ICD-10 Cheat Sheet, Part 2: DIY for Physicians

Aug. 7, 2015 / By Rhonda Butler

This blog assumes you have read part 1, so if you haven’t, see you back here in a few minutes. Part 2 is for those of you in specialties where the number of codes has gone up significantly—orthopedists, OB/GYN docs and oncologists—it takes a bit more work to build a cheat sheet of reasonable size. I called it an “interesting challenge” in Part 1 of this blog, but it’s doable.

After accessing the Tabular.pdf (see instructions in part 1), I would recommend you first take half an hour and do an eyeball review of your specialty’s home base chapter without copying or pasting any codes (you might have to review sections of multiple chapters if your specialty doesn’t have a single home base). This will help you see what you are up against, and help you apply the two principles I introduce below.

Then I recommend you do the second session described in part 1 of this blog, and copy and paste to your blank document the super common conditions outside your specialty you like to have on your cheat sheet. This will get you past the blank sheet of paper phase.

To help you think about how you want to construct the main part of your cheat sheet, I am going to only touch on a couple of principles of cheat sheet building for ICD-10. To do this, I am going to use examples from the musculoskeletal system and injury chapters. The increase in number of codes is concentrated in the musculoskeletal system and injury chapters, mainly because additional anatomic site and encounter detail is applied there across these whole chapters. Aside from the ER docs, who typically don’t do their own coding anyway, the orthopedists probably have the biggest challenge in cheat sheet building.

Principle 1: Aim for an 80/20 cheat sheet

Following the 80/20 rule, a cheat sheet will still save you time because 80 percent of the codes you use most are on the sheet, and only the rarer 20 percent are ones you have to look up. In the world of ICD-9, you were probably able to make a cheat sheet that covered 95 percent of the stuff you see in your practice. Make your coverage goal for ICD-10 more modest. The rarer conditions could well double the size of your cheat sheet and defeat the whole purpose, which is making coding for your practice easier and more efficient. For example, many diagnoses pertaining to the joints in ICD-9 did not name the specific joint in the code. In ICD-10 the joint is specified, along with whether it is the right or left where such things apply. So, one code on your cheat sheet under the old system becomes lots of codes in the new.

For example, Felty’s syndrome is one code in ICD-9 and 23 codes in ICD-10. Since Felty’s syndrome is relatively rare, you could probably leave it off your cheat sheet. For conditions you want on your cheat sheet, like osteoarthritis and rheumatoid arthritis, apply the 80/20 rule to anatomic site, and include only codes for sites you see most commonly, like hips, hands, etc.

Principle 2: Take advantage of recurring code patterns

In the injury and musculoskeletal systems chapters, seventh character extensions for all injury codes specify whether the particular visit is an initial encounter for injury, a subsequent visit for aftercare, or a visit to treat a late effect of the injury.

Seventh character extensions are a lot like “required modifiers” that have been automatically applied to the codes. It is much more efficient to list seventh character extensions separately on the portion of your cheat sheet where they apply, with the applicable code range where they are to be used. They are listed separately in the ICD-10-CM book and it saves a lot of space when done this way:

The appropriate 7th character is to be added to each code from category S01

A – initial encounter
D – subsequent encounter
S – sequela

For many of the fracture codes, including pathologic fractures, there are even more detailed seventh character extensions. For example, here are extensions for fractures at the wrist and hand level.

The appropriate 7th character is to be added to each code from category S62

A – initial encounter for closed fracture
B – initial encounter for open fracture
D – subsequent encounter for fracture with routine healing
G – subsequent encounter for fracture with delayed healing
K – subsequent encounter for fracture with nonunion
P – subsequent encounter for fracture with malunion
S – sequela

By simply formatting these “modifiers” as presented in the book, you can reduce the number of wrist and hand fracture codes on your cheat sheet by a factor of six.

And you can go even further. For example, where specific codes exist for left, right, and unspecified, they will be the same across a broad area. You could list this as a modifier, like so:

For the final character of codes in range M00-M65

Right = 1
Left = 2
Unspecified = 9

I will be the first one to admit I have oversimplified both the “interesting challenge” and the solution. Blogs are not famous for being subtle or detailed. But hopefully this information will help you get a draft cheat sheet that is useful for you, because it reflects the way you think and work.

Rhonda Butler is a senior clinical research analyst with 3M Health Information Systems.

So, you’ve got your ICD-10 cheat sheet, but now what?  Get more ICD-10 answers here.