Have you ever looked at your code book and felt like you needed help decoding it? You're in good company!
This will be an ongoing series about specific details in the code books that students often ask questions about or overlook. Today's entry is about ICD-10-CM codes and the difference between NOS and NEC.
NOS (not otherwise specified) or "unspecified" means that the coder does not have any additional details on the type, body part, etc. for the condition being coded. In other words, the code book is offering you more specific options, but you don't know which, if any, might apply because the medical professional didn't document any of them.
NEC (not elsewhere classified) or "other specified" means that the coder DOES have more information, but the code book doesn't have a separate option for that extra information.
In other words, NOS is used when the code book has more options than the coder has information for, and NEC is used when the coder has more information than the code book has options for!
This time in decoding the code book, we're looking at ICD-10-CM pregnancy codes.
Did you know that ICD-10-CM has its own definition of the differences between abortive outcome (abortion), preterm labor, and labor? Even if the physician documents a different term, coders need to use the ICD-10-CM definitions when coding. These definitions aren't easily located in the guidelines, however.
*If a pregnancy ends at less than 20 weeks of gestation, it is classified in ICD-10-CM as an abortion/abortive outcome.
*Onset of labor at 20 weeks up to less than 37 completed weeks of gestation is preterm labor.
*At 37 weeks, labor is considered to term.
These time frames are a good item to pencil into your ICD-10-CM book in the Chapter 15 guidelines for easy reference later, especially during certification exams!
An easily mixed-up set of instructions in the ICD-10-CM code book is the exclusion notes in the Tabular Index. What’s the difference between Excludes1 and Excludes2?
When you see “Excludes1,” the code book is telling you that the additional codes listed cannot be used on the same patient chart as the code you were looking up originally. These codes are mutually exclusive. Think Highlander: "There can be only 1."
When the note says “Excludes2,” it is telling you that the additional codes listed are not considered to be inherently part of the original code you were looking up. If any of those additional conditions are also in the patient's chart, be sure to use a separate code to cover both conditions. In other words, it's saying, "A 2nd code may be needed."
Here's another round of decoding the code books! What the heck are modifiers and where do you find them?
Modifiers are 2-digit tags that can be added to the end of CPT or HCPCS codes to provide details that aren't covered by the original codes, mostly to help smooth along the reimbursement process. They can be 2 letters, 2 numbers, or a letter and a number. Not all CPT or HCPCS codes will require modifiers. More than one modifier can be used on the same CPT or HCPCS code when appropriate to fully capture everything you need to include.
For instance, if an operation requires two surgeons be present, there's a difference in how they are paid if they are each primary surgeons working on separate parts of the operation vs. if one is assisting the other surgeon. When the surgeons' bills are sent to the insurance company, they may use the same procedural (CPT or HCPCS) code, but add the appropriate modifier(s) to show their role in that procedure, so the insurance company knows they aren't being double-billed for that patient, and each surgeon gets the appropriate reimbursement for their role.
Modifiers can also specify certain body parts when the procedural code isn't detailed enough, such as exactly which fingers were involved or whether an eyelid being repaired is upper or lower, left or right.
So where do you find modifiers? Well, the short answer is "in the CPT and HCPCS code books," but it can get a little tricky! The CPT codes have their own set of modifiers, and HCPCS has their own set, and some HCPCS modifiers can be used on CPT codes as well.
In the AMA Professional Edition CPT book, you'll find a short list just inside the front cover. It's good for double-checking the meaning of a modifier you see used, but it only provides very brief descriptions of each modifier there. The fully detailed descriptions of each can be found in Appendix A, near the back of the book. In the HCPCS, where exactly you find them will depend on which publisher's book you are using. PMIC has them in Appendix A, near the back of the book. Optum puts them in Appendix 2, roughly halfway through the book.
We took a bit of a break on these, but we're back now and decoding more of the CPT code book!
You may have noticed that some of the CPT codes have a symbol in front of the code number, but do you know what those symbols are for? There is a small key at the bottom of almost every page, as well as a longer explanation in the Introduction at the front of the book, but let's focus on one of the more common symbols - the #.
When you see # in front of a code, it means that code is out of sequence. The CPT codes are usually listed in numerical order (first 1, then 2, then 3, and so on!), but sometimes a code was split into two or more options or a completely new code was added, and the next number for where it needs to go has already been assigned to something else. An unused number from somewhere else in the chapter will be assigned for the new code, but it will actually be listed where it would make most sense in context rather than in numerical order.
For example, codes 27047, 27048, and 27049 were assigned for tumor excisions of specific different depths in the skin or soft tissue of the pelvis and hip. Then someone decided the size of the excision needed to be accounted for as well. Each of those original three codes is for an excision under 5 cm in size. But what about the excisions that are 5 cm or larger? Codes 27043, 27045, and 27059 were conscripted for this purpose. So now we see these listed in the code book in this order:
27047
# 27043
27048
# 27045
27049
# 27059
What if you already have the code, and you just need to make sure the text matches what you're using it for? If you're starting with the code rather than the condition, you don't need to know in advance whether it was resequenced! You'll start off looking in the numerical order, and the code book will tell you where to look next.
For instance, if you look up 27059, you'll find this message underneath 27057:
"27059 Code is out of numerical sequence. See 27041-27052"
This tells you that it's been moved to somewhere within that code range, so you'll start at 27041 and work toward 27052, looking for 27059. Or if it's more convenient, I suppose you could start at 27052 and work backward toward 27041!