Calwarden

Coordination of Benefits Calculator

Estimate remaining patient responsibility after primary and secondary insurance payments.

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Inputs

$
$
$

Your values stay on this device.

Results

Estimated Patient Responsibility
Total Insurance Payments$1,050.00
Estimated Covered Percent87.50%
Possible Overpayment$0.00

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Assumptions

  • All entered amounts refer to the same claim, service, or claim line.
  • Payer-specific COB rules, contractual adjustments, carve-outs, exclusions, and state rules are not inferred.
  • This is an insurance workflow estimate, not legal, coverage, billing, or benefits advice.

Sensitivity preview

Allowed Amount -10%: Estimated Patient Responsibility $30.00

Allowed Amount Current: Estimated Patient Responsibility $150.00

Allowed Amount +10%: Estimated Patient Responsibility $270.00

Formula: Estimated patient responsibility = max(0, allowed amount - primary payment - secondary payment) + non-covered amount.

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About this Coordination of Benefits Calculator

Coordination of benefits can be difficult to review when primary and secondary payers both apply payments, adjustments, or patient responsibility. This calculator turns user-entered claim assumptions into a simple remaining-balance estimate.

Who this calculator is for

  • Billing teams reviewing claims with primary and secondary coverage.
  • Benefits specialists explaining estimated remaining balances.
  • Patients or advocates checking an EOB against expected COB math.

When to use it

  • Estimate patient responsibility after two insurance payments.
  • Compare primary EOB responsibility against the balance after secondary payment.
  • Document a simple COB estimate before payer-specific review.

How to use this calculator

  1. Enter the allowed claim amount used for the estimate.
  2. Enter the primary insurance payment.
  3. Enter the secondary insurance payment or expected payment.
  4. Add any known non-covered amount that should stay patient responsibility.

Key assumptions

  • All entered amounts refer to the same claim, service, or claim line.
  • Payer-specific COB rules, contractual adjustments, carve-outs, exclusions, and state rules are not inferred.
  • This is an insurance workflow estimate, not legal, coverage, billing, or benefits advice.
  • No claim details are stored; the calculation runs from the values you enter.

Accuracy and testing

Review formula sources, default test cases, assumptions, unit handling, rounding rules, and changelog for this calculator.

View accuracy page

How this calculator works

Estimated patient responsibility = max(0, Allowed amount - Primary payment - Secondary payment) + Non-covered amount.
Estimated patient responsibility = max(0, allowed amount - primary payment - secondary payment) + non-covered amount.

Inputs explained

Allowed amount

The claim amount or contracted allowed amount used as the basis for the COB estimate.

Primary insurance payment

Amount already paid or expected from the primary payer.

Secondary insurance payment

Amount already paid or expected from the secondary payer.

Non-covered amount

Any service amount you expect to remain patient responsibility regardless of payer coordination.

Understanding your results

The result is an estimate of remaining patient responsibility after the payments entered. If the value is higher than expected, verify payer order, non-covered services, COB rules, and the EOB line items.

Example scenarios

Secondary payment reduces the balance

$1,200 allowed - $800 primary payment - $250 secondary payment leaves an estimated $150 patient responsibility before any separate non-covered amount.

Key Features

  • Instant Calculation
  • Private & Secure
  • Mobile Optimized

Tips & Best Practices

  • Use line-level EOB values when available.
  • Confirm payer order before relying on the estimate.
  • Keep non-covered services separate from amounts that may be paid by a secondary payer.

Frequently Asked Questions

Does this determine which payer is primary?
No. Enter payments based on the payer order you have already verified from the plan rules, EOB, or payer portal.
Can secondary insurance pay more than the remaining balance?
Some payer rules may create overpayment or refund scenarios. This calculator caps the remaining balance at zero and shows any calculated overpayment separately.
Are claim values stored?
No. The calculator runs locally from the assumptions you enter.