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OA-209 Denial Code: Not Collectible, Bill Next Payer

OA-209 means a regulatory or other agreement stops the provider from collecting this amount from the patient, but the amount may still be billed to a subsequent payer. If the patient already paid it, the provider should refund them.

Quick facts

Code
OA-209 (CARC 209)
Status
Active In use since July 9, 2007; last modified July 1, 2013.
Code set
Claim Adjustment Reason Codes (CARC)
Group codes
  • OA (Other Adjustment): Official usage limits CARC 209 to the OA group. The amount is neither a contractual write-off nor patient responsibility; it can move to the next payer, but the patient cannot be charged.
Official description
Per regulatory or other agreement. The provider cannot collect this amount from the patient. However, this amount may be billed to subsequent payer. Refund to patient if collected. (Use only with Group code OA)
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What OA-209 means

CARC 209 is an unusual adjustment with three parts in one sentence:

  1. You cannot collect this amount from the patient, because of a regulation or another agreement.
  2. You may bill it to a subsequent payer, such as a secondary or tertiary plan.
  3. If the patient already paid it, refund it.

That combination is why X12 allows CARC 209 only with the OA (Other Adjustment) group. It is not a CO contractual write-off with this payer, and it is not PR patient responsibility. It sits in between: protected from the patient, but still open for other coverage.

Example: a primary payer allows $150, pays $110, and reports $40 as OA-209. You cannot send the patient a bill for $40, but if the patient has a secondary plan, you can include the primary ERA on a secondary claim and ask the secondary payer to consider the $40.

Common causes

  • State or federal rules that protect certain patients from cost sharing, such as specific Medicaid or dual-eligible situations.
  • Program agreements where the patient is held harmless for part of the balance.
  • Payer agreements that bar balance billing but still recognize that another payer may have liability.
  • Coordination of benefits scenarios where the primary identifies an amount the secondary may pick up.

How to fix it

  1. Stop patient billing for the OA-209 amount. Remove it from statements if it has already been transferred to patient responsibility.
  2. Refund the patient if they paid any of this amount, following your refund policy and any state timelines.
  3. Check for other coverage. Review the registration record and ask the patient about secondary insurance; run an eligibility check if needed.
  4. Bill the subsequent payer with the primary payer’s adjudication details (loop 2320/2430 on the 837, or an attached EOB on paper).
  5. If there is no other payer, adjust the balance off according to your policy. It still cannot go to the patient.
  6. If you think the code is wrong (for example, no agreement applies), contact the payer for an explanation before writing anything off.

For a broader look at how primary and secondary adjustments flow, see eligibility and COB denials.

How to prevent it

  • Capture all coverage at registration and re-verify at each visit so secondary claims can go out promptly.
  • Set your practice management system so OA-209 balances move to the next payer, never to patient responsibility.
  • Train front-desk staff not to collect estimated balances from patients in protected programs.
  • Review ERAs for OA adjustments separately from denials; an ERA Analyzer can surface OA-209 balances that were never forwarded to a secondary payer.

Remark codes that may appear with OA-209

  • N381 (Alert: Consult our contractual agreement for restrictions/billing/payment information related to these charges.): Points to the contract or agreement that bars collecting the amount from the patient.
  • N130 (Consult plan benefit documents/guidelines for information about restrictions for this service.): Points to plan or program documents describing the restriction.
  • OA-23 (The impact of prior payer(s) adjudication including payments and/or adjustments. (Use only with Group Code OA)): Shows the prior payer's impact on a secondary claim, also reported under OA.
  • OA-22 (This care may be covered by another payer per coordination of benefits.): Tells you another payer may be primary, rather than that the amount goes to a subsequent payer.
  • CO-45 (Charge exceeds fee schedule/maximum allowable or contracted/legislated fee arrangement.): A contractual reduction written off by the provider; unlike 209, it is not passed to another payer.
  • CO-94 (Processed in Excess of charges.): Another OA-style adjustment, used when a payer processed more than the billed charge.

OA-209 FAQ

Can I bill the patient for OA-209?

No. The official description says the provider cannot collect this amount from the patient and must refund it if it was already collected.

Is OA-209 a write-off?

Not immediately. The amount may be billed to a secondary or other subsequent payer. Only write it off after the other payers have processed it or if no other coverage exists.

Why is OA-209 always under the OA group?

X12 restricts CARC 209 to group code OA because the amount is not the provider's contractual responsibility with this payer and not the patient's responsibility either.