US Medical Code Database

What This Database Contains

This database assembles two of the primary code sets used in US healthcare billing, clinical documentation, and insurance reimbursement: the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM), and the Healthcare Common Procedure Coding System Level II (HCPCS Level II). Together they cover the diagnostic and procedural language that clinicians, hospitals, payers, and researchers use every day.

The ICD-10-CM data reflects the FY2027 release published by the CDC National Center for Health Statistics (NCHS). The HCPCS Level II data reflects the October 2026 quarterly release published by the Centers for Medicare and Medicaid Services (CMS). Both code sets are drawn directly from official government sources and are presented here for reference and educational purposes.

Understanding ICD-10-CM Codes

ICD-10-CM stands for International Classification of Diseases, Tenth Revision, Clinical Modification. It is the US implementation of the WHO's ICD-10 framework, adapted by NCHS to capture the clinical detail required for US healthcare settings. Every diagnosis documented in a US clinical encounter — from a routine annual physical to a complex inpatient stay — is assigned at least one ICD-10-CM code. Insurers use these codes to adjudicate claims; public health agencies use them to track disease burden; researchers use them to study outcomes; hospitals use them for case-mix and quality reporting.

The ICD-10-CM code structure follows a consistent logic. Every code begins with a letter (the chapter prefix), followed by two digits that identify the category, a decimal point, and then one to four additional characters that capture increasing levels of specificity — the anatomic site, the laterality (right vs. left), the encounter type (initial, subsequent, or sequela), and other clinical modifiers. A code like A00.1, for example, means cholera due to Vibrio cholerae 01, biovar eltor — where "A" denotes Chapter 1 (Certain Infectious and Parasitic Diseases), "00" identifies the category (Cholera), and ".1" specifies the biovar.

Codes are classified as either "billable" or "non-billable header codes." A billable code has sufficient specificity for claim submission; a header code represents a broader grouping and must be further specified. Out of the 98,403 codes in this release, 74,879 are billable. The database contains 1,921 category-level entries spread across 289 code blocks in 22 chapters.

Who Uses ICD-10-CM Codes

Physicians and advanced practice providers assign ICD-10-CM codes at every patient encounter to document why care was delivered. Medical coders working in hospital billing departments translate clinical documentation into codes for claim submission. Health information management (HIM) professionals maintain coding accuracy and compliance. Insurance companies and managed care organizations use codes to determine coverage, authorize services, and calculate reimbursement. Public health agencies at the local, state, and federal level track disease incidence, prevalence, and outcomes through ICD data. Epidemiologists and clinical researchers use coded datasets to study disease patterns, drug safety, and treatment effectiveness. Quality reporting programs operated by CMS, such as the Merit-based Incentive Payment System (MIPS), incorporate ICD codes into performance measures.

For foreign residents navigating the US healthcare system, understanding ICD codes can help clarify what appeared on an Explanation of Benefits (EOB), interpret a medical record, or communicate with a healthcare provider about a documented diagnosis. This database provides a plain-language reference — descriptions, clinical notes, includes and excludes annotations — to support that understanding.

Understanding HCPCS Level II

HCPCS stands for Healthcare Common Procedure Coding System. It has two levels: Level I consists of the American Medical Association's CPT (Current Procedural Terminology) codes, which are proprietary. Level II, maintained by CMS, covers products, supplies, and services not described by CPT codes — including durable medical equipment (DME), orthotics, prosthetics, ambulance services, drugs administered by injection, and many other items. HCPCS Level II codes are alphanumeric: a single letter followed by four digits (for example, A0021 for an ambulance service, or J0120 for an injection of tetracycline). CMS updates HCPCS Level II quarterly, making it one of the more frequently revised code sets in US healthcare.

This database contains 7,460 HCPCS Level II codes from the October 2026 quarterly release, organized into 16 sections by letter. Each entry includes the full code description, a short description for compact display, and the pricing indicator used by CMS to determine how the code is priced under Medicare.

How to Use This Database

Use the filter bar above to search by keyword or section name. To browse by diagnosis topic, use the ICD-10-CM chapter grid below — each chapter groups related conditions (for example, Chapter 2 covers Neoplasms, Chapter 9 covers Diseases of the Circulatory System). To look up a specific procedure supply or service, browse the HCPCS section grid by letter. Individual code pages include all annotated notes from the official tabular list, including includes, excludes type 1, excludes type 2, use additional code, code first, and code also instructions.

This reference is published for informational purposes only. It does not constitute medical, legal, or billing advice. For claim coding and compliance questions, consult a certified professional coder (CPC) or certified coding specialist (CCS). All code descriptions are reproduced from publicly available government publications.