Knowledge Base · 31 public references
RCM Reference Library
The same curated public corpus the assistant retrieves from — now browsable and searchable. Every article carries its real public source (X12 · WPC · CMS). Read it here, or ask the assistant a grounded question about any of it.
31 articles across 6 categories
Codes
CARC / RARC claim adjustment + remark codes · 10 articlesCARC 16 — Missing Information / Submission Error (and how to appeal)
CodesOfficial meaning: CARC 16 reads "Claim/service lacks information or has submission/billing error(s) which is needed for adjudication." It is one of the most common denial reason…
CARC 18 — Duplicate Claim/Service
CodesOfficial meaning: CARC 18 reads "Exact duplicate claim/service." The payer has determined the claim or service line duplicates one already received (and possibly already paid or…
CARC 197 — Precertification / authorization absent (prior auth denial)
CodesOfficial meaning: CARC 197 reads "Precertification/authorization/notification/pre-treatment absent." It is the canonical prior-authorization denial.
CARC 45 (CO-45) — Charge exceeds fee schedule / contracted amount
CodesOfficial meaning: CARC 45 reads "Charge exceeds fee schedule/maximum allowable or contracted/legislated fee arrangement." It almost always appears with the CO (Contractual…
CARC 50, 109, 29 — Medical necessity, wrong payer, timely filing
CodesCARC 50 — "These are non-covered services because this is not deemed a 'medical necessity' by the payer." The payer determined the service was not medically necessary for the…
CARC 97 — Benefit included in another service (bundling)
CodesOfficial meaning: CARC 97 reads "The benefit for this service is included in the payment/allowance for another service/procedure that has already been adjudicated." It is the…
CARC and RARC: What Claim Adjustment Codes Are
CodesWhen a payer adjudicates a healthcare claim, it rarely pays the full billed amount without explanation. Two standardized public code sets explain every adjustment on the…
How CARC and RARC Code Sets Are Maintained
CodesCARC and RARC are national standard code sets named under HIPAA for use on the X12 835 remittance advice. Because they are standards, no single payer can invent its own reason…
PR-1, PR-2, PR-3 — Deductible, Coinsurance, Copay (patient responsibility)
CodesThese three codes carry the PR (Patient Responsibility) group code, meaning the amount can and should be billed to the patient. They are not denials — they are normal cost-sharing…
RARC — Remittance Advice Remark Codes (N and M codes)
CodesRemittance Advice Remark Codes (RARC) are a HIPAA-standard public code set, maintained by X12 and published by the Washington Publishing Company (WPC), used to convey *additional…
Denials
Denial categories and prevention · 3 articlesDenial Categories: Hard vs Soft, Clinical vs Administrative
DenialsA claim denial is a payer's refusal to pay all or part of a submitted claim. Denials are categorized several ways in revenue cycle management, and the category determines the…
Denial Prevention Strategy: Prevent, Don't Just Rework
DenialsReworking denials is expensive and slow. A mature revenue cycle shifts effort *upstream* — preventing denials rather than chasing them after the fact.
Timely Filing Limits and How to Protect Them
DenialsWhat it is. Every payer sets a timely-filing limit — the maximum time after the date of service within which a claim must be received to be eligible for payment. Miss it and the…
Appeals
Appeal levels, letters, and timely filing · 3 articlesCommercial Payer Appeal Levels and Timely-Filing Windows
AppealsWhen a claim is denied, providers (and patients) have the right to appeal. Commercial / ERISA plans generally follow a tiered process, distinct from Medicare's process.
Medicare Fee-for-Service Appeals: The Five Levels
AppealsMedicare has a formal, statutory five-level appeals process for Part A and Part B claim denials. The terminology differs from commercial appeals — note especially…
Writing an Effective Denial Appeal Letter
AppealsA denial appeal succeeds when it directly rebuts the specific reason the payer gave. A generic "please reconsider" letter usually fails. Effective appeals share a structure:
Prior Auth
Precertification and authorization friction · 2 articlesPrior Authorization Friction and Automation Opportunities in RCM
Prior AuthPrior authorization is widely cited as one of the most burdensome, costly, and least-automated transactions in healthcare administration. Understanding the friction points…
Prior Authorization: What It Is and Why It Exists
Prior AuthDefinition. Prior authorization (also called precertification, preauthorization, or prior approval) is a requirement that a provider obtain approval from the health plan *before*…
Claim Lifecycle
Eligibility → coding → claim → posting → collections · 9 articlesCore RCM KPIs: Clean-Claim Rate, Days in A/R, Denial Rate, Net Collection Rate
Claim LifecycleThese metrics quantify the health of a revenue cycle and are the levers an AI/automation strategy is measured against.
Eligibility Verification and Coordination of Benefits (COB)
Claim LifecycleEligibility verification confirms, before service, that a patient has active coverage and what their benefits are — plan, effective dates, covered services, copay, coinsurance,…
Medical Coding Standards: ICD-10, CPT, HCPCS, and Modifiers
Claim LifecycleCoding translates clinical documentation into the standardized codes that drive claims and payment. Errors here cause a large share of denials.
Patient Responsibility and Patient Collections
Claim LifecycleAfter insurance adjudicates, the patient's share — the patient responsibility amount — must be billed and collected. On the remittance this is reported with PR group-code CARCs:…
RCM Glossary: Key Acronyms and Terms
Claim LifecycleRevenue Cycle Management Glossary RCM — Revenue Cycle Management. The financial process tracking patient service revenue from first contact to final payment. A/R — Accounts…
Revenue Cycle Management: End-to-End Overview
Claim LifecycleDefinition. Revenue Cycle Management is the financial process healthcare organizations use to track patient service revenue from the first patient contact through final payment of…
The Claim Lifecycle: From Charge to Cash
Claim LifecycleA single claim travels through a defined sequence. Each handoff is a place where revenue can leak.
The Clearinghouse: Claim Scrubbing and EDI Routing
Claim LifecycleA clearinghouse is an intermediary that sits between providers and payers in the electronic claim lifecycle. It receives claims from providers, validates and reformats them, and…
Underpayment Detection and Contractual Analytics
Claim LifecycleNot every revenue leak is a denial. A claim can be *paid* — just paid less than the contract requires. Detecting underpayments is a distinct, high-value RCM discipline.
Remittance
EOB / ERA / 835 and payment posting · 4 articlesEligibility and Status Transactions: 270/271 and 276/277
RemittanceBeyond the claim (837) and remittance (835), several other HIPAA-standard X12 transactions support the revenue cycle. Knowing the pair numbers is part of RCM fluency.
EOB vs ERA: What's the Difference?
RemittanceThese two documents are constantly confused. They convey overlapping information but serve different audiences and formats.
The 835 Transaction — Electronic Remittance / Payment Advice
RemittanceThe 835 is the HIPAA-mandated X12 EDI transaction set used by payers to send the electronic remittance advice (ERA) and payment details to providers. It is the structured…
The 837 Transaction — Electronic Health Care Claim
RemittanceThe 837 is the HIPAA-mandated X12 EDI transaction set used to submit a healthcare claim electronically from a provider (often via a clearinghouse) to a payer. It is the electronic…