> ## Documentation Index
> Fetch the complete documentation index at: https://docs.rcintell.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Glossary

> Healthcare billing and RCM terminology

## A

**ABN (Advance Beneficiary Notice)** — A notice given to Medicare patients before non-covered services.

**ALJ (Administrative Law Judge)** — The third level of Medicare appeals.

## C

**CARC (Claim Adjustment Reason Code)** — Standardized codes that explain why a claim was adjusted (denied, reduced, etc.). Used in 835 ERA responses.

**CCN (CMS Certification Number)** — A 6-digit identifier assigned to Medicare-certified facilities. Encodes the state, facility type, and sequence number.

**CF (Conversion Factor)** — The dollar amount multiplied by total adjusted RVUs to calculate Medicare payment. Updated annually by CMS.

**CMS-1500** — The standard paper claim form for professional services. Electronic equivalent: 837P.

**CPT (Current Procedural Terminology)** — A coding system maintained by the AMA for reporting medical procedures and services.

## E

**EDI (Electronic Data Interchange)** — The electronic exchange of healthcare transactions using X12 standards.

**E/M (Evaluation and Management)** — A category of CPT codes for patient visits (99201-99499).

**ERA (Electronic Remittance Advice)** — The electronic equivalent of an Explanation of Benefits. X12 transaction 835.

## G

**GPCI (Geographic Practice Cost Index)** — CMS-published indexes that adjust Medicare payment by geographic area. Three components: Work (PW), Practice Expense (PE), and Malpractice (MP).

## H

**HCPCS (Healthcare Common Procedure Coding System)** — A coding system for services, procedures, and supplies. Level I = CPT codes. Level II = alphanumeric codes for supplies and non-physician services.

**HPSA (Health Professional Shortage Area)** — Areas with a shortage of healthcare providers, which may qualify for payment bonuses.

## I

**ICD-10 (International Classification of Diseases, 10th Revision)** — The coding system for diagnoses.

**IPPS (Inpatient Prospective Payment System)** — Medicare's payment system for acute care hospital inpatient stays. Uses DRG-based payment.

## L

**LCD (Local Coverage Determination)** — A decision by a MAC about whether a service is medically necessary in their jurisdiction.

## M

**MAC (Medicare Administrative Contractor)** — Regional contractors that process Medicare claims.

**MPFS (Medicare Physician Fee Schedule)** — The system used to pay physicians for Medicare services. Payment = (Work RVU × GPCI + PE RVU × GPCI + MP RVU × GPCI) × CF.

**MUE (Medically Unlikely Edit)** — Edits that limit the number of units of service that can be billed on a single claim line.

## N

**NCD (National Coverage Determination)** — A nationwide decision by CMS about whether a service is covered by Medicare.

**NCCI (National Correct Coding Initiative)** — Edits that prevent improper coding combinations on claims.

**NPI (National Provider Identifier)** — A unique 10-digit identifier for healthcare providers.

## O

**OPPS (Outpatient Prospective Payment System)** — Medicare's payment system for hospital outpatient services. Uses APC-based payment.

## P

**POS (Place of Service)** — A two-digit code indicating where a service was performed (e.g., 11=office, 22=outpatient hospital).

## R

**RARC (Remittance Advice Remark Code)** — Supplemental codes providing additional detail about claim adjustments.

**RVU (Relative Value Unit)** — A measure of value used in the MPFS. Three components: Work RVU, Practice Expense (PE) RVU, and Malpractice (MP) RVU.

## S

**SNF (Skilled Nursing Facility)** — A facility providing 24-hour nursing care. CCN range 4000-4999.

## T

**TOB (Type of Bill)** — A 3-digit code on UB-04 claims identifying the type of facility, type of care, and billing frequency.

## U

**UB-04** — The standard paper claim form for institutional services. Electronic equivalent: 837I.

## X

**X12** — The ANSI standard for EDI transactions in healthcare. Common transactions: 270/271 (eligibility), 837P/I/D (claims), 835 (ERA), 276/277 (claim status).