Perhaps you’re wondering what to do when you have a balance remaining after you submit a claim to your client’s primary insurance provider? Are you clear on the difference between primary and secondary insurance?
Essentially, if your client has secondary insurance, you submit a claim there for the remaining funds. So, how exactly- and correctly- is that done?
Let’s tackle the ins and outs of secondary billing together
What is Secondary Insurance Exactly?
First, it isn’t unusual for clients to have two forms of health insurance coverage.
Basically, the first provider pays the claim according to the contracted rate per the client’s insurance plan. They are referred to as “primary insurance.” The second payer, referred to as the client’s “secondary insurance,” pays the remaining balance, copay, etc.
For instance, let’s say that your client has employer insurance coverage and coverage through their partner. This means that they have primary insurance and secondary insurance.
Now, it’s important to note that neither you nor your client are in control of which plan is considered “primary”. The insurance payers make that determination. Still, in the aforementioned example, the client’s own employer-offered insurance is most likely to be primary. The spouse’s plan would be secondary.
Also, you should know that TriCare or Medicaid is usually secondary if there is another form of insurance. Medicare varies, thus, it’s wise to reach out to payers to be sure.

What Does the Secondary Billing Process Look Like?
First, understand that primary and secondary claims are not submitted at the same time.
Initially, you’ll submit your claim to the primary insurance payer and await payment. When that is paid, you can submit a claim to the secondary insurance payer. Therefore, you’ll pay primary and secondary payments in one of two ways:
Billing a Secondary Insurance Payer as Print & Mail
Some secondary insurance payers don’t accept secondary claims electronically or specify that they are “print & mail.” If this is the case, you can post the primary payment in one of three ways, according to Therabill:
- Batch Insurance ( send claims for two or more clients to their corresponding primary insurances).
- ERA (an explanation from a health plan to a provider about a claim payment).
- Single Session – Insurance w/ Adjudication (the most versatile payment entry form).
With primary claims complete, you can deal with print & mail secondary billing in the following way:
- Post the primary payment (for Therabill, this means selecting “resubmit” or “Send to Insurance Invoice Area.”)
- Navigate to your software’s billing page and select your client.
- Then, select all pertinent services and create an invoice.
- Create a Paper Claim. (On Therabill, select the
icon on the secondary insurance card).
- When your claim is correct, print the CMS-1500 form.
- Finally, attach the Explanation of Benefits (EOB) and mail your claim.
Bill a Secondary Insurance Payer Electronically
If your payer accepts electronic secondary claims, you can post the primary payment in one of three ways. Therabill describes them as follows:
- Coordination of Benefit (COB) Batch Insurance (COB is the procedure by which a health insurance company decides whether it should be the primary or secondary payer of medical claims).
- ERA (an explanation from a health plan to a provider about a claim payment).
- Single Session – Insurance w/ Adjudication Info (the most versatile payment entry form).
With primary claims complete, you can deal with electronic secondary billing in the following way:
- Post the primary payment (for Therabill, this means selecting “resubmit” or “Send to Insurance Invoice Area.”)
- Navigate to your software’s billing page and select your client.
- Select all desired services and create an invoice.
- Create an electronic claim per your software’s instructions. (For Therabill, select the
icon on the secondary insurance card).
Note: You don’t need to send a copy of the EOB to the secondary insurance if you use Therabill, as the primary adjudication information is embedded in the file.
What if You Receive a Secondary Claim Rejection?
First, you need to determine why your claim was denied. If you aren’t certain, ask! Contact the secondary insurance payer to find out, for sure, what the problem is.
With that in mind, be aware that the most common secondary claim rejection reads as follows:
“Secondary Claim Information Missing or Invalid, Line Charge Amount = Line sum of Adjustment Amts + Line Payer Paid Amt”
Is this familiar? Not to worry, with a bit of explanation you can avoid this in the future.
Secondary Claim Adjustments
To resolve this rejection, you will need to review and correct the claim adjustments listed on your secondary claim.
The secondary payer wants to see:
- the total billed amount of the claim,
- the portion the primary insurance paid on the claim,
- why the billed amount was not paid in full by the client’s primary payer.
In other words, each line must balance this way:
“Line Charge Amount = Line sum of Adjustment Amts + Line Payer Paid Amt”
This rejection indicates that the total billed amount of the secondary claim does not correctly balance with the primary payment amount and any claim adjustments.
How to avoid rejection again
Clarity is key. Adequately communicate why the total billed amount was not paid by the primary payer. Your claim must include adjustments that indicate the categories of the remaining balance.
Be sure that all that amount paid and the adjusted amounts are correctly reflected in your invoice. All of the reasons for lack of payment by the primary must be communicated. Not including adjustments to account for the entire unpaid amount will keep your claim from exiting the clearinghouse and even reaching the payer again.
Don’t be intimidated, just be precise and thorough.
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