1. Diagnostic Coding: ICD-10-CM
CHAPTER 4
Diagnostic Coding: ICD-10-CM

2. Chapter 4 Diagnostic Coding: ICD-10-CM
See the ten-step Revenue Cycle figure (at the beginning of the chapter).
This chapter focuses on the following steps:
Preregister patients
Establish financial responsibility
Check in patients
Review coding compliance
Review billing compliance
Check out patients
Prepare and transmit claims
Monitor payer adjudication
Generate patient statements
Follow up payments and collections

3. Learning Outcomes (1)
When you finish this chapter, you will be able to:
4.1 Discuss the purpose of ICD-10-CM.
4.2 Describe the organization of ICD-10-CM.
4.3 Summarize the structure, content, and key conventions of the Alphabetic Index.
4.4 Summarize the structure, content, and key conventions of the Tabular List.

4. Learning Outcomes (2)
When you finish this chapter, you will be able to:
4.5 Apply the rules for outpatient coding that are provided in the ICD-10-CM Official Guidelines for Coding and Reporting.
4.6 Briefly describe the content of Chapters 1 through 21 of the Tabular List.
4.7 Assign correct ICD-10-CM diagnosis codes.
4.8 Differentiate between ICD-9-CM and ICD-10-CM.

5. Key Terms (1) acute Alphabetic Index category chief complaint (cc)
chronic
code
coexisting condition
combination code
convention
default code
diagnostic statement
eponym
etiology
excludes 1
excludes 2
exclusion notes
external cause code
first-listed code
GEMs
ICD-9-CM
ICD-10-CM

6. Key Terms (2) NOS (not otherwise specified)
placeholder character (x)
primary diagnosis
principal diagnosis
sequelae
seventh-character extension
subcategory
subterm
Table of Drugs and Chemicals
Tabular List
Z code
ICD-10-CM Official Guidelines for Coding and Reporting
inclusion notes
Index to External Causes
laterality
main term
manifestation
NEC (not elsewhere classifiable)
Neoplasm Table
nonessential modifier

7. 4.1 ICD-10-CM (1) Used to code and classify morbidity (disease) data
U.S. federal government ICD-10-CM clinical modification (CM) codes describe conditions and illnesses more precisely than WHO’s ICD-10
Mandated for diagnoses under HIPAA Electronic Health Care Transactions and Code Sets standard beginning October 1, 2015
Expertise in diagnostic coding requires knowledge of medical terminology, pathophysiology, and anatomy, as well as experience in correctly applying the guidelines for assigning codes

8. 4.1 ICD-10-CM (2) ICD-10-CM Code Makeup
Code—three- to seven-character alphanumeric representation of a disease or condition
Category has three-character code
Subcategory has four- or five-character code
When available, sixth and seventh characters are REQUIRED
Updates called addenda are available on government website
New codes must be used when they go into effect

9. 4.2 Organization of ICD-10-CM (1)
Two major parts (with subsections):
Alphabetic Index – part of ICD-10-CM listing diseases and injuries alphabetically with corresponding suggested diagnosis codes (see Figure 4.1)
Neoplasm Table – summary table of code numbers for neoplasms by anatomical site (and divided by the description of the neoplasm)
Table of Drugs and Chemicals – index in table format of drugs and chemicals listed in the Tabular List
Index to External Causes – index of all external causes of diseases and injuries classified in the Tabular List
Tabular List – part of ICD-10-CM listing diagnosis codes in chapters alphanumerically (see Figure 4.2)

10. 4.2 Organization of ICD-10-CM (2)
Process of assigning ICD-10-CM diagnosis codes:
In the medical documentation, find the main reason the patient is receiving care
In the Alphabetic Index, find the description of the condition and proposed (suggested) code
In the Tabular List, look up the proposed code, and study any conventions (notations/rules) to guide you in selecting the right code
This process (including verifying in the Tabular List) must be followed when assigning all codes

11. 4.2 Organization of ICD-10-CM (3)
Diagnostic statement – physician’s description of the main reason for the patient encounter; begins the process of assigning ICD-10-CM codes
Convention – typographic technique that provides visual guidance for understanding information

