Question

8. Describe how to use the most current diagnostic coding classification system. (IX.C.2)

Answer 1

Two common medical coding classification systems are in use — the International Classification of Diseases (ICD) and the Current Procedural Terminology (CPT). ICD is the standard international system of classifying mortality and morbidity statistics, and it’s used by more than 100 countries. The system is used by health care facilities to define diseases and allocate resources to provide care. According to the World Health Organization (WHO), 70% of the world’s health care expenditures are allocated using ICD. The current version, ICD-10, features more than 68,000 codes for infections and parasitic diseases, neoplasms, and congenital malformations, as well as diseases of the digestive system, respiratory system, and nervous system.

ICD codes are alphanumeric designations given to every diagnosis, description of symptoms and cause of death attributed to human beings. These classifications are developed, monitored, and copyrighted by the World Health Organization (WHO). In the U.S., the NCHS (National Center for Health Statistics), part of CMS (Centers for Medicare & Medicaid Services) oversees all changes and modifications to the ICD codes, in cooperation with WHO.

The ICD-10-CM (International Classification of Diseases, 10th Revision, Clinical Modification) coding system, connects health issues that arise in patients, by using three- to seven-digit alphanumeric codes to indicate signs, symptoms, diseases, conditions, and injuries to payers injuries, diseases, and conditions. These codes are used in conjunction with CPT (procedural) codes to record services rendered by a provider to a patient and is documented in the medical record and then reported to a payer for reimbursement.

Coding, at its simplest, is the assignment of a number to a verbal statement or description. The International Classification of Diseases is a system for transforming verbal descriptions of diseases, injuries, conditions, and inpatient procedures into numeric codes. In compliance with the Health Insurance Portability and Accountability Act of 1996 (HIPAA), the Centers for Medicare and Medicaid Services (CMS) mandated that all health care providers use the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD9-CM) code set to report inpatient and outpatient diseases, injuries, conditions, etc. The ICD-9-CM is updated and revised annually and is being replaced with the tenth revision (ICD-10-CM). Health care providersmust begin using ICD-10-CM to code the reasons for patient encounters and ICD-10-PCS for coding hospital and inpatient procedures in the near future, and the current implementation date set by the CMS may be found on their Web site at www.cms.gov/ICD10. It is essential that the physician and medical assistant work together to achieve accurate documentation, code assignment, and reporting of diagnoses and procedures. Use of standardized codes makes it easier for third-party payers to understand the reason for the patient’s encounter with the health care provider and increases the likelihood of timely processing of claims and prompt payment when appropriate. Coding is a way to standardize medical information for purposes such as collecting health care statistics, performing a medical care review, and indexing medical records. It is also used for health insurance claims processing (see Chapter 13). Because coding is the basis for reimbursement, it is imperative that you code patient visits accurately and precisely. Incorrect, insufficient, or incomplete coding on claims forms can lead to nonpayment for the physician as well as incorrect information in the insurance companies’ databases, which may affect the patients’ insurability. For example, if a patient complaining of chest pain is coded as having “acute myocardial infarction” instead of “chest pain,” that patient may be incorrectly labeled as having heart disease. The Current Procedural Terminology (CPT) codes, which are used to report services and procedures performed by health care providers, determine the amount paid (see Chapter 12), but the code assigned to the diagnosis or reason for the service or procedure provides the medical necessity for the services or procedures so that claims are paid. The third-party payer needs to know why the service was performed to assess medical necessity. Medical necessity means the procedure or service would have been performed by any reasonable physician under the same or similar circumstances. The ICD-9 and ICD10 diagnosis codes convey this information. Is a chest radiograph medically necessary for a patient who has gout? No, but it may be necessary for a patient with acute bronchitis. The diagnosis justifies or supports the procedure. Since Medicare considers certain procedures medically necessary only at certain intervals, having the patient sign an advance beneficiary notice (ABN) will ensure payment of treatments and procedures that will likely be denied by Medicare. An example is a Pap smear for a low-risk woman, which will be paid for once every 2 years. If the physician considers it not to be medically necessary, but the patient wants a Pap test, the patient will be responsible for payment and must sign an ABN. DIAGNOSTIC CODING The ICD-9-CM is a statistical classification system based on the ICD-9, developed by the World Health Organization (WHO). The CM, which stands for clinical modification, addresses the intent of these codes to describe the clinical picture of the patient. These codes are much more precise than those needed for statistical grouping and trend analysis found in the ICD-9 and used in hospital coding. The new ICD-10 diagnosis codes classification system provides significant improvements over ICD-9-CM with more detailed and current information. The new system will provide for expansion and increased specificity to more accurately describe diseases, injuries, and conditions. These alphanumeric codes are three to seven digits long and always begin with a letter followed by a number. The remaining digits (three through seven) can be alpha or numeric. There are approximately 70,000 diagnosis codes and 72,000 procedure codes in the ICD-10-CM. Until recently, the ICD-9-CM has been the most comprehensive statistical classification of its kind. These numeric codes have three to five digits and supplementary codes that begin with a letter followed by up to four digits. Containing more than 13,000 diagnoses codes and less than 4,000 procedure codes, it consists of three volumes: • Volume 1: Tabular List of Diseases • Volume 2: Alphabetic Index of Diseases • Volume 3: Tabular List and Alphabetic Index of Procedures (Inpatient) The ICD-9-CM and ICD-10-CM codebooks are available in different formats, such as manuals, computer software, or a Web-based format, and may be purchased from several publishers.

The following table lists the chapter number (using Roman numerals), the code range of each chapter, and the chapter's title from the international version of the ICD-10.[11]

ICD-10 chapters

Chapter	Block	Title
I	A00–B99	Certain infectious and parasitic diseases
II	C00–D48	Neoplasms
III	D50–D89	Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
IV	E00–E90	Endocrine, nutritional and metabolic diseases
V	F00–F99	Mental and behavioural disorders
VI	G00–G99	Diseases of the nervous system
VII	H00–H59	Diseases of the eye and adnexa
VIII	H60–H95	Diseases of the ear and mastoid process
IX	I00–I99	Diseases of the circulatory system
X	J00–J99	Diseases of the respiratory system
XI	K00–K93	Diseases of the digestive system
XII	L00–L99	Diseases of the skin and subcutaneous tissue
XIII	M00–M99	Diseases of the musculoskeletal system and connective tissue
XIV	N00–N99	Diseases of the genitourinary system
XV	O00–O99	Pregnancy, childbirth and the puerperium
XVI	P00–P96	Certain conditions originating in the perinatal period
XVII	Q00–Q99	Congenital malformations, deformations and chromosomal abnormalities
XVIII	R00–R99	Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
XIX	S00–T98	Injury, poisoning and certain other consequences of external causes
XX	V01–Y98	External causes of morbidity and mortality
XXI	Z00–Z99	Factors influencing health status and contact with health services
XXII	U00–U99	Codes for special purposes