10 Common Therapy Billing Mistakes (And How to Avoid Them)

Overview

10 Common Therapy Billing Mistakes (And How to Avoid Them)

Billing mistakes cost mental health practices thousands of dollars annually in denied claims, delayed payments, compliance penalties, and recoupment demands. Many of these errors are entirely preventable with the right systems and knowledge.

Key takeaways

• 10 Common Therapy Billing Mistakes (And How to Avoid Them) Billing mistakes cost mental health practices thousands of dollars annually in denied claims, delayed payments, compliance penalties, and recoupment demands.
• Many of these errors are entirely preventable with the right systems and knowledge.
• This guide covers the most common billing mistakes we see in therapy practices, why they happen, and exactly how to prevent them.
• The Cost of Billing Errors Before diving into specific mistakes, let's understand the stakes.
• Financial impact of billing errors: Average claim denial rate in behavioral health: 10-20% Cost to rework a denied claim: $25-50 per claim Lost revenue from claims never resubmitted: up to 50% of denials Audit recoupment demands: can reach tens of thousands Timely filing write-offs: permanent revenue loss Beyond finances: Staff time spent on corrections Cash flow disruptions Payer relationship damage Compliance and legal risk Practice reputation concerns The good news: Most billing errors follow predictable patterns.

Details

This guide covers the most common billing mistakes we see in therapy practices, why they happen, and exactly how to prevent them.

The Cost of Billing Errors

Before diving into specific mistakes, let's understand the stakes.

Financial impact of billing errors:Average claim denial rate in behavioral health: 10-20%Cost to rework a denied claim: $25-50 per claimLost revenue from claims never resubmitted: up to 50% of denialsAudit recoupment demands: can reach tens of thousandsTimely filing write-offs: permanent revenue loss

Beyond finances:Staff time spent on correctionsCash flow disruptionsPayer relationship damageCompliance and legal riskPractice reputation concerns

The good news: Most billing errors follow predictable patterns. Address these systematically and you'll significantly improve revenue capture and reduce administrative burden.

Mistake #1: Incorrect CPT Code Selection

What Goes Wrong

Selecting the wrong CPT code is one of the most common billing errors, typically resulting from:Not understanding code definitionsDefaulting to the same code regardless of serviceUnder-coding (fear of audits leading to leaving money on the table)Over-coding (leading to denials and audit risk)Using outdated codes

Common Scenarios

Under-coding: Billing 90834 (38-52 minutes) when the session was actually 55 minutes and should be 90837 (53+ minutes).

Over-coding: Billing 90837 for every session regardless of actual time, triggering payer scrutiny.

Wrong code category: Billing 90834 for a family session that should be 90847, or billing individual therapy codes for group therapy.

Outdated codes: Using codes that have been deleted or replaced in annual CPT updates.

How to Prevent It

Know your codes thoroughly.

Review our comprehensive CPT codes guide and ensure every clinician understands:Time requirements for each codeWhat counts toward face-to-face timeWhen add-on codes applyFamily vs. individual vs. group distinctions

Document time accurately.

Record actual start and stop times for every session. "48 minutes face-to-face" is better than "approximately 45 minutes."

Build code selection into workflow.

Your EHR should prompt for time and suggest appropriate codes rather than requiring clinicians to remember code ranges.

Audit your own coding.

Quarterly, review a sample of claims to verify codes match documentation. Look for patterns (always billing 90834? Check if some should be 90837 or 90832).

Mistake #2: Missing or Incomplete Documentation

What Goes Wrong

Claims require supporting documentation. When documentation is missing, incomplete, or doesn't match the service billed, claims get denied or—worse—payments get recouped after audit.

Common Scenarios

Missing treatment plan: Billing ongoing services without a documented treatment plan with measurable goals.

No medical necessity: Documentation doesn't establish why services are medically necessary.

Time not documented: Session time not recorded, making time-based codes unsupportable.

Signature or date missing: Basic requirements not met.

Copy-paste notes: Notes so generic they could apply to anyone, triggering audit concerns.

How to Prevent It

Understand payer documentation requirements.

Different payers have different standards. Medicare, Medicaid, and commercial plans each have specific requirements. Know what your major payers require.

Create documentation templates that prompt compliance.

Templates should include required fields:Session date and timeDuration (actual start/stop preferred)Diagnosis codeTreatment goals addressedInterventions usedPatient responseNext stepsSignature and credentials

For complete documentation guidance, see our SOAP notes guide.

Complete documentation timely.