12. 4.3 The Alphabetic Index (1)
Alphabetic Index is organized by condition, not body part
Main Terms, Subterms, and Nonessential Modifiers
Main term – word that identifies a disease or condition in the Alphabetic Index
Default code – ICD-10-CM code listed next to the main term in the Alphabetic Index that is most often associated with a particular disease or condition
Subterm – word or phrase that describes a main term in the Alphabetic Index
Etiology – cause or origin of disease or condition (or a description of a particular type or body site for the main term)
Nonessential modifier – supplementary word or phrase that helps to define a code in ICD-10-CM

13. 4.3 The Alphabetic Index (2)
Common terms – similar names for the same condition (example = flu, influenza)
Eponym – name or phrase formed from or based on a person’s name (example = Hodgkin’s disease)
Turnover lines – term is too long to fit on one line (indented farther to the right than subterms)
Cross-references—“see” and “see also” indicate further information is available

14. 4.3 The Alphabetic Index (3)
Not elsewhere classifiable (NEC) – abbreviation indicating the code to use when a disease or condition cannot be placed in any other category (if disease or condition is not listed/classified in the code book)
Not otherwise specified (NOS) – term that indicates the code to use when no information is available for assigning the disease or condition a more specified code (if disease or condition is not completely described/specified by the provider in the medical record documentation)

15. 4.3 The Alphabetic Index (4)
Multiple Codes, Connecting Words, and Combination Codes
Manifestation – characteristic sign or symptom of a disease
Typical signs, symptoms or secondary process – needs second code indicated by brackets after the term
First-listed code – code for diagnosis that is the patient’s main condition
In cases involving an underlying condition and manifestation, the underlying condition is the first-listed code
Combination code – single code describing both the etiology and manifestation(s) of a particular condition

16. 4.4 The Tabular List (1) The Tabular List is divided into:
Category – three-character code for classifying a disease or condition
Subcategory - four- or five- character alphanumeric code (see Figure 4.2)
Placeholder character (x) - character “x” inserted in a code to fill a blank space (also known as the “dummy placeholder”)
Code – three, four, five, six, or seven alphanumeric characters (starting with a letter)
Seventh-character extension – necessary assignment of a seventh character to a code; often for the sequence of an encounter

17. 4.4 The Tabular List (2)
Inclusion notes – Tabular List entries addressing the applicability of certain codes to specified conditions (indicated by the word “includes”)
Exclusion notes – Tabular List entries limiting applicability of particular codes to specified conditions (indicated by the word “excludes”)
Excludes 1 – exclusion note used when two conditions could not exist together, such as an acquired and a congenital condition; means “not coded here”
Excludes 2 – exclusion note meaning that a particular condition is not included here, but a patient could have both conditions at the same time; means “not included here”

18. 4.4 The Tabular List (3) Punctuation
Colon (:) – indicates an incomplete term
Parentheses ( ) – used around descriptions that do not affect the code
Brackets [ ] – used around synonyms, alternative wordings, or explanations
Abbreviations: NEC and NOS are used in the Tabular List with the same meanings as in the Alphabetic Index

19. 4.4 The Tabular List (4)
Etiology/manifestation coding – notes may include instructions on required use of additional code
code first the underlying disease
Laterality – use of ICD-10-CM classification system to capture the side of the body that is documented; the fourth, fifth, or sixth characters of a code specify the affected side(s)
documents the side of the body (left or right) being classified

20. 4.5 ICD-10-CM Official Guidelines for Coding and Reporting (1)
General rules, inpatient (hospital) coding guidance, and outpatient (physician office/clinic) coding guidance from the four cooperating parties (CMS advisers and participants from the AHA, AHIMA, and NCHS)
Overview of key points: (see Figure 4.3)
Code the primary diagnosis first, followed by current coexisting conditions
Code to the highest level of certainty
Code to the highest level of specificity

21. 4.5 ICD-10-CM Official Guidelines for Coding and Reporting (2)
Breakdown of key point: (see Figure 4.3)
Code the primary diagnosis first, followed by current coexisting conditions
Primary diagnosis – first-listed diagnosis
Coexisting condition – additional illness that either has an affect on the patient’s primary illness or is also treated during the encounter
Acute vs. chronic conditions:
Acute – illness or condition with severe symptoms and a short duration (list acute code before chronic)
Chronic – illness or condition with a long duration
Sequelae – conditions that remain after an acute illness or injury has been treated and resolved

