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Medical Billing & RCM Glossary

Plain-English definitions for 50 of the most common terms in medical billing, coding, compliance, and revenue cycle management. Bookmark this page.

A B C D E G H I L M N O P R T U #

A

ABN

Advance Beneficiary Notice, Medicare notice given before a service CMS may deny as not covered.

ANSI X12

EDI standard family defining HIPAA transaction formats like 837, 835, 270.

APC

Ambulatory Payment Classification, Medicare OPPS outpatient payment grouping.

B

BAA

Business Associate Agreement, HIPAA contract between covered entities and PHI-handling vendors.

C

CAQH

Council for Affordable Quality Healthcare, centralized credentialing data via CAQH ProView.

CARC

Claim Adjustment Reason Code, standardized code explaining why a claim was adjusted or denied.

Clearinghouse

Intermediary that translates, scrubs, and routes EDI transactions between providers and payers.

CMS-1450

CMS designation for the UB-04 institutional claim form used by facilities.

CMS-1500

Standard paper claim form used for professional (physician) services.

COB

Coordination of Benefits, determines payer order when a patient has multiple coverages.

CPT

Current Procedural Terminology, 5-digit AMA code set for reporting medical services.

D

DRG

Diagnosis-Related Group, inpatient prospective payment classification.

E

EDI

Electronic Data Interchange, structured electronic exchange of claims and other transactions.

EFT

Electronic Funds Transfer, direct-deposit payment mechanism used by payers to settle claims.

EOB

Explanation of Benefits, document sent to patient explaining claim adjudication.

EOP

Explanation of Payment, provider-facing remittance summary, often paired with ERA.

ERA

Electronic Remittance Advice, HIPAA 835 transaction with claim payment detail.

G

GPCI

Geographic Practice Cost Index, regional adjustment applied to RVUs.

H

HCPCS

Healthcare Common Procedure Coding System, CMS code set for supplies, DME, drugs.

HIPAA

Federal privacy and security standards for health data.

HIPPS

HIPPS codes, classification used in home health and SNF prospective payment.

HITRUST

Certifiable security framework commonly required in healthcare vendor contracts.

I

ICD-10

International Classification of Diseases, 10th Revision, diagnosis (CM) and inpatient procedure (PCS) code sets.

IPPS

Inpatient Prospective Payment System, Medicare DRG-based hospital inpatient payments.

L

LCD

Local Coverage Determination, MAC-issued policy on Medicare coverage for a specific service.

M

MAC

Medicare Administrative Contractor, private contractor that processes Medicare Part A/B claims.

MDS

Minimum Data Set, standardized SNF resident assessment driving PDPM payment.

MPFS

Medicare Physician Fee Schedule, annual CMS Part B physician services schedule.

MS-DRG

Medicare Severity DRG, reflects patient severity and comorbidities.

MSP

Medicare Secondary Payer, rules determining when Medicare pays secondary to other coverage.

N

NCCI

National Correct Coding Initiative, CMS edits preventing improper code-pair billing.

NCD

National Coverage Determination, CMS-issued national Medicare coverage policy.

NOA

Notice of Admission, home health notification required for PDGM 30-day billing periods.

NPI

National Provider Identifier, 10-digit unique identifier for US healthcare providers.

O

OASIS

Outcome and Assessment Information Set, CMS-required home health assessment.

OPPS

Outpatient Prospective Payment System, Medicare payment system for hospital outpatient.

P

PDGM

Patient-Driven Groupings Model, Medicare home health payment model (2020+).

PDPM

Patient-Driven Payment Model, Medicare SNF payment model replacing RUG-IV.

PHI

Protected Health Information, individually identifiable health information under HIPAA.

POS

Place of Service, 2-digit claim field identifying where service was delivered.

R

RA

Remittance Advice, general term for payer payment detail document (ERA or paper).

RARC

Remittance Advice Remark Code, supplementary detail on a CARC adjustment.

RVU

Relative Value Unit, Medicare physician fee schedule component.

T

TIN

Tax Identification Number, IRS-issued identifier used on claims for payment routing.

TPL

Third Party Liability, non-Medicaid payer responsible for payment ahead of Medicaid.

U

UB-04

Uniform Bill 2004, institutional claim form used by hospitals, SNFs, and home health.

#

270 / 271

HIPAA eligibility inquiry (270) and response (271) transactions.

276 / 277

HIPAA claim status inquiry (276) and response (277) transactions.

278

HIPAA prior authorization request and response transaction.

835

HIPAA EDI transaction carrying ERA claim payment and adjudication detail.

837

HIPAA EDI transaction for electronic claim submission (837P professional, 837I institutional).

Detail pages for each term are being published on a rolling basis. In the meantime, each card shows the core definition above. TODO: individual term pages.