Meta Description: Dual coverage? Learn how to handle PT billing when a patient has two insurances—from COB rules to clean claim tips that get you paid faster.
How to Handle PT Billing When a Patient Has Two Insurances (Without Losing Your Mind or Your Money)
If you work in PT billing, you already know: billing physical therapy to one insurance is hard enough. Add a second one to the mix and it can feel like solving a Rubik’s cube blindfolded. From figuring out who pays first, to getting clean secondary claims out the door, to making sure you’re not leaving money on the table—it’s a lot.
At PT Billing, we specialize in the messy middle. We’ve helped dozens of practices avoid underpayments, streamline coordination of benefits (COB), and eliminate those dreaded denials caused by misfiled dual-insurance claims.
In this guide, we’ll break down exactly how to handle PT billing when your patient has two active insurance plans—and how to get paid cleanly and quickly.
Why Dual Insurance in PT Billing Is a Big Deal
Patients come in with multiple insurance plans for all kinds of reasons:
- They’re covered under their employer and their spouse’s plan
- They have Medicare plus a supplemental plan
- They were injured on the job (Workers’ Comp) but also have private insurance
- They were in an accident (Auto) and also use their health insurance
And every time this happens, it changes your billing flow. If you bill the wrong payer first or skip an EOB attachment, you’re looking at weeks or months of delays. Worse, you could end up writing off money that you were never supposed to lose.
Step One: Understand Coordination of Benefits (COB)
Coordination of Benefits (COB) is the official term for who-pays-what when a patient has more than one plan. Here’s how it works in PT billing:
Primary Insurance
Pays first. They determine their allowed amount, what they’ll reimburse, and what’s left over.
Secondary Insurance
Pays second—but only after the primary processes the claim. They may pick up coinsurance, co-pays, or denied portions (depending on coverage).
Some patients even have a third-party payer involved (Auto or WC). You’ll always want to determine the correct order of responsibility before billing anyone.
Common COB Scenarios in PT Billing
Let’s run through a few real-world examples to show how billing flows change:
1. Commercial + Commercial
Patient has their own Blue Cross plan and is also on their spouse’s UnitedHealthcare plan.
Who’s primary?
Whichever plan the patient is the subscriber on is primary. The dependent plan is secondary.
2. Medicare + Secondary (Medigap or Advantage)
If the patient has Medicare + Medigap, you:
- Bill Medicare first
- The crossover happens automatically if Medigap is on file with CMS
If the patient has a Medicare Advantage plan, you bill that plan as primary—it replaces traditional Medicare.
3. Auto or Workers’ Comp + Health Insurance
PT services due to injury or accident? You bill:
- Primary: Auto or Workers’ Comp
- Secondary: Patient’s health plan only if it allows secondary coordination for liability claims
Tip: Always get a signed letter of protection (LOP) or authorization from the payer.
Step Two: Verify Coverage and Get the COB Info
Never trust just the cards. You need to:
- Verify both policies are active
- Confirm who’s the subscriber vs. dependent
- Ask payers about COB order on file
- Document plan details, deductibles, and co-pay structure
Pro Tip: Always ask the patient to call and update COB with both insurers—some won’t process your claims at all until that’s on file.
Step Three: Submit to Primary Insurance First
This is your non-negotiable.
Even if the patient says “my secondary usually pays more,” you must bill the primary insurance first.
What to do:
- Submit claim with correct modifiers (GP, 59, KX if needed)
- Wait for EOB (Explanation of Benefits)
- Track the claim in your billing software to ensure it processes
No secondary claim should go out until that EOB is in hand.
Step Four: Bill Secondary Insurance With Proper Documentation
Once the EOB comes in, here’s how you cleanly submit to secondary:
- Enter EOB details into your system
- Include claim adjustment reason codes (CARCs)
- Attach EOB (or crossover if electronic)
- Resubmit with secondary payer info
If you’re submitting manually (or the clearinghouse doesn’t support auto-crossover), attach:
- HCFA 1500 form
- Primary EOB
- Cover sheet, if required
Don’t Forget:
- Some secondaries require COB forms to be on file
- Make sure your patient responsibility calculations are accurate
- Watch for duplicate claim denials (very common with auto-submitted secondaries)
Common PT Billing Pitfalls with Dual Insurance
- Skipping COB verification: You bill the wrong plan first, claim gets denied, and now you’re 30 days behind.
- Waiting too long to bill secondary: Some secondary plans have timely filing limits as short as 60 days.
- Not linking claims properly in your EMR: If claims aren’t attached to the same encounter, payments won’t reconcile.
- Patient confusion: Patients often think the second plan “will pay the rest.” That’s not always true.
How PT Billing Handles Dual Insurance—The Right Way
At PT Billing, our process is built for clean, efficient handling of dual insurance claims:
- Automated COB workflows: We flag all patients with multiple plans and verify their coordination status before the first visit.
- Claim pairing system: Ensures secondary claims only go out when a valid EOB is received.
- Dedicated denial management: If secondary denies or underpays, we appeal immediately with documented COB evidence.
- Patient education: We help clinics craft clear policies and scripts so front desk staff can explain insurance roles without guessing.
Pro Tips to Make Dual Insurance Billing Smoother
- Use your EMR’s COB tools. Whether you’re on WebPT, Raintree, or TheraOffice—set up COB logic rules from day one.
- Build COB training into your front desk onboarding. Everyone touching intake needs to understand how to verify and document dual coverage.
- Automate EOB imports. Let your clearinghouse do the heavy lifting to prevent missed secondary opportunities.
- Audit your dual-insurance claims monthly. Check for delays, errors, or patterns of denial.
When to Bill the Patient
You’ve billed both insurances, and now there’s a remaining balance. Can you bill the patient?
Yes—if:
- You’ve waited for both EOBs
- You’ve confirmed all contractual adjustments are applied
- The balance isn’t part of a contractual write-off
Always provide clear documentation and offer payment plans if needed. But never bill the patient before both payers have processed.
Final Thoughts: Clarity Beats Chaos in PT Billing
Dual insurance isn’t going away. In fact, with rising healthcare complexity, it’s becoming more common. But when you understand the rules, verify everything, and use a strong billing system, you don’t have to lose time or money.
You just need a system—and possibly a partner—to handle it right.