The vocabulary, in plain English.
Insurance and billing depend on a small set of acronyms that everyone uses but nobody explains. Here they are, defined the way we'd want them defined for our own families.
EOB (Explanation of Benefits)
An EOB is the document your insurance plan sends after a claim is processed. It is not a bill. It lists what was billed, what the plan allowed, what the plan paid, and what's left for the patient — typically broken down by line item. Comparing it with the provider's bill can reveal discrepancies worth reviewing.
CPT code
CPT (Current Procedural Terminology) is the AMA's coding system for medical procedures and services. Depending on the claim, a reviewer may compare the billed code, modifiers, documentation, and applicable coding edits.
ICD-10 code
ICD-10 codes describe diagnoses and other clinical context, while procedure coding describes reported services. How the codes interact in claim adjudication depends on the service, documentation, payer policy, and plan.
Allowed amount
For covered services, a plan may recognize an allowed amount that helps determine the plan payment and member cost-sharing. The effect of charges above that amount depends on network status, the provider contract, plan terms, and applicable law.
Balance billing
Balance billing is a provider's attempt to collect some or all of the difference between its charge and the plan-recognized amount. Whether it is permitted depends on network contracts, plan terms, the service, care setting, notice, consent, and applicable state or federal protections.
No Surprises Act
The No Surprises Act can protect patients from certain surprise out-of-network bills involving emergency care, facility-based ancillary services, and air ambulances. Coverage depends on the plan, service, care setting, notice, and consent; official guidance and the specific records control.
Upcoding
Upcoding can arise in ER and inpatient claims, where the billed level depends on the applicable documentation and coding criteria. A review compares the record with the billed code; any correction and financial outcome depend on the full claim and insurer decision.
Unbundling
Some services may be included in another billed code under applicable coding edits. Whether two lines are improperly unbundled depends on the exact code pair, provider, modifiers, date, and documentation.
ERISA
ERISA establishes federal requirements that can govern many employer-sponsored benefit plans. The applicable internal and external review rights depend on the plan, claim, denial notice, and other federal or state rules; use the plan documents and official guidance for the exact process.
HIPAA
HIPAA's Privacy and Security Rules apply to covered entities and, in defined circumstances, their business associates. A Business Associate Agreement is required for certain covered relationships; mentioning HIPAA or using healthcare data does not by itself establish compliance.
Out-of-network
OON care typically costs more, with the patient responsible for a higher share. The provider isn't bound by the plan's allowed amount, which is what makes balance billing possible without statutory protection.
Modifier (CPT)
Modifiers such as -25 and -59 add context to how a service is reported. A reviewer checks whether the modifier and supporting documentation fit the specific services; the financial effect varies by claim and payer policy.