Same-day documentation is most accurate. Within 24-48 hours is standard. Documentation completed weeks later is more likely to be incorrect and less defensible in audits.

Conduct regular chart audits.

Review a sample of records monthly for documentation completeness. Address patterns with individual clinicians.

Mistake #3: Timely Filing Failures

What Goes Wrong

Every payer has a deadline for claim submission—miss it, and the claim is permanently denied with no recourse.

Common timely filing limits:

Common Scenarios

Claims sitting unsubmitted: Services provided but claims not filed due to system issues, staffing gaps, or workflow breakdowns.

Incorrect initial submission: Claim denied, corrected claim exceeds timely filing by the time it's resubmitted.

Insurance discovery delay: Patient's correct insurance not identified until after filing deadline.

Authorization obtained late: Needed prior auth not secured; services provided; by time authorization issue resolved, filing deadline passed.

How to Prevent It

Know your payer deadlines.

Create a reference document listing filing deadlines for every payer you bill.

Submit claims within days, not weeks.

Best practice: submit claims within 24-48 hours of service. This maximizes time to address any denial.

Track claim status systematically.

Your practice management system should show claims aging. Review weekly:Claims approaching filing deadlineDenied claims requiring resubmissionClaims with no response

Set calendar reminders for deadlines.

For any claim that's stuck, set a reminder well before the deadline.

Document timely filing exceptions.

Some payers allow extensions for claim correction. Document all communications about deadline extensions.

Mistake #4: Eligibility and Authorization Failures

What Goes Wrong

Providing services without verifying eligibility or obtaining required authorization leads to preventable denials.

Common Scenarios

Insurance terminated: Client's coverage ended but practice wasn't aware.

Wrong insurance billed: Client has multiple coverages; claim sent to wrong payer.

Prior authorization required: Services provided without required authorization.

Authorization expired: Sessions provided after authorized visits or dates exhausted.

Out of network: Services billed as in-network when actually out of network.

How to Prevent It

Verify eligibility before every service.

Yes, every service. Electronic eligibility verification takes seconds and prevents costly denials.

Know what requires authorization.

Create a reference guide for each major payer: what services require prior auth, how many sessions are typically authorized, and authorization timelines.

See our detailed prior authorization guide for comprehensive strategies.

Track authorizations systematically.

Your system should:Store authorization numbersTrack approved vs. used sessionsAlert when authorization is expiringFlag when reauthorization needed

Document all eligibility verifications.

Record confirmation numbers, dates verified, and verified benefits. This creates evidence if disputes arise.

Mistake #5: Incorrect Patient Information

What Goes Wrong

Simple errors in patient demographic information cause claim denials—often for claims that would otherwise be paid.

Common Scenarios

Name mismatch: Patient goes by middle name but insurance uses legal first name.

Date of birth error: One digit off = claim denied.

Policy number typos: Claim rejected at payer.

Address outdated: Claim returned; patient correspondence fails.

Subscriber vs. patient confusion: For dependent coverage, mixing up policyholder and patient information.

How to Prevent It

Verify information directly from insurance card.

Don't rely on patient memory—copy information directly from their current card.

Confirm at every visit.

Build verification into check-in: "Is your name, date of birth, and insurance information still the same?"

Double-entry verification.

For new patients, have two staff members verify critical fields independently.

Standardize data entry.

Consistent formats (date of birth, address, phone) reduce errors.

Use eligibility verification to catch errors.

Electronic eligibility checks will flag name/DOB mismatches before claims are submitted.

Mistake #6: Diagnosis Coding Errors

What Goes Wrong

ICD-10 diagnosis codes must support the services billed. Errors lead to denials and compliance risk.

Common Scenarios

Non-covered diagnosis: Billing a diagnosis the payer doesn't cover (adjustment disorders under some plans, V-codes, etc.).

Specificity insufficient: Using unspecified codes when more specific codes are available and clinically appropriate.

Diagnosis doesn't match service: Family therapy billed with a diagnosis code that doesn't justify family involvement.

Outdated codes: Using ICD-9 codes or deleted ICD-10 codes.

Primary/secondary order incorrect: Some payers require specific primary diagnosis assignment.

How to Prevent It

Code to the highest specificity supported by documentation.

"Major depressive disorder, single episode, moderate" (F32.1) is better than "Depressive disorder, unspecified" (F32.9) if documentation supports it.

Verify diagnosis coverage.

Know which diagnoses your major payers cover. Some exclude:V/Z codes (psychosocial circumstances)Adjustment disordersCertain developmental conditions

Update codes annually.

