CARC B4 Active

PR-B4: Late Filing Penalty

TL;DR

PR-B4 means the patient caused the filing delay (e.g., late insurance info). Verify the patient truly caused the delay before collecting.

Action
Collect from Patient
Who Pays
Patient
Appeal
No
Patient Impact
Direct Financial
Disclaimer
This content is for informational purposes only and does not constitute professional billing advice. Always verify information against your payer contracts and current coding guidelines. Consult a certified billing specialist for specific claim issues.

What Does PR-B4 Mean?

When paired with Group Code PR, the late filing is attributed to the patient — typically because the patient delayed providing insurance information. Verify the patient caused the delay before collecting. If the provider caused the delay, absorb the cost rather than transferring it to the patient.

CARC B4 represents a late filing penalty — the claim was submitted after the payer's timely filing deadline. Every payer establishes a maximum timeframe for claim submission from the date of service: Medicare allows 12 months, while commercial payers typically require 90 to 365 days depending on the contract.

Once the filing deadline passes, the payer is not obligated to pay the claim. This makes CARC B4 one of the most financially impactful denials because the revenue is typically unrecoverable. The most successful appeals involve demonstrating the claim was actually submitted on time (with clearinghouse confirmation) or that extenuating circumstances (initial submission to wrong payer, system failures) delayed filing.

Prevention is far more effective than resolution for late filing denials. Implementing automated deadline tracking, submitting claims within 48-72 hours of service, and monitoring claim aging reports are essential operational controls.

Common Causes

Cause Frequency
Patient delayed claim information The patient failed to provide necessary insurance information in time for the provider to submit within the filing window Common
Retroactive insurance enrollment The patient's insurance was retroactively established after the filing deadline had already passed Occasional

How to Resolve

  1. Verify who caused the delay Determine whether the patient or the provider caused the late filing.
  2. Collect from patient if appropriate If the patient delayed providing insurance information, they may bear responsibility.
  3. Absorb if provider caused delay If the provider's workflow caused the late submission, do not transfer the cost to the patient.
Do Not Appeal This Code

Late filing penalties assigned to PR typically indicate the patient caused the filing delay (e.g., by not providing insurance information). Appeals are unlikely to succeed unless the provider can demonstrate the patient provided information in time.

How to Prevent PR-B4

Also Filed As

The same CARC B4 may appear with different Group Codes:

Related Denial Codes

Sources

  1. https://x12.org/codes/claim-adjustment-reason-codes
  2. https://www.mdclarity.com/denial-code/b4
  3. https://www.cms.gov/regulations-and-guidance/guidance/manuals
  4. Codes maintained by X12. Visit x12.org for official definitions.