Medical billing terminology: beginner glossary and examples

Medical billing terminology becomes easier when you connect each word to a task. This beginner glossary explains common US billing terms, shows how similar documents differ and gives you a fictional exercise to practice. It is intended for learners in the US, Pakistan, India and elsewhere studying the US workflow.

Start with the account, not the abbreviation

When you meet a new term, ask three questions: who creates this information, what does it tell me, and what does it not prove? For example, a claim is a request for processing; it is not proof that a payment has arrived. Keep that distinction in mind as you read.

Core medical billing terms

Claim: billing information submitted to a payer for processing. A claim can move through several responses before the account is resolved.
Charge: the amount billed for a service. It may differ from the amount recognized under the payment arrangement.
Allowed amount: the amount recognized for a covered service under the applicable plan or payment arrangement. Check the actual determination and terms.
Deductible: a cost-sharing amount that may apply before particular covered benefits begin paying. Some services can be covered before it is met.
Copay: a stated cost-sharing amount for an applicable service.
Coinsurance: a cost-sharing percentage applied under the plan rules. Do not assume the billed charge is the calculation basis.
Date of service: the date associated with the service being reported. It is different from the date a claim is sent or a payment is posted.
Accounts receivable (AR): amounts recorded as outstanding. A balance needs investigation; its presence alone does not establish who must pay it.

See the cost-sharing lesson for calculations with explicit assumptions. The examples there are not actual payer rates.

EOB, ERA and EFT: what is the difference?

An explanation of benefits (EOB) helps a member understand how a health plan processed care and what the plan reports about the charges and payment. An EOB is not itself a provider bill. A prior payment may also need to be checked against the provider account.

An electronic remittance advice (ERA) explains payment and adjustment decisions to a provider. An electronic funds transfer (EFT) concerns the transfer of money. For posting and reconciliation, match the relevant remittance information to the corresponding funds; reading an explanation alone does not prove that funds have been received.

Electronic transaction numbers you will encounter

837P: an electronic professional claim.
270/271: eligibility and benefit inquiry and response.
276/277: claim-status request and response.
277CA: claim acknowledgment.
835: claim payment/advice.

Learn the purpose before learning file details. These labels are an introduction, not an implementation guide. In particular, a 277CA acknowledgment and a 277 claim-status response serve different roles. Use the appropriate current instructions when working with actual systems.

Fictional document-matching exercise

Training account WORD-01 has four items: a software transmission entry, a payer acceptance response, an ERA showing a $76 payment and a matching $76 deposit. A colleague wants to post $76 using only the transmission entry. Which evidence is relevant?

Worked answer: The transmission entry belongs to the sending stage. It does not explain the payer decision or establish the deposit. Review the ERA for the decision and allocation, match it to the deposit, and reconcile the account before posting under the organization’s procedure. The matching amount is useful evidence, but also check the reference information so an unrelated deposit is not applied to the wrong account.

Three quick knowledge checks

Is an EOB a bill? No. Distinguish the plan explanation from a provider statement.
Does an allowed amount always equal the charge? No. Read the actual payment arrangement and response.
Does an accepted claim mean paid? No. Acceptance and payment are different events.

What to study next

Follow the beginner medical billing route, explore claims submission and payment posting, then try topic-based MCQ practice. Write one fictional account note using the terms accurately before moving on.

Roman Urdu recap

Har short form ko us ke kaam ke saath samjhein. EOB bill nahi hota; ERA payment ki explanation deta hai aur EFT paisay transfer honay se related hai. Sirf “sent” ya “accepted” dekh kar account ko paid na samjhein.

Sources and review

Original AI-assisted educational explanation; sources checked October 18, 2026. Independent human expert review remains pending. All account names and figures are fictional.