Coding Multiple Conditions

Vol. 17 •Issue 27 • Page 8
CCS Prep!

Coding Multiple Conditions

Coders must be familiar with combination codes, multiple codes and manifestation coding guidelines.

A coder with any experience knows that coding involves more than merely looking up words and selecting corresponding codes on a one-to-one basis. Coding also requires that the coder review the clinical relationship between the multiple conditions that a patient may have and make code selections based upon that clinical relationship. Many medical conditions are inter-related, and the ICD-9-CM coding system allows the capture of these relationships through the use of several different types of diagnosis codes: combination codes, multiple codes (whether mandatory or discretionary) and the related manifestation codes. Each will be discussed.

A combination code is used to report two diagnoses or one diagnosis that is associated with a secondary condition. Combination codes are located in the ICD-9-CM alphabetic index as subterms that follow connecting words such as “due to,” “with,” “associated with” or “in.” The coder may also be able to locate combination codes by reading inclusion and exclusion notes in the tabular list. The new coder may ask, “How do I know when to assign a combination code?” The answer is through thorough coding and paying attention to all coding instructions. The coder then becomes familiar with the types of conditions that require combination codes. Some are more readily apparent than others: acute cholecystitis with cholelithiasis should be assigned to code 574.00 instead of reporting separate codes of 575.0 and 574.20. The combination code is present in the alphabetic index as follows:

Cholelithiasis with cholecystitis acute 574.0

The fifth digit of 0 is added after ascertaining that no obstruction was present.

But some combination codes are not so straightforward and may involve conditions that are clinically and inherently related. For instance, when chronic renal failure and hypertension are both documented on a patient record, the coder may be tempted to assign the very common codes 585.X and 401.9. But the ICD-9-CM Official Guidelines for Coding and Reporting (section I.C.7.a.3) indicates:

“Assign codes from category 403, Hypertensive chronic kidney disease, when conditions classified to categories 585 Ð 587 are present. Unlike hypertension with heart disease, ICD-9-CM presumes a cause-and-effect relationship and classifies chronic kidney disease (CKD) with hypertension as hypertensive chronic kidney disease.”

Note that this guideline involves chronic renal failure only, and if acute renal failure and hypertension are present without documentation of co-existing chronic kidney disease, the conditions are reported separately with codes from the 401 and 584 categories.

Another example of the appropriate assignment of a combination code in lieu of separate, more commonly reported codes involves chronic obstructive pulmonary disease (COPD) and asthma. Coding Clinic, 2nd Quarter, 1990, page 20 includes the following:

“The new code 493.2x, Chronic obstructive asthma, was developed because of the need to distinguish between non-obstructive and obstructive asthma (that in chronic obstructive lung disease), within the classification. When a patient has COPD with asthma, there is continuous obstruction to airflow on expiration, unlike a patient with non-obstructive asthma, where the patient wheezes during an asthma attack, but then returns to normal breathing once the attack subsides. When a diagnosis of asthma is documented with COPD, 493.2x is assigned whether or not the physician states ‘chronic obstructive’ asthma.”

Multiple coding involves the use of more than one code to fully describe the components of a particular disease process or complex diagnostic statement. When combination codes are not available, but the documentation includes terms such as “due to,” “with,” “secondary to” or “incidental to,” multiple codes should be assigned to most fully describe the conditions.

Multiple coding can be considered mandatory or discretionary. Mandatory multiple coding is designated in the alphabetic index by the use of the second code in brackets, which designates the manifestation code. The first code reflects the main underlying condition, and the second code identifies the manifestation of that main condition. Both of these codes must be assigned, and they must be sequenced in the order specified. In the tabular list, the coder will know that another code is required because the terminology “use additional code” appears with the main code and “code first underlying condition” appears with the manifestation code. Regardless of the circumstances of the admission, a manifestation code can never be sequenced as a principal or first-listed diagnosis. If submitted to a Medicare fiscal intermediary, or to another payer that follows national coding guidelines, the case will not be reimbursed until another code is sequenced as the principal or first-listed diagnosis.

