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PR-229 Code: Medicare Type of Bill 12X Partial Charge

PR-229 reports a partial charge amount Medicare did not consider because the initial claim was a Type of Bill 12X (hospital inpatient Part B). It is used only in the 837, for coordination of benefits, when a secondary payer's cost-avoidance policy lets providers bypass a prior payer.

Quick facts

Code
PR-229 (CARC 229)
Status
Active In use since January 25, 2009; last modified July 1, 2017.
Code set
Claim Adjustment Reason Codes (CARC)
Group codes
  • PR (Patient Responsibility): X12 restricts CARC 229 to the PR group. It shows the amount as patient responsibility after Medicare in the COB data sent to the secondary payer.
Official description
Partial charge amount not considered by Medicare due to the initial claim Type of Bill being 12X. Usage: This code can only be used in the 837 transaction to convey Coordination of Benefits information when the secondary payer's cost avoidance policy allows providers to bypass claim submission to a prior payer. (Use only with Group Code PR)
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What PR-229 means

CARC 229 reads: partial charge amount not considered by Medicare due to the initial claim Type of Bill being 12X. Its usage note narrows it a lot: it can only be used in the 837 transaction to convey coordination of benefits information when the secondary payer’s cost avoidance policy allows providers to bypass claim submission to a prior payer, and only with group code PR.

Type of Bill 12X is a hospital inpatient Part B claim. Hospitals use it when a patient is an inpatient but Part A will not pay for the stay, so certain ancillary services are billed under Part B instead. Part B does not consider every charge on that bill. CARC 229 lets the hospital tell a secondary payer, usually a Medicaid program, which part of the charge Medicare would not have considered, without first sending that portion to Medicare.

This is an institutional, hospital-billing code. Physician practices and most outpatient billers will not use it.

When it applies

  • Hospital inpatient Part B billing under Type of Bill 12X.
  • Secondary payers with cost-avoidance policies, such as some state Medicaid programs, that allow skipping the Medicare submission for charges Medicare will not consider.
  • Building the COB loop of the 837 (loops 2320/2430) for that secondary claim.

How to use it correctly

  1. Confirm the secondary payer’s policy allows bypassing Medicare for the charges involved. Check its companion guide.
  2. Identify the non-considered portion of the 12X claim based on Medicare Part B inpatient billing rules.
  3. Report it with PR-229 in the 837 COB adjustment segment, with group code PR only.
  4. Keep supporting records that show why Medicare would not consider the amount.
  5. If the secondary payer rejects the claim, read its response; it may not accept the bypass for that service or date.

How to prevent problems

  • Keep an up-to-date list of which secondary payers allow cost avoidance and under what conditions.
  • Build claim edits that allow CARC 229 only on claims tied to a 12X initial claim and only with group PR.
  • Train hospital billing staff on the difference between reporting CARC 229 and reporting actual Medicare payments with CARC 23. See eligibility and COB denials for broader coordination of benefits guidance.

Remark codes that may appear with PR-229

  • MA30 (Missing/incomplete/invalid type of bill.): Relates to a missing or invalid type of bill, which is central to how this adjustment is determined.
  • N36 (Claim must meet primary payer's processing requirements before we can consider payment.): The secondary payer may still require the primary's processing requirements to be met.
  • OA-23 (The impact of prior payer(s) adjudication including payments and/or adjustments. (Use only with Group Code OA)): The general code for reporting a prior payer's impact on a secondary claim.
  • OA-22 (This care may be covered by another payer per coordination of benefits.): Care may be covered by another payer per coordination of benefits.
  • CO-109 (Claim/service not covered by this payer/contractor.): The claim was sent to the wrong payer or contractor.

PR-229 FAQ

What is Type of Bill 12X?

It is the institutional type of bill for hospital inpatient services billed under Medicare Part B, often when Part A does not pay for the stay. The X is the claim frequency digit.

Will I see PR-229 on an 835?

It is defined for use in the 837 to convey coordination of benefits information, not as a remittance adjustment from Medicare. Hospitals mainly encounter it when building secondary claims.

When can a provider bypass the prior payer?

Only when the secondary payer's cost-avoidance policy allows it. Check the secondary payer's companion guide or provider manual before skipping primary submission.

Can a professional practice use CARC 229?

No. It is tied to the institutional Type of Bill 12X, which only hospitals submit. Professional claims report Medicare adjustments with other codes, such as CARC 23 in coordination of benefits data.