Cardiology Coding Alert

Don’t use I06.0 when the mitral valve is also involved.

ICD-9 and ICD-10 each have a single code for rheumatic aortic stenosis, so the transition to ICD-10 shouldn’t be tough on that front. But you’ll still need to remember to review the instructions with the ICD-10 code to be sure that code is correct for your case.

ICD-9-CM Code

• 395.0, Rheumatic aortic stenosis

ICD-10-CM Code

• I06.0, Rheumatic aortic stenosis

Rheumatic aortic stenosis is narrowing (stenosis) of the heart’s aortic valve. The cause of the stenosis is scarring left from rheumatic fever, an autoimmune response to certain strep infections.

ICD-9 coding rules: If the physician doesn’t specify “rheumatic,” 395.0 is not appropriate. You should instead report 424.1 (Aortic valve disorders). ICD-9 also instructs that if the patient has both mitral valve and aortic valve involvement, you should code 396.x (Diseases of mitral and aortic valves) instead of 424.0 (Mitral valve disorders) and aortic valve code 424.1.

ICD-10 changes: Adapting to I06.0 shouldn’t take much work. ICD-10 offers a one-to-one code match with ICD-9 for rheumatic aortic stenosis. Both codes have the same note indicating they are appropriate for “Rheumatic aortic (valve) obstruction.”

ICD-10 has a similar rule to ICD-9, indicating that if the documentation doesn’t specify “rheumatic,” you should use a code from I35.- (Nonrheumatic aortic valve disorders).

Another similarity to ICD-9 is that ICD-10 instructs you to use a different code range (not I06.-) for aortic valve diseases if there is mitral valve involvement, too. You should instead use the same range ICD-10 instructs you to use if the patient has tricuspid valve involvement in addition to mitral valve disease: I08.- (Multiple valve diseases).

Documentation: If your clinicians’ current documentation habits for rheumatic aortic stenosis are adequate, they shouldn’t need to change for ICD-10. The documentation should indicate whether the condition is rheumatic. Documentation also should specify whether the aortic valve alone is involved. Finally, just like 395.0, I06.0 is appropriate for rheumatic aortic obstruction, so watch for that term in the documentation.

Coder tips: When you create your new coding tools, make the “rheumatic/nonrheumatic/unspecified” rules clear, and refer coders to I35.- for cases not specified as rheumatic. Similarly, highlight that I06.0 is for aortic valve disease only. If other valves are involved, the correct code will be found in the I08.- range.

Remember: CMS has announced Oct. 1, 2015, as the new compliance date for ICD-10. When ICD-10-CM goes into effect, you should apply the code set and official guidelines in effect for the date of service reported. Learn more at www.cms.gov/ICD10/ and www.cdc.gov/nchs/icd/icd10cm.htm#10update.