For example, a patient with bleeding esophageal varices is admitted to a hospital for treatment of the varices. The documentation indicates that the varices are due to cirrhosis of the liver. The alphabetic indexed entry appears below:

Varix esophagus bleeding in cirrhosis of liver 571.5 [456.20]

This indicates that the code for the cirrhosis (571.5) must be sequenced first and the manifestation (the varices, code 456.20) must be sequenced as a secondary condition. This is considered mandatory multiple coding.

Discretionary multiple coding involves assigning multiple codes only if the additional condition is documented as actually being present. The coding instruction in the tabular list is “use additional code,” which then instructs the coder to look for the presence of the condition in the medical record documentation before assigning an additional code.

A common example is a urinary tract infection due to E.coli infection. Under code 599.0 in the tabular list, the following appears: “Use additional code to identify organism, such as Escherichia coli [E.coli] (041.4).” This specific type of organism will not be present on all cases, but the coder is alerted to look for documentation of an underlying organism that is causing the infection and assign a separate code accordingly.

Another common coding scenario involves guidelines for cases in which terminology for both “acute” and “chronic” are documented. Whether or not both are coded depend upon the alphabetic indexed entries for that term. For example, a coder may commonly see “acute and chronic bronchitis” documented. The indexed entry appears below:

Bronchitis acute or subacute 466.0 chronic 491.9

If separate subterms for acute or subacute and chronic are listed at the same indentation level in the index, both conditions are coded, with the code for the acute condition sequenced first. In this particular example, both the acute and the chronic conditions appear at the same indentation level so both would be assigned, with code 466.0 sequenced first. Conversely, if a patient has acute and chronic poliomyelitis, the indexed entry appears as below:

Poliomyelitis (acute) (anterior) (epidemic) 045.9 chronic 335.21

When only one term is included in the index as a subterm, and the other is in parentheses as a nonessential modifier (after the main term), only the code listed for the subterm is assigned. In this case, only code 335.21 would be assigned.

Multiple coding is also required for cases involving patients with late effects, which are residual conditions that remain after the end of the acute phase of an injury or illness. There is no time limit for when a late effect code can be assigned, but coders should review documentation carefully to ensure that the physician makes the connection between the current condition and the fact that it is due to the previous, but now healed, original condition. The nature of the late effect is sequenced first, with the code for the late effect sequenced second.

Many conditions related to previous trauma are inherently late effects, such as fracture nonunion or malunion. Others may not be as readily apparent, such as neural deafness from childhood measles. The vast majority of late effects require two codes for appropriate coding, unless the alphabetic index or tabular list directs otherwise. Also, when the late effect code has been expanded to the fourth- or fifth-digit level that includes the specific late effects for the residual conditions, only the cause of the late effect code is assigned. A good example of this is the late effect of cerebrovascular disease (438.0-438.9) category.

It should be noted that although reporting multiple codes to fully describe an episode of care is necessary, indiscriminate multiple coding is not appropriate. An example involves assigning secondary codes for signs and symptoms that are an inherent part of a definitive diagnosis that has already been coded. If a patient is admitted for treatment of congestive heart failure (CHF) and has an associated pleural effusion that is not addressed during the admission, it would not be appropriate to assign a secondary diagnosis for pleural effusion on the same case. Likewise, assigning codes solely on the basis of lab or other tests that have not been substantiated by a physician is not allowed. This is especially crucial when assigning codes under the new MS-DRG system, whereby finding CC or MCC conditions may be more difficult than it was under the previous CMS DRGs.

Coders should not assign codes for conditions that are considered incidental findings and have no significance for the current episode of care. For example, atelectasis on a chest X-ray or right bundle branch block on an EKG is not unusual, and unless the physician documents the significance of the finding and how it relates to the current episode of care, it should not be coded.

To brush up on the ICD-9-CM Official Guidelines for Coding and Reporting referenced above, please review the following:

A. Conventions for the ICD-9-CM

6.Etiology/manifestation convention (“code first,” “use additional code” and “in diseases classified elsewhere” notes)

B. General Coding Guidelines

9.Multiple coding for a single condition

10.Acute and Chronic Conditions

11.Combination Code

12.Late Effects

After you’ve completed your review, check yourself with the quiz below.

