Underpayment
A payer issues a payment, but the amount may be less than the amount the provider expected to receive.
Correct Contractual Adjustment
A payer reduces the billed charge according to the provider’s contract or applicable reimbursement rules.
This distinction is important.
A lower payment does not automatically mean the payer underpaid the claim.
For example, a provider may bill $300 but have a contractual allowed amount of $180. If the payer pays the appropriate amount according to the contract and applicable patient responsibility, the $120 difference may be a legitimate contractual adjustment.
The purpose of underpayment analysis is therefore not simply to compare the billed amount with the paid amount.
It is to determine whether the payment matches the amount that should have been paid.
Why Do Medical Billing Underpayments Happen?
Underpayments can occur for different reasons.
Some are related to payer processing. Others may involve contract interpretation, coding, claim configuration, or provider data.
1. Incorrect Contractual Reimbursement
The payment may not match the reimbursement terms that apply to the provider.
2. Incorrect Fee Schedule Application
A payer may apply a reimbursement amount that differs from the expected fee schedule.
3. Incorrect Coding
A code may have been processed differently from what the practice expected.
4. Modifier Issues
A modifier can affect how a service is processed and reimbursed.
5. Multiple Procedure Payment Rules
When multiple procedures are performed during the same encounter, payer payment methodologies may affect reimbursement.
6. Bundling
Certain services may be considered included in another service under applicable payer rules.
7. Incorrect Provider Information
Provider identifiers, taxonomy information, location details, or enrollment information can sometimes affect claim processing.
8. Contract Changes
A payer contract or reimbursement arrangement may change, making older payment expectations inaccurate.
9. Patient Responsibility
A portion of the allowed amount may properly be assigned to the patient through deductible, copayment, or coinsurance.
10. Processing Errors
In some cases, the payer’s processing may not align with the applicable payment terms.
The key is to investigate the reason for the difference before assuming that every payment variance represents recoverable money.
How Underpayments Affect Medical Practice Revenue
Underpayments can have a direct impact on a practice’s financial performance.
Suppose a practice receives 1,000 insurance payments during a month.
If just 5% of those payments contain an average $30 payment variance, the potential difference would be:
50 claims × $30 = $1,500
Over 12 months, that could represent:
$18,000
This is only an illustrative example not a prediction of what a particular practice will recover.
The actual impact depends on claim volume, payer mix, reimbursement arrangements, specialties, services, and the frequency and size of payment discrepancies.
Still, the example illustrates an important principle:
Small payment discrepancies can become significant when they occur repeatedly.
Underpayments can also create secondary operational problems.
They may contribute to:
- Lower-than-expected collections
- Increased accounts receivable
- More payment research
- Additional payer follow-up
- Increased billing workload
- Difficulty forecasting revenue
- Missed contractual opportunities
- Reduced visibility into payer performance
A practice can therefore have a relatively strong claim acceptance rate while still leaving revenue unrecognized if payment reconciliation is incomplete.
The Role of ERA in Identifying Underpayments
An Electronic Remittance Advice (ERA) is one of the most useful resources for payment reconciliation.
CMS describes an ERA as an explanation from a health plan to a provider about a claim payment. It explains how claim charges were adjusted based on factors such as contract agreements, secondary payers, benefit coverage, copayments, and coinsurance.
ERAs also use standardized adjustment codes.
CMS explains that Claims Adjustment Reason Codes (CARCs) and Remittance Advice Remark Codes (RARCs) are used to explain claim-payment adjustments.
This information can help billing teams answer questions such as:
- How much did the payer allow?
- How much did the payer pay?
- How much was assigned to patient responsibility?
- What adjustment was applied?
- What reason was given for the adjustment?
- Was the payment consistent with the expected reimbursement?
CMS also notes that electronic remittance advice can allow payment and adjustment information to be automatically posted to billing or accounting applications, reducing manual posting work.
That can make automated reconciliation an important part of an efficient revenue cycle.
How to Identify Medical Billing Underpayments
Identifying underpayments requires more than looking at the amount deposited into the bank account.
A structured process is useful.
Step 1: Review the ERA
Start with the remittance advice.
Identify:
- Allowed amount
- Paid amount
- Adjustments
- Patient responsibility
- Adjustment codes
- Remark codes
- Provider-level adjustments
Step 2: Compare the Payment With Expected Reimbursement
The billing team needs a reliable reference for what should have been paid.
That may involve:
- Payer contract
- Fee schedule
- Reimbursement schedule
- Applicable payment methodology
- Service-specific terms
Step 3: Investigate the Difference
If the actual payment does not match the expected amount, determine why.
