ICD-9-CM and CPT coding update
By Therese M. Jorwic, MPH, RHIA, CCS, CCS-P
Asthma is a condition so common (it affects 25 million Americans) that offices see it often as either a first-listed or secondary diagnosis.
It’s a chronic disease, and the classic symptoms are wheezing, chest tightness, shortness of breath, and coughing, especially early and late in the day.
With asthma, the airways react to various substances. They become inflamed, and the muscles around them tighten and cause them to narrow. In response, they create more mucus, which narrows them even more. It can occur at any time, and the symptoms can range from mild to a severe attack.
Here’s look at the coding. And as usual, we are looking at ICD-9-CM as well as ICD-10-CM.
Asthma and ICD-9-CM
In ICD-9-CM, asthma falls into the 493 category. And there are fourth digits to identify the type:
493.0 – extrinsic asthma. This is asthma caused by environmental allergens such as dust or smoke.
493.1 – intrinsic asthma. This is non-allergic asthma. It’s caused by immunological response to chemicals such as smoke or to stress, food, or exercise.
493.2 – chronic obstructive asthma. This is asthma with COPD, and it includes chronic asthmatic bronchitis. COPD does have its own code (496), but it’s a sort of last-resort code that’s used only if the documentation shows no more than the COPD.
493.8 – Other forms of asthma. And here there are two fourth-digit options.
First is 493.81, which is for exercised-induced bronchospasm. This is a spasmodic contraction of the smooth muscles of the bronchi, and it and sometimes occurs in children playing sports.
It can be occur with asthma as well as with other respiratory conditions such as bronchitis, and when that’s the case, it is not coded separately but within the codes for the condition. However, if the documentation doesn’t show any other diagnosis, use code 519.11 (acute bronchospasm). That code shows it is not associated with anything else.
The second fourth-digit option is 493.82 for cough-variant asthma. It says the only symptom is a dry chronic cough lasting eight weeks or more.
493.9 – other and unspecified. Because asthma is chronic, it can affect the treatment of other conditions such as heart problems. In that case, it gets coded as unspecified.
Plus some fifth digits
ICD-9-CM also has fifth digits that are used with extrinsic, intrinsic, chronic obstructive, and unspecified asthma. They are
0 – unspecified.
1 – with status asthmaticus. Status asthmaticus is an acute attack that is not relieved by the usual treatments such as bronchodilators or adrenaline. The condition is serious and usually requires hospitalization.
2 – with acute exacerbation. Exacerbation means the attack carries severe wheezing and shortness of breath that does respond to drugs or treatment.
What if there is both status asthmaticus and acute exacerbation? Code the most severe condition, which is the status asthmaticus.
And now for asthma and ICD-10-CM
In ICD-10-CM, the respiratory codes begin with the letter J, and asthma is found in the J45 category.
J45 includes allergic asthma, allergic bronchitis, hay fever, and so on.
It also includes both extrinsic and intrinsic asthma. Those aren’t separated out as in ICD-9-CM because the terms have fallen by the wayside. The change simply shows the terminology providers now use.
There is also a note saying to use an additional external cause code to tell how tobacco fits into the picture. There are codes for environmental and occupational exposure, exposure during the perinatal period, a history of use, and tobacco dependence and use.
Excludes notes too
Pay attention too to the excludes notes. In ICD-10-CM there are two types of excludes. Exclude 1 is for things that don’t occur at the same time as the coded condition. And Exclude 2 is for things that are not part of the condition but that the patient could have at the same time and thus can be coded separately.
For asthma, the Exclude 1 (or never use with) group carries things such as detergent asthma, lung diseases due to external agents, and miner’s asthma.
Exclude 2 (or can be coded separately) lists asthma with COPD (J44.9), chronic asthmatic obstructive bronchitis (J44.9), and chronic obstructive asthma (J44.9). So if the patient has asthma plus COPD, there will be a J45 code plus a J44.9 code.
Other differences
Another ICD-10 difference is that asthma is subcategorized according to the frequency of occurrence:
J45.2 – mild intermittent (≤ 2 times a week)
J45.3 – mild persistent (> 2 times a week)
J45.4 – moderate persistent (daily)
J45.5 – severe persistent (throughout the day)
J45.9 – other and unspecified
The J45.9 codes are divided into two groups.
The first, unspecified (J45.90), includes asthmatic bronchitis, childhood asthma NOS, and late onset asthma. A sixth character then shows if there is an exacerbation or status asthmaticus or if the condition is uncomplicated. The asthma NOS code defaults to uncomplicated.
The second, other (J45.99), includes exercise induced bronchospasm (J45.990), cough variant asthma (J45.991), and any other specified form (J45.998).
Therese M. Jorwic, MPH, RHIA, CCS, CCS-P, is assistant professor of health information management at the University of Illinois at Chicago and senior consultant for MC Strategies in Atlanta.