22. 4.5 ICD-10-CM Official Guidelines for Coding and Reporting (3)
Breakdown of key point: (see Figure 4.3)
2. Code to the highest level of certainty
Signs and symptoms—only code if there is no definitive diagnosis
Suspected conditions—do not code unconfirmed diagnoses (“rule out,” “suspected,” “probable,” or “likely”), but code signs and symptoms instead
Principal diagnosis – in inpatient coding, the condition established after study to be chiefly responsible for the admission of the patient
Postoperative vs. primary: if different, the postoperative diagnosis would have a higher level of certainty than the primary diagnosis

23. 4.5 ICD-10-CM Official Guidelines for Coding and Reporting (4)
Breakdown of key point: (see Figure 4.3)
3. Code to the highest level of specificity
Additional characters in a code add to the clinical picture of the patient
Other vs. unspecified—coder must be able to distinguish between not mentioned in the documentation or not specified in the code listing

24. 4.6 Overview of ICD-10-CM Chapters (1)
A00-B99 – Certain Infectious and Parasitic Diseases
C00-D49 – Neoplasms
malignant
benign
uncertain
unspecified
M codes – Morphology (used by pathologists)
D50-D89 – Diseases of the Blood and Blood-forming Organs and Certain Disorders involving the Immune Mechanism
E00-E89 – Endocrine, Nutritional, and Metabolic Diseases

25. 4.6 Overview of ICD-10-CM Chapters (2)
F01-F99 – Mental, Behavioral, and Neurodevelopmental Disorders
G00-G99 – Diseases of the Nervous System
H00-H59 – Diseases of the Eye and Adnexa
H60-H95 – Diseases of the Ear and Mastoid Process
I00-I99 – Diseases of the Circulatory System
J00-J99 – Diseases of the Respiratory System
K00-K95 – Diseases of the Digestive System
L00-L99 – Diseases of the Skin and Subcutaneous Tissue

26. 4.6 Overview of ICD-10-CM Chapters (3)
M00-M99 – Diseases of the Musculoskeletal System and Connective Tissue
N00-N99 – Diseases of the Genitourinary System
O00-O9A – Pregnancy, Childbirth, and the Puerperium
Note: When coding, be careful of zero (0) versus the letter oh (O)
P00-P96 – Certain Conditions Originating in the Perinatal Period
Q00-Q99 – Congenital Malformations, Deformations, and Chromosomal Abnormalities

27. 4.6 Overview of ICD-10-CM Chapters (4)
R00-R99 – Symptoms, Signs, and Abnormal Clinical and Laboratory Findings, Not Elsewhere Classified
S00-T88 – Injury, Poisoning, and Certain Other Consequences of External Causes
V00-Y99 – External Causes of Morbidity
External cause code reports cause of injuries from events such as transportation accidents, falls, and fires; they are not used alone or as first-listed codes
Z00-Z99 – Factors Influencing Health Status and Contact with Health Services (see Table 4.2)
Z codes = used to report encounters for circumstances other than a disease or injury

28. 4.7 Coding Steps Step 1: Review complete medical documentation
Chief complaint (cc) – patient’s description of the symptoms or other reasons for seeking medical care
Step 2: Abstract the medical conditions from the visit documentation
Step 3: Identify the main term for each condition
Step 4: Locate the main term in the Alphabetic Index
Step 5: Verify the code in the Tabular List (do not skip this step!)
Follow conventions; read notes and instructions
Step 6: Check compliance with any applicable Official Guidelines, and list codes in appropriate order

29. 4.8 ICD-10-CM and ICD-9-CM (1)
ICD-9-CM – previous HIPAA-mandated diagnosis code set (covered in chapter 18)
ICD-9-CM vs. ICD-10-CM
Both ICD-9-CM and ICD-10-CM contain Alphabetic and Tabular lists, with the same Coding Steps (section 4.7)
ICD-10-CM provides many more categories for disease and other health-related conditions with higher level of specificity possible than ICD-9-CM
ICD-9-CM has about 14,000 codes
ICD-10-CM has about 70,000 codes

30. 4.8 ICD-10-CM and ICD-9-CM (2) ICD-9-CM vs. ICD-10-CM (continued)
ICD-9-CM has 17 chapters and two supplemental classifications, V codes, and E codes
ICD-10-CM has 21 chapters, and the order of chapters has changed
ICD-9-CM codes are three to five characters, and ICD-10-CM codes are five to seven alphanumeric characters (to reach a higher level of specificity)
GEMs – general equivalence mappings to assist in the transition from ICD-9-CM to ICD-10-CM
*end of presentation*