ICD-9-CM Combination Code Assignment Review Is Necessary for Test Preparation
Patricia Maccariella, RRA, CCS
Both seasoned and new coding professionals know that the assignment of combination codes can at times be very tricky. It is imperative that the ICD-9-CM index be utilized to arrive at accurate combination codes. In addition, all include and exclude notes must be referenced and followed. In this issue of CCS Prep!, we will present some guidelines to follow in the assignment of these codes. In addition, a short quiz is provided to test your knowledge of combination code assignment.
1. In “The Official Coding Guidelines for Coding and Reporting,” developed and approved by the four cooperating parties (American Hospital Association [AHA], the American Health Information Management Association [AHIMA], the Health Care Financing Administration [HCFA] and the National Center for Health Statistics [NCHS]), combination code assignment is addressed in guideline 1.5. This guideline reads:
“A single code used to classify two diagnoses or a diagnosis with an associated secondary process (manifestation) or an associated complication is called a combination code. Combination codes are identified by referring to subterm entries in the Alpha-betic Index and by reading the inclusion and exclusion notes in the Tabular List. A) Assign only the combination code when that code fully identifies the diagnostic conditions involved or when the Alphabetic Index so directs. Multiple coding should not be used when the classification provides a combination code that clearly identifies all of the elements documented in the diagnosis. When the combination code lacks necessary specificity in describing the manifestation or complication, an additional code may be used as a secondary code.”
2. Official guideline 1.6 addresses multiple coding of diagnoses required for certain conditions not subject to the rules for combination codes.
“Instructions for conditions that require multiple coding appear in the Alphabetic Index and the Tabular List. A) Alphabetic Index: Codes for both etiology and manifestation of a disease appear following the subentry term, with the second code in brackets. Assign both codes in the same sequence in which they appear in the Alphabetic Index. B) Tabular List: Instructional terms, such as ‘Code first…,’ ‘Use additional code for any…,’ and ‘Note…,’ indicate when to use more than one code. ‘Code first underlying disease:’ Assign the codes for both the manifestation and underlying cause. The codes for manifestations cannot be used (designated) as principal diagnosis. ‘Use additional code, to identify manifestation, as…’ Assign also the code that identifies the manifestation, such as, but not limited to, the examples listed. The codes for manifestations cannot be used (designated) as principal diagnosis. C) Apply multiple coding instructions throughout the classification where appropriate, whether or not multiple coding directions appear in the Alphabetic Index or the Tabular List. Avoid indiscriminate multiple coding or irrelevant information, such as symptoms or signs characteristic of the diagnosis.
3. Be alert to subterms that follow connecting words such as “with,” “in,” “due to” and “associated with.”
4. Combination codes may not fully describe the condition, and additional codes may be necessary. For example, urinary tract infection complicating pregnancy codes to 646.6X. The additional code of 599.0 is needed to fully describe the condition. Refer to the note listed under category 646.
5. Several Coding Clinic issues address combination coding. Refer to 1986 January-February p.8; 1985 March-April p. 3; 1984 May-June p. 4. Some of the codes used for examples may have changed due to subsequent code revisions.
6. Perhaps the chapters with the most difficult combination code scenarios are the cardiovascular and renal chapters. Many combination code scenarios in these chapters are dependent on the full clinical information presented within the record. Re-view alphabetic index, tabular and all notes regarding the coding of rheumatic heart diseases, hypertension with renal disease and/or congestive heart failure, arteriosclerosis of extremities with symptoms, and cerebral infarctions.
Quiz Your Knowledge
Take the following quiz to test your combination code knowledge. Have fun!
A) Acute cholecystitis with cholelithiasis and choledocho-lithiasis:
1. 574.00, 574.50
3. 575.0, 574.20, 574.50
B) Meningitis due to salmonella infection:
2. 321.8, 003.21
C) Increased episcleral venous pressure due to glaucoma:
2. 365.9, 365.00
D) Hypertensive heart disease with congestive heart failure:
2. 428.0, 401.9
E) Congestive heart failure with hypertension:
2. 428.0, 401.9
F) Hypertensive cardiomegaly
1. 429.3, 401.9
2. 429.3, 402.90
G) Hypertensive nephropathy with hypertensive congestive heart failure:
3. 402.91, 593.9
2. 401.9, 593.9
I) Mitral valve stenosis and aortic valve insufficiency:
1. 424.0, 424.1
J) Mitral valve stenosis with congestive heart failure:
1. 424.0, 428.0
2. 394.0, 398.91
3. 394.0, 428.0
K) Drug dependence on marijuana and cocaine, continual:
2. 304.21, 304.31
L) Antisocial conduct secondary to benzedrine dependence:
1. 312.9, 304.40
M) Acute appendicitis with peritoneal abscess and generalized peritonitis:
2. 540.0, 567.2
N) Urinary tract infection due to candidiasis:
2. 112.2, 599.0
Patricia Maccariella is manager of coding services at United Audit Systems Inc (UASI).