This document provides an overview of common medical coding systems used in the United States. It discusses the International Classification of Diseases (ICD), Current Procedural Terminology (CPT) codes, and Healthcare Common Procedure Coding System (HCPCS). ICD codes are used for diagnoses. CPT codes document medical procedures and services performed by physicians. HCPCS codes include additional medical items and services not covered by ICD or CPT codes, such as durable medical equipment. The document provides details on the purpose and guidelines for each coding system.

2. Medical
Coding
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3. Medical Coding
International Classification of
Diseases
IDC
Current Procedural Terminology
CPT
Healthcare Common Procedure Coding
System
HCPCS

4. Medical
Coding
ɤ Diagnostic codes that create a uniform vocabulary for describing
the causes of injury, illness and death.
ɤ Established by the World Health Organization (WHO) in the late
1940s.
ɤ Updated several times in the 60 – plus years since its inception
ɤ The number following “ICD” represents which revision of the
code is in use.

5. Medical
Coding
ɤ Are used to document the majority of the medical procedures
performed in a physician's office.
ɤ The code set is published and maintained by the American
Medical Association (AMA).
ɤ These codes are copyrighted by the AMA and are updated
annually.

6. Medical
Coding
ɤ The Clinical Modification significantly increases the number of
codes for diagnosis.
ɤ The increased scope gives coders much more flexibility and
specificity, which is essential for the profession.
ɤ The ICD-10 code, has 14,000 codes.
ɤ Its clinical modification, ICD-10-CM, contains over 68,000.

7. Medical
Coding
ɤ CPT codes are five-digit numeric codes.
ɤ The first category is divided into six ranges which
correspond to six major medical fields:
 Evaluation and Management
 Anesthesia
 Radiology
 Surgery
 Medicine
 Pathology and Laboratory

8. Medical
Coding
ɤ The second category of CPT codes corresponds to
performance measurement and in some cases, laboratory or
radiology test results.
ɤ The five-digit, alphanumeric codes are typically added to the
end of a Category I CPT code with a hyphen.
ɤ The third category of CPT codes corresponds to emerging
medical technology.

9. Medical
Coding
ɤ CPT codes also have addendums that increase the
specificity and accuracy of the code used.
ɤ CPT Modifiers are two-digit numeric or alphanumeric codes
that are added to the end of the category I CPT code.
ɤ They provide important additional information to the
procedure code.
ɤ E.g. a CPT modifier that describes which side of the body a
procedure is performed on, and there’s also a code for a
discontinued procedure.

10. Medical
Coding
ɤ This includes durable medical equipment, prosthetics,
ambulance rides, and certain drugs and modifiers.
ɤ HCPCS is also the official code set for outpatient hospital
care, chemotherapy drugs, Medicaid, and Medicare, among
other services.
ɤ Since HCPCS codes are involved in Medicaid and Medicare,
its one of the most important code a medical coder can use.

11. Medical
Coding
ICD-10-CM
guidelines
The Centers for
Medicare &
Medicaid
Services
(CMM) website
Medical
dictionary
Novitas
Solutions
website

12. Medical
Coding
ɤ Read all four sections of the current ICD-10-CM Official
Guidelines for Coding and Reporting.
 Section I. Conventions, general coding guidelines and
chapter specific guidelines.
 Section II. Selection of Principal Diagnosis.
 Section III. Reporting Additional Diagnosis.
 Section IV. Diagnostic Coding and Reporting
Guidelines for Outpatient Services.

13. Medical
Coding
ɤ Describes structure and conventions of the classification and
general guidelines that apply to the entire classification, and
chapter-specific guidelines that correspond to the chapters as
they are arranged in the classification.
1
•Conventions for the ICD-10-CM
2
•General Coding Guidelines
3
•Chapter-Specific Coding Guidelines

14. Medical
Coding
ɤ Section II includes guidelines for the selection of principal
diagnosis for non-outpatient settings.
ɤ Section III includes guidelines for reporting additional
diagnosis in non-outpatient settings.
ɤ Section IV is for outpatient coding and reporting