--- title: When do CARC Codes Apply? description: When do CARC Codes apply? --- [Skip to content](https://knowledge.populateemr.com/when-do-carc-codes-apply#main-content) English Show submenu for translations [More support](https://knowledge.populateemr.com/kb-tickets/new?hsLang=en) [Customer portal](https://support.populateemr.com/tickets?hsLang=en) ![](https://knowledge.populateemr.com/hs-fs/hubfs/Full%20Logo%20-%20Black-1.png?width=250&height=67&name=Full%20Logo%20-%20Black-1.png) Open main navigation Close main navigation - English Show submenu for translations - [More support](https://knowledge.populateemr.com/kb-tickets/new) - [Customer portal](https://support.populateemr.com/tickets) - [Contact us](mailto:support@populate.com) [Contact us](mailto:support@populate.com) How can we help you? - There are no suggestions because the search field is empty. 1. [Populate Help Desk](https://knowledge.populateemr.com/?hsLang=en) 2. [FAQ](https://knowledge.populateemr.com/faq?hsLang=en) October 15, 2026 # When do CARC Codes Apply? ## The article explains in which cases CARC codes apply **Claim Adjustment Reason Codes (CARCs)** apply whenever an insurer pays, reduces, or denies a claim line item differently than the original billed amount on an EOB or ERA. They communicate **why** the financial change occurred. ### Primary Applications - **Contractual Adjustments (CO):** Billed amounts exceeding the agreed payer fee schedule (e.g., **CO-45** write-off). - **Patient Responsibility (PR):** Amounts assigned to the patient (e.g., **PR-1** deductible, **PR-2** coinsurance, **PR-3** copay). - **Claim Denials (CO / OA):** Non-covered, missing information, or unbundled services (e.g., **CO-96** non-covered service, **CO-16** lacking documentation). - **Payment Adjustments:** Secondary insurance coordination or prior payment offsets. ### Key Group Code Prefixes - **CO (Contractual Obligation):** Provider write-off; cannot be billed to the patient. - **PR (Patient Responsibility):** Billed to the patient balance. - **OA / PI:** Other adjustments or payer-initiated policy reductions. *(Note: CARCs are often paired with **RARCs** for extra context.)* - [FAQ](https://knowledge.populateemr.com/faq?hsLang=en) - [Support](https://knowledge.populateemr.com/support?hsLang=en) - [Billing](https://knowledge.populateemr.com/billing?hsLang=en) - [Appointments](https://knowledge.populateemr.com/appointments?hsLang=en) - [Visit Notes](https://knowledge.populateemr.com/visit-notes?hsLang=en) - [Charts](https://knowledge.populateemr.com/charts?hsLang=en) - [Encounters](https://knowledge.populateemr.com/encounters?hsLang=en) - [Intake](https://knowledge.populateemr.com/intake?hsLang=en) - [To-Dos & Stickies](https://knowledge.populateemr.com/to-dos-stickies?hsLang=en) - [Fax & Reports](https://knowledge.populateemr.com/fax-reports?hsLang=en) - [Reports](https://knowledge.populateemr.com/reports?hsLang=en) - [Settings](https://knowledge.populateemr.com/settings?hsLang=en) - [Rachel—AI Agent](https://knowledge.populateemr.com/rachel-ai-agent?hsLang=en) - [Forms](https://knowledge.populateemr.com/forms?hsLang=en) - [Populate Continuous Care (PCC)](https://knowledge.populateemr.com/populate-continuous-care-pcc?hsLang=en) [![](https://knowledge.populateemr.com/hs-fs/hubfs/Full%20Logo%20-%20Black-1.png?width=250&height=67&name=Full%20Logo%20-%20Black-1.png)](https://knowledge.populateemr.com/?hsLang=en) 6790 Embarcadero Ln #100, Carlsbad, CA 92011 [mailto:support@populate.com](mailto:support@populate.com) Copyright © 2025, Populate EMR, Inc.