OA-23: Prior payer’s adjudication

What causes it

• Normal secondary processing — the secondary is accounting for the primary’s payment and adjustments
• The primary’s explanation of benefits was transmitted incorrectly, so the secondary calculated from the wrong numbers
• Primary and secondary were applied in the wrong order
• The primary’s contractual adjustment was reported as a payment or vice versa

How to work it

1. Confirm this is genuinely a secondary claim and that the payer order is correct before doing anything else
2. Compare the primary EOB line by line against what was transmitted to the secondary — the loop 2320 and 2430 amounts are where this usually goes wrong
3. Where the amounts match and the balance is zero, this is not a denial and needs no work; posting it as one wastes an AR caller’s day
4. Where they do not match, correct the COB information and resubmit rather than appealing

How to stop it recurring

Most OA-23 lines are correct and need nothing. The discipline worth having is telling those apart from the ones that are wrong, which means posting remittances line by line rather than in bulk.

Codes worked the same way

OA-23 is checked against the contract before any work is done. So are these, which is why a queue sorted by recovery route moves faster than one sorted by code number — the same person, in the same system, with the same evidence to hand, clears all of them in one pass.

• CO-45 — Charge exceeds the fee schedule
• CO-97 — Payment included in another service
• CO-18 — Exact duplicate claim or service
• CO-288 — Referral absent
• PR-204 — Not covered by this plan
• CO-286 — Appeal filed too late

Specialties that name this among their costliest

These are specialties whose own worst denials include one of this kind. The line under each is the denial they name, quoted from their page so you can see what the link is based on.

• Anesthesia
  Post-op pain blocks bundled into the anesthesia claim
• Ophthalmology
  Retinal imaging and fundus photography done at the same visit, with one line denied as bundled because the record never gives a separate reason for each test.
• Otolaryngology
  The operative note does not state which sinuses were entered on which side, so the sinus surgery lines are bundled together or only one side is allowed.
• Urgent Care
  A global urgent care case rate billed alongside a separate evaluation and management line where the contract pays one or the other, and the second line drops off
• Primary Care
  A preventive visit and a same-day problem visit written up in one undivided note, so the problem visit bundles into the wellness visit and is not paid separately.
• Oncology
  Payer required the drug through its contracted specialty pharmacy, the practice infused from its own stock, and the buy-and-bill claim was denied in full.

What leaving it costs

Working a denied claim costs $57.23 per denied claim in administrative time. Source. At 100 denials a month — an illustration, not a measurement of your practice — that is $5,723 a month, or $68,676 a year, in labour alone.

The figure that makes it worth spending: about 90% of initially denied claims are eventually paid. Source. The reason a denial sits is almost never that nobody knows how to work it — it is that nobody has the hours.

Questions

Code descriptions are the standard X12 claim adjustment reason and remittance advice remark code text. Payer policies differ, and the payer’s own coverage policy governs any individual claim. This page is working guidance, not legal or clinical advice.