Module 1 · Medical Billing Fundamentals
Lesson 5 of 5

Essential Medical Billing Terminology

Medical billing uses a large vocabulary. Learning the terms early makes claims, remittances, insurance verification and denial follow-up much easier to understand.

Beginner18–22 minFree lesson

Core terminology

TermBeginner explanation
ClaimA request for payment submitted to a payer for healthcare services.
ChargeThe amount assigned by the provider or organization to a healthcare service.
Allowed amountThe amount recognized by a payer according to coverage, policy or contract terms.
CopayA fixed amount the patient may be responsible for under the benefit plan.
DeductibleAn amount a patient may need to pay before certain plan benefits begin paying according to plan rules.
CoinsuranceA percentage of an allowed cost that may be assigned to the patient under the benefit plan.
PremiumThe amount paid for insurance coverage.
EOBExplanation of Benefits — a statement explaining how a claim was processed.
ERAElectronic Remittance Advice — electronic claim-payment and adjustment information returned by a payer.
A/RAccounts Receivable — outstanding amounts that have not yet been resolved.
DenialA claim or service that the payer has processed but will not pay as submitted, requiring review of the reason and next action.
RejectionA claim that fails an edit or transmission requirement before normal payer adjudication and generally must be corrected before it can be processed.
Prior authorizationA payer process that may require approval before certain services are provided.
EligibilityChecking whether coverage is active and obtaining applicable benefit information.
NPINational Provider Identifier — a standard identifier for covered healthcare providers in the United States.
ICD-10-CMA diagnosis classification system used in the United States for reporting diseases, conditions and related health information.
CPTA code set maintained by the American Medical Association and widely used to report medical procedures and professional services.
HCPCS Level IIA standardized coding system used for certain products, supplies and services not represented by CPT.
ClearinghouseAn organization or system that can receive, validate and transmit electronic healthcare transactions between providers and payers.
Clean claimA claim containing the information needed to be processed without requiring correction or additional information.
AdjustmentA change to the billed balance based on payer processing, contract terms or another valid account action.
Patient responsibilityThe portion of an allowed or billable balance assigned to the patient after applicable claim processing and benefit rules.
Timely filingThe payer deadline for submitting an initial claim or, depending on policy, certain subsequent claim actions.
AppealA formal request asking a payer to reconsider a claim decision.
Coding note: CPT is copyrighted by the American Medical Association. This training introduces the role of CPT but does not reproduce the proprietary code set.

Rejection vs. denial

Beginners often use these words interchangeably. A rejection generally means the claim did not pass a required edit or transmission step and needs correction before normal adjudication. A denial generally follows payer processing and communicates that payment was not allowed as submitted. Actual payer workflows and terminology can vary, so staff should always review the payer response.

Quick knowledge check

What does A/R stand for?

Accounts Receivable.

Which document explains how a claim was processed: EOB or NPI?

EOB — Explanation of Benefits.

What is a clearinghouse used for?

It can receive, validate and transmit electronic healthcare transactions between providers and payers.

Does “patient responsibility” automatically mean every billed charge can be transferred to the patient?

No. Patient responsibility depends on claim processing, plan benefits, payer rules, contracts and applicable law.

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Training note: This material is for education and staff development. Payer rules, plan benefits, coding guidance, contracts and regulations change; learners should verify current requirements with authoritative payer, CMS and coding resources when performing real billing work.