ICD-10 codes are updated each October. Review changes that affect behavioral health.

Link diagnosis to service logically.

Ensure the diagnosis justifies the service. Anxiety diagnosis with family therapy? Document why family involvement addresses the anxiety.

Consider Medicare's specific requirements.

Medicare has specific coverage rules by diagnosis. Review CMS guidance for Medicare clients.

Mistake #7: Modifier Misuse

What Goes Wrong

Modifiers provide additional information about services. Incorrect modifier use leads to payment reductions, denials, or compliance issues.

Common Scenarios

Missing telehealth modifier: Telehealth service billed without modifier 95 (synchronous) or 93 (audio-only).

Place of service mismatch: Telehealth modifier without corresponding place of service code.

Incorrect modifier 59: Using this "distinct service" modifier inappropriately to bypass bundling edits.

Missing modifier 25: E/M visit with same-day procedure, but modifier 25 not applied to E/M code.

Supervision modifier errors: Billing under supervising provider with incorrect incident-to modifiers.

How to Prevent It

Understand required modifiers.

Match modifiers to place of service.

Build modifier logic into your system.

Your billing software should prompt for or auto-apply appropriate modifiers based on service type and location.

Mistake #8: Duplicate Billing

What Goes Wrong

Billing for the same service twice—or billing services that shouldn't be reported together—triggers denials and audit flags.

Common Scenarios

Same service billed twice: System error or manual entry causes duplicate claim.

Unbundling: Billing separately for services included in another code.

Inappropriate code combinations: Billing codes together that CCI (Correct Coding Initiative) edits prohibit.

Billing multiple units incorrectly: Misunderstanding how units work for a given code.

How to Prevent It

Use billing software with duplicate detection.

Your system should flag potential duplicates before claims are submitted.

Understand bundling rules.

Some services are included in others. Example: 90785 (interactive complexity) can't be billed without a base psychotherapy code.

Review CCI edits.

The CMS CCI edits define which code pairs can't be billed together. Your billing software should incorporate these.

Audit for patterns.

Regularly review claims for duplicate billing patterns.

Mistake #9: Not Following Up on Denials

What Goes Wrong

Denied claims represent significant revenue—often recoverable with appropriate follow-up. Yet many practices let denials fall through the cracks.

The denial reality:50%+ of denials are recoverableMany practices never resubmit denied claimsAverage time to resolve a denial: 6+ hours of staff time if manual

Common Scenarios

Denial sits in queue: Denial received but nobody acts on it.

Timely filing exceeded: By the time denial is addressed, it's too late.

Wrong approach to appeal: Practice doesn't know how to effectively appeal.

Same errors repeated: Denial pattern continues because root cause not addressed.

How to Prevent It

Track denials systematically.

Every denial should be logged with:Denial reason codeRequired actionResponsible partyDeadline for actionResolution status

For comprehensive denial management, see our claim denials guide.

Categorize and prioritize.

Some denials are quick fixes (patient info correction); others require appeals. Prioritize by dollar value and recovery likelihood.

Analyze denial patterns.

If the same denial reason appears repeatedly, address the root cause rather than fixing claims one at a time.

Set denial follow-up benchmarks.

Track: Denial rate (target: 90%), write-off rate. If these are off, investigate.

Should I outsource billing to avoid mistakes?

Billing companies can provide expertise and efficiency, but you're still responsible for compliance. If outsourcing, vet carefully, monitor performance, and maintain oversight.

What should I do if I discover a pattern of billing errors?

Document what you found. Quantify the scope. Consult with a healthcare attorney if significant. Consider voluntary refund/disclosure. Implement corrective action. Document everything.

How often should I audit my billing?

Monthly spot-checks of a sample of claims. Quarterly comprehensive review of denial patterns, coding distribution, and compliance indicators. Annual deep-dive or external audit.

Want to reduce billing errors and improve revenue capture? Ease Health's platform includes built-in eligibility verification, coding assistance, denial tracking, and compliance tools. Schedule a demo to see how we can help streamline your billing operations.

Related Glossary TermsCPT Codes — Correct coding to avoid the most common billing errorsClaim Denial — Understanding denial types and prevention strategiesRevenue Cycle Management — The full billing process and where errors occurInsurance Credentialing — Credentialing gaps that cause claim rejectionsERA — How to spot billing mistakes in remittance data

Next steps

• Review the key takeaways and adapt them to your practice workflow.
• Use the details section as a checklist when you implement or troubleshoot.
• Share this with your billing or admin team to align on process and terminology.