Ask:
- Was the correct contract applied?
- Was the claim coded correctly?
- Was the service bundled?
- Was a modifier processed correctly?
- Was patient responsibility calculated correctly?
- Was the provider properly enrolled?
- Did the payer apply an adjustment code explaining the difference?
Step 4: Determine Whether Recovery Is Appropriate
Not every variance should be appealed.
If the payment matches the applicable contractual terms, the difference may be legitimate.
If the payment appears inconsistent with the applicable reimbursement terms, the account may warrant additional research, correction, or payer follow-up.
Step 5: Document the Finding
Maintain a record of:
- Claim number
- Date of service
- Payer
- Expected payment
- Actual payment
- Variance
- Reason for variance
- Follow-up action
- Resolution
This creates a useful audit trail.
How Underpayment Recovery Works
Underpayment recovery is the process of identifying potentially incorrect payments, investigating the discrepancy, and pursuing additional reimbursement when appropriate.
A typical workflow may look like this:
Payment Received → ERA Reviewed → Expected Payment Calculated → Variance Identified → Root Cause Investigated → Payer Contact/Appeal → Additional Payment or Resolution
The specific process depends on the payer and the circumstances.
Step 1: Identify the Variance
The practice determines that the actual payment differs from the expected reimbursement.
Step 2: Validate the Expected Amount
The billing team checks the applicable contract, fee schedule, or reimbursement terms.
Step 3: Review Claim Details
The team examines:
- CPT/HCPCS codes
- Modifiers
- Units
- Diagnosis codes
- Provider information
- Place of service
- Payer information
Step 4: Review the Remittance
CARCs and RARCs may help explain how the payer processed the claim.
Step 5: Contact or Appeal to the Payer
If the payment appears incorrect, the practice may follow the payer’s applicable dispute, reconsideration, or appeal process.
Step 6: Track the Outcome
Any additional payment should be recorded and reconciled.
The process should also identify whether the same problem is occurring on other claims.
Why Contract Knowledge Matters
One of the biggest challenges in underpayment analysis is knowing what the payer should have paid.
A practice cannot reliably identify an underpayment without an appropriate benchmark.
That benchmark may come from:
- Provider contracts
- Fee schedules
- Payer amendments
- Specialty-specific reimbursement terms
- State or federal requirements where applicable
- Other applicable payment arrangements
This is why contract management and credentialing can have a relationship with revenue cycle performance.
If a provider’s payer participation information is outdated or a reimbursement agreement is not properly tracked, the billing team may have difficulty determining whether a payment is correct.
For practices that need assistance with payer enrollment and contract-related administrative work, Mediora Solutions provides Credentialing & Contracting services.
Common Underpayment Recovery Challenges
Challenge 1: High Claim Volume
Reviewing every payment manually can require substantial staff time.
Challenge 2: Complex Payer Contracts
Reimbursement terms can vary by payer, plan, specialty, service, location, and provider.
Challenge 3: Changing Payment Rules
Practices need processes for identifying relevant changes to reimbursement arrangements.
Challenge 4: Small Payment Variances
A $5 or $10 variance may not appear important individually, but repeated discrepancies can accumulate.
Challenge 5: Lack of Resources
Small practices may not have dedicated staff for payment variance analysis.
Challenge 6: Incomplete Documentation
Without clear records, it can be difficult to explain why a payment was considered incorrect or what follow-up occurred.
Challenge 7: Confusing Legitimate Adjustments With Underpayments
A lower payment is not automatically an error.
This is perhaps one of the most important points in payment reconciliation.
The practice needs to understand the payer’s adjustment before deciding that money is actually missing.
How Medical Practices Can Prevent Underpayments
Underpayment recovery is valuable, but prevention is even better.
Maintain Accurate Payer Contracts
Keep current copies of applicable agreements, amendments, and reimbursement schedules.
Maintain Accurate Provider Information
Ensure provider enrollment and payer participation information remains current.
Standardize Payment Posting
Create a consistent process for recording:
- Charges
- Payments
- Adjustments
- Patient responsibility
- Payer information
Review ERAs Carefully
Don’t simply post the payment and move on.
Review the adjustment information when appropriate.
Automate Where Practical
Use technology to compare expected and actual payments when the practice’s systems support this capability.
Monitor Payer Trends
If one payer repeatedly produces payment discrepancies for the same services, investigate the pattern.
Establish Escalation Procedures
Staff should know when a variance should be researched, appealed, escalated, or written off.
Payment Posting vs. Underpayment Analysis
These two activities are related but different.
