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Medical Billing Fundamentals

Mastering the fundamentals is the first step toward a real career in US medical billing — and it’s the part most beginners rush through, which is exactly why so many people get stuck later when a denial mentions a term they’ve never seen.

This section covers everything from how the US healthcare system is structured, to how a claim actually moves from patient visit to final payment, to the regulatory bodies (CMS, AMA, AAPC) that set the rules everyone in this industry works within.

I’ve organized this into three modules, in the order I’d recommend learning them if you’re starting from zero. If you already work in billing or AR calling, feel free to jump to whichever module fills a gap in your knowledge.

 

 

Module 1

The big picture. Before any code or claim makes sense, you need to understand how US healthcare actually works — the players involved (providers, payers, patients), the rules they operate under, and who sets those rules. Start here if you’re completely new to the industry.

Introduction to US Healthcare

Medical Billing Overview

Revenue Cycle Management (RCM)

HIPAA Basics

CMS Overview

AMA Overview

AAPC Overview

Insurance Basics

 

Module 2


Before the claim is even coded. Every claim’s outcome is partly decided before a single CPT code is entered — at registration, eligibility verification, and prior authorization. Most denials I work as an AR Caller trace back to a mistake made at one of these early steps.

Patient Registration

Insurance Verification

Prior Authorization

Referrals

Medical Necessity

 

Module 3


The coding and claim-detail layer. This module covers the codes and claim fields that determine whether a claim gets paid cleanly or denied — ICD-10, CPT, HCPCS, modifiers, place of service, and revenue codes. Get comfortable here before moving into denial management.

Revenue Codes

ICD-10-CM

CPT

HCPCS

Modifiers

Place of Service (POS)

Type of Bill (TOB)