Revised October 1, 1995

Introduction

These revised coding guidelines for outpatient diagnoses have been approved for use by hospitals/physicians in coding and reporting hospital-based outpatient services and physician office visits. These guidelines replace the official guidelines on the October 1, 1994 CD-ROM.

Information about the use of certain abbreviations, punctuation, symbols, and other conventions used in the ICD-9-CM Tabular List (code numbers and titles), can be found in the section at the beginning of the ICD-9-CM on "Conventions Used in the Tabular List." Information about the correct sequence to use in finding a code is described in the Introduction to the Alphabetic Index of ICD-9-CM.

The terms encounter and visit are often used interchangeably in describing outpatient service contacts and, therefore, appear together in these guidelines without distinguishing one from the other.

Coding guidelines for outpatient and physician reporting of diagnoses will vary in a number of instances from those for inpatient diagnoses, recognizing that:

The Uniform Hospital Discharge Data Set (UHDDS) definition of principal diagnosis applies only to inpatients in acute, short-term, general hospitals.

Coding guidelines for inconclusive diagnoses (probable, suspected, rule out, etc.) were developed for inpatient reporting and do not apply to outpatients.

Diagnoses often are not established at the time of the initial encounter/visit. It may take two or more visits before the diagnosis is confirmed.

The most critical rule involves beginning the search for the correct code assignment through the Alphabetic Index. Never begin searching initially in the Tabular List as this will lead to coding errors.

1. BASIC CODING GUIDELINES FOR OUTPATIENT SERVICES
1. The appropriate code or codes from 001.0 through V82.9 must be used to identify diagnoses, symptoms, conditions, problems, complaints, or other reason(s) for the encounter/visit.
2. For accurate reporting of ICD-9-CM diagnosis codes, the documentation should describe the patient's condition, using terminology which includes specific diagnoses as well as symptoms, problems, or reasons for the encounter. There are ICD-9-CM codes to describe all of these.
3. The selection of codes 001.0 through 999.9 will frequently be used to describe the reason for the encounter. These codes are from the section of ICD-9-CM for the classification of diseases and injuries (e.g. infectious and parasitic diseases; neoplasms; symptoms, signs, and ill-defined conditions, etc.).
4. Codes that describe symptoms and signs, as opposed to diagnoses, are acceptable for reporting purposes when an established diagnosis has not been diagnosed (confirmed) by the physician. Chapter 16 of ICD-9-CM, Symptoms, Signs, and Ill-defined conditions (codes 780.0 - 799.9) contain many, but not all codes for symptoms.
5. ICD-9-CM provides codes to deal with encounters for circumstances other than a disease or injury. The Supplementary Classification of factors Influencing Health Status and Contact with Health Services (V01.0- V82.9) is provided to deal with occasions when circumstances other than a disease or injury are recorded as diagnosis or problems.
6. ICD-9-CM is composed of codes with either 3, 4, or 5 digits. Codes with 3 digits are included in ICD-9-CM as the heading of a category of codes that may be further subdivided by the use of fourth and/or fifth digits whichprovide greater specificity. A three-digit code is to be used only if it is not further subdivided. Where fourth-digit subcategories and/or fifth-digit subclassifications are provided, they must be assigned. A code is invalid if it has not been coded to the full number of digits required for that code.
7. List first the ICD-9-CM code for the diagnosis, condition, problem, or other reason for encounter/visit shown in the medical record to be chiefly responsible for the services provided. List additional codes that describe any coexisting conditions.
8. Do not code diagnoses documented as "probable", "suspected," "questionable," "rule out," or working diagnosis. Rather, code the condition(s) to the highest degree of certainty for that encounter/visit, such as symptoms, signs, abnormal test results, or other reason for the visit. Please note: This is contrary to the coding practices used by hospitals and medical record departments for coding the diagnosis of hospital inpatients.
9. Chronic diseases treated on an ongoing basis may be coded and reported as many times as the patient receives treatment and care for the condition(s).
10. Code all documented conditions that coexist at the time of the encounter/visit, and require or affect patient care treatment or management. Do not code conditions that were previously treated and no longer exist. However, history codes (V10- V19) may be used as secondary codes if the historical condition or family history has an impact on current care or influences treatment.
11. For patients receiving diagnostic services only during an encounter/visit, sequence first the diagnosis, condition, problem, or other reason for encounter/visit shown in the medical record to be chiefly responsible for the outpatient services provided during the encounter/visit. Codes for other diagnoses (e.g., chronic conditions) may be sequenced as additional diagnoses.
12. For patients receiving therapeutic services only during an encounter/visit, sequence first the diagnosis, condition, problem, or other reason for encounter/visit shown in the medical record to be chiefly responsible for the outpatient services provided during the encounter/visit. Codes for other diagnoses (e.g., chronic conditions) may be sequenced as additional diagnoses. The only exception to this rule is that patients receiving chemotherapy, radiation therapy, or rehabilitation, the appropriate V code for the service is listed first, and the diagnosis or problem for which the service is being performed listed second.
13. For patient's receiving preoperative evaluations only, sequence a code from category V72.8, Other specified examinations, to describe the pre-op consultations. Assign a code for the condition to describe the reason for the surgery as an additional diagnosis. Code also any findings related to the pre-op evaluation.
14. For ambulatory surgery, code the diagnosis for which the surgery was performed. If the postoperative diagnosis is known to be different from the preoperative diagnosis at the time the diagnosis is confirmed, select the postoperative diagnosis for coding, since it is the most definitive.