Payment Posting
Payment posting records the payment and adjustments received from the payer.
Underpayment Analysis
Underpayment analysis compares the actual payment with the expected reimbursement and investigates meaningful differences.
A practice can have accurate payment posting but still fail to identify underpayments.
For example:
Claim billed: $500
Contractual adjustment: $250
Expected payer payment: $200
Actual payer payment: $150
If the $150 payment is posted correctly but nobody compares it with the expected $200, the $50 variance may remain unnoticed.
This is why payment posting and payment reconciliation should work together.
How Technology Can Improve Payment Reconciliation
Technology can make underpayment analysis more scalable.
Depending on the practice’s systems, technology may help with:
- ERA processing
- Automatic payment posting
- Contract modeling
- Expected reimbursement calculations
- Variance identification
- Claim tracking
- Reporting
- Payer trend analysis
- Work queues
CMS notes that ERA data can be automatically posted to accounting or billing applications, which can reduce the time and cost associated with manual posting.
Automation can help identify potential discrepancies, but human review remains important.
A system may flag a variance without understanding the full context of a contract, payer policy, patient responsibility, or coding situation.
The best workflow often combines automation for detection with trained staff for investigation.
Key Metrics to Monitor
Medical practices can track several metrics to understand payment performance.
Underpayment Rate
Measures the percentage of reviewed payments identified as potential underpayments.
Average Underpayment Amount
Shows the average dollar difference per identified variance.
Underpayment Recovery Rate
Measures how much of the identified recoverable amount is ultimately collected.
Recovery Aging
Tracks how long identified underpayments remain unresolved.
Payer Variance Rate
Shows which payers generate the most payment discrepancies.
Service-Level Variance
Identifies services that frequently produce payment differences.
Contract Variance
Tracks discrepancies associated with specific reimbursement arrangements.
The exact definitions should be standardized within the practice so that the metrics remain meaningful over time.
When Should a Practice Consider Outsourcing?
A practice may consider outside support when:
- Payment volume is increasing
- Billing staff are overwhelmed
- A/R is growing
- Payment discrepancies are not being reviewed
- Payer contracts are difficult to track
- Staff spend too much time on manual reconciliation
- Revenue performance is difficult to analyze
- There is no dedicated underpayment recovery team
Outsourcing does not necessarily mean handing over the entire revenue cycle.
A practice may choose support for specific areas such as:
- Payment posting
- A/R follow-up
- Denial management
- Underpayment analysis
- Claims follow-up
- Insurance verification
- Prior authorization
- Credentialing
Mediora Solutions provides Medical Billing services that can support broader revenue cycle activities.
Practices needing additional administrative capacity can also explore Virtual Assistant services.
For authorization-related administrative work, Prior Authorization services can help support the authorization workflow.
And practices that need payer enrollment or contracting support can explore Credentialing & Contracting services.
Frequently Asked Questions
Final Thoughts
Medical billing underpayments can be easy to overlook because the claim was technically paid.
But receiving a payment does not automatically mean the payment was correct.
A strong revenue cycle process should therefore look beyond claim acceptance and denial rates.
It should also ask:
Was the claim paid according to the applicable reimbursement terms?
That question requires accurate payment posting, reliable contract information, careful ERA review, appropriate benchmarks, and consistent follow-up.
CMS’s ERA guidance shows how remittance advice provides detailed information about payment adjustments, including adjustment reason codes and provider-level adjustments.
For medical practices, the process can be summarized simply:
Bill → Receive Payment → Review ERA → Compare Expected vs. Actual → Identify Variance → Investigate → Recover When Appropriate → Monitor the Trend
The objective is not to challenge every payment.
The objective is to make sure the practice understands why it was paid what it was paid.
When underpayments are identified consistently, practices can improve revenue visibility, uncover recurring payer issues, strengthen contract oversight, and potentially recover revenue that might otherwise remain unnoticed.
A well-managed revenue cycle doesn’t stop when the payment arrives.
It starts asking questions about that payment.
Request a Free Revenue Assessment
Are you receiving payments from insurance companies but unsure whether you’re being reimbursed according to your applicable payment terms?
Mediora Solutions can help your practice strengthen its revenue cycle through Medical Billing, payment follow-up, denial management, Virtual Assistant support, Prior Authorization, and Credentialing & Contracting services.
Let our team help you identify opportunities to improve your billing workflow and revenue visibility.
Request a Free Revenue Assessment today and take the next step toward a more organized and efficient revenue cycle.
Book a Free Consultation with Mediora Solutions today.
You can also visit Contact Us to discuss your practice’s revenue cycle needs.