Third-Party Administrator (TPA) ESIS’s apparent lack of basic knowledge about California workers’ comp billing should concern insurers like Safety National Casualty Corporation and employers like Bodega Latina.

Case in point: ESIS denied payment to a doctor by claiming that extremely common billing codes CPT 99358 and 99359 are “invalid” and not part of California’s Official Medical Fee Schedule (OMFS). That is false.

Worse, ESIS had two opportunities to correct this amateurish bill review error, and instead, doubled (and tripled) down on the denial.

Because of ESIS’s demonstrably untrue denial reasoning, daisyCollect was forced to pay $195 to request Independent Bill Review (IBR) to pursue the reimbursement this doctor is legally owed. This kind of “IBR Chicken” is a classic example of ESIS’s payment abuse, which drove at least one practice to refuse to treat injured workers where ESIS is the TPA.

When injured workers can’t find doctors willing to treat them, employers suffer the consequences: longer claim durations, delayed recoveries, and ballooning costs.

ESIS Fails Bill Review 101

The California Division of Workers’ Compensation (CA DWC) financially incentivizes bill review “errors” by ESIS and other claims administrators, encouraging the game we call IBR Chicken.

Here’s how the game works:

1. ESIS denies the provider’s bill with no apparent regard to whether the denial reasoning makes any sense (facts do not seem to matter in this game).
2. If the provider submits a Second Review appeal to dispute the denial, ESIS denies again.
3. In the best case for ESIS, the provider taps out, and ESIS keeps the reimbursement it owes to the provider (cha-ching).
4. In the worst-case scenario, the provider pays $195 to request IBR and wins. ESIS simply pays what it is already owed and faces no consequences for repeatedly refusing to pay correctly.

ESIS kicked this round off IBR Chicken by denying payment for CPT 99358 and 99359, which providers use to report prolonged non-face-to-face services on a date other than when the provider conducted Evaluation and Management services.

As the CPT 2025 Professional Edition codebook states:

“Codes 99358, 99359 may be reported for prolonged services in relation to any evaluation and management service on a date other than the face-to-face service, whether or not time was used to select the level of the face-to-face service.”

Yet, when an orthopedist sent a bill to ESIS for the care of a Bodega Latina employee, ESIS sent back the Explanation of Review (EOR) below. ESIS paid $0 for CPTs 99358 and 99359, claiming that the codes are “invalid” and that the OMFS does not include them.

ESIS Stands By Its Ineptitude

No payer is perfect. Mistakes (even obvious ones) happen. That’s why California has a Second Review process, which allows payers a chance to correct the occasional error.

…but correcting the error is not part of IBR Chicken.

daisyCollect submitted a Second Review appeal to ESIS. ESIS responded with the final EOR below, which stated, "This claim was processed properly the first time" and rehashed the fairy tale that 99358 and 99359 are not part of the OMFS.

ESIS Triples Down

With no other option, daisyCollect paid $195 and submitted a request for IBR, the process by which Maximus (a contractor for the state) determines whether or not a claims administrator paid a provider correctly.

ESIS, having twice committed the same fowl, issued the letter below to Maximus, claiming that:

“The provider’s bill was denied twice due to inappropriate billable codes. Medicare has stated that CPT codes 99358 and 99359 are no longer valid.”

While Maximus is overwhelmingly likely to decide that ESIS has to pay the bill, the odds are low that ESIS will include the required penalties, interest payments, and the $195 IBR filing fee.

CPT 99358 & 99359: Still Payable (for Workers’ Comp)

Based on its letter to Maximus, ESIS’s confusion may result from a 2023 update to Medicare, which changed the Status Code of CPT 99358 and 99359 to ‘I.’

However, as outlined in the video below, this change to Medicare billing did not render these codes non-payable under the OMFS. California Code of Regulations Section 9789.12.3 offers instructions on how payers should reimburse CPT codes with status code ‘I’ for California workers’ comp.

In other words, while the OMFS shares some rules with Medicare billing, treating a workers’ comp bill as a Medicare bill is some amateur-hour incompetence (especially when the provider’s appeal points out the error).

ESIS, workers’ comp billing is our wheelhouse. Next time we insist you were wrong to refuse payment to a doctor, do a little homework before reflexively recommitting to your mistake.

…and be advised: when claims administrators play IBR Chicken, daisyCollect clients never tap out.

daisyCollect always goes the distance for our providers. Click below to see how we can take the billing burden of your practice.

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