1. Mary Jo Bowie MS, BS, AAS, RHIA, RHIT

2. Diagnostic Coding Guidelines
CHAPTER 5
Diagnostic Coding Guidelines

3. Diagnostic Coding Guidelines
The ICD-10-CM Official Guidelines for
Coding and Reporting were developed by:
Centers for Medicare and Medicaid Services
National Center for Health Statistics

4. Cooperating Parties for ICD-10-CM
The following organizations, known as the Cooperating Parties for ICD-10-CM, have approved the guidelines:
American Hospital Association
American Health Information Management Association
Centers for Medicare and Medicaid Services
National Center for Health Statistics

5. Guidelines Four Sections
There are four sections to the guidelines:
Section I—Conventions, General Coding Guidelines, and Chapter-Specific Guidelines
Section II—Selection of Principal Diagnosis
Section III—Reporting Additional Diagnoses
Section IV—Diagnostic Coding and Reporting Guidelines for Outpatient Services

6. Section I
Section I—Conventions, General Coding Guidelines, and Chapter-Specific Guidelines
This section includes guidelines that
address the structure and conventions
and general guidelines and
chapter-specific guidelines.

7. Section II Section II—Selection of Principal Diagnosis
This section includes the guidelines for the
selection of the principal diagnosis for
nonoutpatient settings.

8. Definition of Nonoutpatient Settings
Nonoutpatient settings include:
Acute care
Short-term care
Long-term care
Psychiatric hospitals
Home health agencies
Rehab facilities
Nursing homes
and the like

9. Section III—Reporting Additional Diagnoses
This section includes the reporting of
additional diagnoses that affect patient care
in nonoutpatient settings.

10. Section IV
Section IV—Diagnostic Coding and Reporting Guidelines for Outpatient Services
This section contains the guidelines for
outpatient coding that includes both
outpatient hospital services and provider-
based office visits.

11. General Coding Guidelines
Diagnosis codes are to be used and
reported at their highest number of characters.
Codes that describe symptoms and signs are acceptable for coding when a definitive diagnosis has not been established.
Signs and symptoms that are associated with a disease should not be reported.

12. General Coding Guidelines (cont.)
Additional signs and symptoms that may not be associated routinely with a disease process should be coded when present.
Multiple codes may be needed.
If the same condition is described as both acute (subacute) and chronic and separate subentries exist, code both and sequence the acute condition first.

13. General Coding Guidelines (cont.)
A sequela (late effect) effect is the residual effect after the acute phase of an illness or injury.
Each unique ICD-10-CM diagnosis code may be reported only once for an encounter.
For bilateral sites, the final character of codes in the ICD-10-CM indicates laterality.

14. General Coding Guidelines (cont.)
Principal Diagnosis
A condition established after study to be
chiefly responsible for occasioning the
admission of the patient to the hospital
for care.

15. General Coding Guidelines (cont.)
When two or more interrelated conditions potentially meet the definition of principal diagnosis, either condition may be sequenced first.
When two or more contrasting/comparative diagnoses are documented as either/or they are coded as if confirmed and the diagnoses are sequenced according to the circumstances of the admission.

16. General Coding Guidelines (cont.)
When a symptom(s) is followed by contrasting/comparative diagnoses, the symptom code is sequenced first.
Sequence as the principal diagnosis the condition, which after study occasioned the admission to the hospital, even though treatment may not have been carried out due to unforeseen circumstances.

17. General Coding Guidelines (cont.)
When the admission is for treatment of a complication resulting from surgery or other medical care, the complication code is sequenced as the principal diagnosis.
If the diagnosis is qualified indicating uncertainty, code the condition as if it existed or was established. This is for inpatient cases only.

18. Secondary Diagnoses Guideline
Secondary diagnoses are defined as all
conditions that coexist at the time of
admission, that develop subsequently, or
that affect the treatment received and/or
length of stay. Diagnoses that relate to an earlier episode which have no bearing on the current hospital stay are to be excluded.

19. Outpatient Guidelines
In the outpatient setting, the term “first-listed diagnosis” is used in lieu of principal diagnosis.
List first the code for the diagnosis, condition, problem, or other reason for the encounter/visit shown in the medical record to be chiefly responsible for the services provided.
Do not code uncertain diagnoses.

20. Outpatient Coding Guidelines
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.
Code all documented conditions that coexist at the time of the encounter/visit, and require or affect patient care, treatment, or management.

21. Outpatient Coding Guidelines
For patients receiving diagnostic or therapeutic services only during the encounter/visit, sequence first the diagnosis, condition or problem, or other reason for the encounter/visit shown in the medical record to be chiefly responsible for the outpatient service.
For ambulatory surgery, code the diagnosis for which the surgery was performed.