1. A patient is seen in the physician’s office with a diagnosis of chondrocalcinosis of the shoulder due to calcium pyrophosphate. Which of the following would be the appropriate diagnosis code(s) selection?

a. 275.49, 712.21

b. 712.11, 275.49

c. 712.21, 275.49

d. 275.49, 712.81

2. A patient is admitted to the hospital with an admitting diagnosis of GI bleeding. Underlying chronic conditions include hypertension, S/P MI, COPD, atrial fibrillation and asthma, all of which are currently treated. After GI endoscopy, diverticulitis of the colon is diagnosed as the cause of the bleeding. Which of the following would be the appropriate diagnosis code(s) selection?

a. 578.9, 562.11, 401.9, 412, 496, 427.31, 493.90

b. 562.13, 401.9, 412, 496, 427.31, 493.90

c. 562.13, 401.9, 412, 493.20, 427.31

d. 578.9, 562.11, 401.9, 412, 493.20, 427.31

3. The patient is seen in the ambulatory surgery center for treatment of a scar contracture of the left hand secondary to a burn that was suffered during the previous year. Which of the following would be the appropriate diagnosis code(s) selection?

a. 944.00, 709.2

b. 709.9, 944.00, 709.2

c. 709.2, 906.6

d. 906.6, 709.2

4. An elderly patient is admitted to the inpatient unit of the hospital with shortness of breath and fever. She is found to have influenza and pneumonia and is treated accordingly. She also has flaccid hemiplegia due to an old CVA. Which of the following would be the appropriate diagnosis code(s) selection?

a. 487.1, 486, 438.20

b. 486, 487.1, 438.20

c. 487.0, 438.20

d. 487.0, V12.59

5. A patient was admitted with a diagnosis of subacute and chronic pyelonephritis. He has underlying conditions that include diabetic retinopathy, COPD and a traumatic arthritis of the ankle, S/P ankle fracture 2 years ago. Which of the following would be the appropriate diagnosis code(s) selection?

a. 590.00, 590.80, 250.50, 362.01, 496, 716.17, 905.4

b. 590.10, 590.00, 250.50, 362.01, 496, 716.17, 905.4

c. 590.80, 250.51, 362.01, 496, 716.17, 824.8

d. 590.10, 590.00, 250.51, 362.02, 496, 716.17, 905.4

This month’s column has been prepared by Cheryl D’Amato, RHIT, CCS, director of HIM, and Melinda Stegman, MBA, CCS, clinical technical editor, Ingenix (, which specializes in the development and use of software and e-commerce solutions for managing coding, reimbursement, compliance and denial management in the health care marketplace.

Coding Clinic is published quarterly by the AHA.

CPT is a registered trademark of the AMA.

Answers to CCS Prep!: 1. a: The underlying condition (the calcium pyrophosphate problem) is sequenced first, and then the chondrocalcinosis is sequenced second. The instruction note in the tabular list under code 712.2X indicates, “Code first underlying disease (275.4);” 2. c: Combination codes are assigned for the colon diverticulitis with bleeding (562.13) and for the COPD and asthma (493.20).; 3. c: Following the late effect guidelines, the code for the residual condition (the scar) is sequenced first, and the code for the late effect itself is sequenced second. The burn happened during the previous year and is no longer considered acute; it should not be coded separately.; 4. c: Combination codes are assigned for the influenza with pneumonia (487.0) and the hemiplegia late effect of a CVA (438.20); and 5. b: Both subacute and chronic pyelonephritis codes are listed at the same indentation level in the index and so both are coded, with the acute code sequenced first. The diabetes is not specified as Type I, nor is the retinopathy specified as proliferative, so codes 250.50 and 362.01 should be assigned. The ankle fracture is no longer acute, so code 824. 8 should not be assigned at this time. Assign codes 716.17 for the traumatic arthropathy and 905.4 to represent a late effect of an ankle fracture.

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