Crosswalking and Unspecified Codes in ICD-10 Are Worthy of Extra Attention

Coding Corner

The information provided here applies to Medicare coding. Be sure to check with your Medicare Administrative Contractor (MAC) for additional information and clarification on these and other items. You should also contact your local insurance carriers to determine if private insurers follow Medicare's lead on all coding matters.

Crosswalking and Unspecified Codes in ICD-10 Are Worthy of Extra Attention
Although many of the coding software packages that work with electronic health records (EHRs) crosswalk your ICD-9 diagnosis codes over to ICD-10 diagnosis codes, please do not trust the computer software.  The process of “crosswalking” codes is good in theory, but you as the clinician still need to verify that the diagnosis codes are correct based on the patient’s condition and treatment.
As an example, many providers used ICD-9 code 311, depressive disorder, not elsewhere classified.  Although this was an unspecified code, it was widely used by primary care providers and insurances paid for services with 311 as a co-morbidity or secondary diagnosis.  The crosswalked code for 311 in ICD-10 is F32.9 – major depressive disorder, single episode, unspecified.  Many providers I have worked with are not comfortable with coding these patients with having a major depressive disorder.  Upon review, many are selecting F32.8 – other depressive disorders.
Another diagnosis frequently used is hypertension, unspecified, coded as 401.9 in ICD-9.  In July and August, I had several calls from offices that were getting documentation requests for office visits (levels 4 and 5) that had 401.9 as a primary or secondary diagnosis.  It appeared multiple payers were looking at the medical necessity of physicians billing higher level care codes with an unspecified hypertension diagnosis.  If you crosswalk 401.9 to ICD-10 your code is I10 Essential (primary) hypertension.   The question I would ask is would I11.0 or I11.9, hypertensive heart disease with or without heart failure, be a more appropriate code for some of these patients?  Only you as the clinician would know.

Coding for asthma is another example.  ICD-10 includes four new sub-classifications of asthma: mild intermittent; mild persistent; moderate persistent; severe persistent; and of course, unspecified.  Each sub-classification has sub-codes for uncomplicated, exacerbation and status asthmatics.  Crosswalking the most utilized asthma code from ICD-9, 493.90-asthma, unspecified type, would give you the choice of codes for unspecified asthma, uncomplicated or other asthma.  Did you know there was that much specificity just for asthma?

The old adage, “You do not know what you do not know,” is true with many physicians when it comes to ICD-10 coding.  If you have not looked at a coding book to see what codes exist in the areas that you most commonly code to and that your EHR system crosswalks to, you may be under-coding the diagnosis and treatment of the patient.  As you know, specificity and severity of the patient’s illness is very important for proper reimbursement.  While there have been requests for documentation on unspecified codes (usually those ending with the number 9), Medicare’s revised ICD-10 payment policies, National Coverage Decisions (NCD) and Local Coverage Decisions (LCD) frequently do not include unspecified codes.
I am not suggesting that you read an ICD-10 code book cover-to-cover.  That would be impractical.  I do encourage you to run a report of your top 25 most utilized diagnosis codes and then copy the section pages for one or two of them to review each week.  As a clinician, you will be able to peruse the listings and understand what specificity that section is looking for.  Pay particular attention to any of your top codes that end in the number 9.  Take an extra moment with these and see if there might be a more specific code that would be more appropriate to use.
With the next round of quality and value-based incentives and disincentives just around the corner, your choice of the most appropriate and specific code may make a difference in your scores, and ultimately, your reimbursement.  Take that five minutes for review.  It may be an invaluable use of your time.

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