ICD-10-CM Official Guidelines for Coding and Reporting
FY 2019
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i. Sequelae (Late Effects) of External Cause Guidelines ......................................................... 89
j. Terrorism Guidelines ............................................................................................................ 90
k. External cause status ............................................................................................................. 90
21. Chapter 21: Factors influencing health status and contact with health services (Z00-Z99) ... 91
a. Use of Z codes in any healthcare setting .............................................................................. 91
b. Z Codes indicate a reason for an encounter .......................................................................... 91
c. Categories of Z Codes ........................................................................................................... 91
Section II. Selection of Principal Diagnosis ........................................................................................ 107
A. Codes for symptoms, signs, and ill-defined conditions .............................................................. 107
B. Two or more interrelated conditions, each potentially meeting the definition for principal
diagnosis. .................................................................................................................................... 107
C. Two or more diagnoses that equally meet the definition for principal diagnosis ....................... 107
D. Two or more comparative or contrasting conditions .................................................................. 108
E. A symptom(s) followed by contrasting/comparative diagnoses ................................................. 108
F. Original treatment plan not carried out ....................................................................................... 108
G. Complications of surgery and other medical care....................................................................... 108
H. Uncertain Diagnosis .................................................................................................................... 108
I. Admission from Observation Unit .............................................................................................. 108
1. Admission Following Medical Observation ......................................................................... 108
2. Admission Following Post-Operative Observation .............................................................. 108
J. Admission from Outpatient Surgery ........................................................................................... 109
K. Admissions/Encounters for Rehabilitation ................................................................................. 109
Section III. Reporting Additional Diagnoses ........................................................................................ 110
A. Previous conditions ..................................................................................................................... 110
B. Abnormal findings ...................................................................................................................... 111
C. Uncertain Diagnosis .................................................................................................................... 111
Section IV. Diagnostic Coding and Reporting Guidelines for Outpatient Services ............................. 111
A. Selection of first-listed condition ................................................................................................ 112
1. Outpatient Surgery ................................................................................................................ 112
2. Observation Stay ................................................................................................................... 112
B. Codes from A00.0 through T88.9, Z00-Z99 ............................................................................... 112
C. Accurate reporting of ICD-10-CM diagnosis codes ................................................................... 112
D. Codes that describe symptoms and signs .................................................................................... 113
E. Encounters for circumstances other than a disease or injury ...................................................... 113
F. Level of Detail in Coding ........................................................................................................... 113
1. ICD-10-CM codes with 3, 4, 5, 6 or 7 characters ................................................................. 113
2. Use of full number of characters required for a code ........................................................... 113
G. ICD-10-CM code for the diagnosis, condition, problem, or other reason for encounter/visit .... 113
H. Uncertain diagnosis ..................................................................................................................... 113
I. Chronic diseases.......................................................................................................................... 114
J. Code all documented conditions that coexist.............................................................................. 114
K. Patients receiving diagnostic services only................................................................................. 114
L. Patients receiving therapeutic services only ............................................................................... 114
M. Patients receiving preoperative evaluations only ........................................................................ 115
N. Ambulatory surgery .................................................................................................................... 115
O. Routine outpatient prenatal visits ................................................................................................ 115
P. Encounters for general medical examinations with abnormal findings ...................................... 115