Home Health ICD-9/ICD-10 Alert

Hint: Always verify your alphabetic index findings with the tabular list.

If you're new to home health coding, you may find the gigantic ICD-9 manual daunting. But this hefty volume is a coder's best friend. The following tips will have you nailing down the right diagnosis codes in no time.

At first glance, NOS or "not otherwise specified" or "unspecified" may not seem all that different from NEC or "not elsewhere classifiable" or "other specified," but these notes actually have very different meanings.

"NOS and NEC are opposite instructions," says Trish Twombly, BSN, RN, HCS-D, CHCE, COS-C, director of coding with Foundation Management Services in Denton, Texas.

"NOS essentially means the book has a more specific code to offer but you as the coder don't have the specific information about the patient to choose a more specific code. So you have to settle for an unspecified code," Twombly says.

For example: Take code 427.9 (Cardiac dysrhythmia unspecified). The book offers more specific dysrhythmia codes. But if you don't have more specific information -- such as whether the dysrhythmia is afib or atrial flutter -- you must use the NOS code or unspecified code, Twombly says.

NEC, on the other hand, means that you have more information about the patient than the book has a code to offer, Twombly says.  

For example: Look at 998.59 (Other postoperative infection). The NEC instruction applies to all codes beginning with the category 998, Twombly says. You would use 998.59 to describe a post-op infection when there is no other post-op infection code listed in the manual that more accurately describes the patient's condition, she says.

For example, say your patient has an appendectomy and now the wound is infected. There is no complication code in the manual that describes an infected appendectomy, so even though you know what kind of surgical wound is infected, the book does not have a specific code to describe the situation, Twombly says. So, you must use an NEC code (998.59).

But suppose the patient had a total hip replacement and now it is infected. It would be inaccurate (and considered up-coding) if you listed 998.59 for this patient because there is another code in the book that more accurately describes the patient's condition -- 996.66 (Infection and inflammatory reaction due to internal joint prosthesis), Twombly says.

You'll see NEC or "not elsewhere classifiable" notes in the alphabetic index and in the tabular list. When you see this note in the alphabetic index, it means that a specific code isn't available for the condition you are coding, and directs you to use the appropriate "other specified" code located in the tabular list, according to the Centers for Medicare & Medicaid Services' coding guidelines. These codes, which usually include a fourth digit "8" or a fifth digit "9," are "for use when the information in the medical record provides detail for which a specific code does not exist," CMS coding guidelines explain.

NOS or "not otherwise specified" codes are "for use when the information in the medical record is insufficient to assign a more specific code," CMS guidelines indicate. You'll notice that these codes usually have a fourth digit "9" or fifth digit "0."

As you work through the alphabetic index, you'll find four different types of cross-reference notes: "see," "see also," "see category," and "see condition." Each term requires slightly different action.

The alphabetic index is an index of diseases, symptoms, injuries or reason for an encounter, says Jan McLain, RN, BS, LNC, HCS-D, COS-C, with Adventist Health System Home Care in Port Charlotte, Fla. Upon reviewing this section, it is possible that more than one of the codes listed could apply, she says. So, to further clarify which diagnosis is the most appropriate, you must consult the tabular list.

The tabular list is where you find the details on how to code the condition, McLain says. There is additional verbiage used in this section that helps determine whether the code indicated in the alphabetic index is appropriate.

Caution: "Coders who code only from the alphabetic index will be inaccurate a good portion of the time," says Judy Adams, RN, BSN, HCS-D, COS-C, president and CEO of Adams Home Care Consulting in Chapel Hill, N.C. "Often the alphabetic index will send you to the unspecified code and you need to read all the entries for the code to hone down to your particular circumstances."

Bottom line: Without the tabular list, you would be missing out on the vital details that help you to code with the greatest accuracy. If you choose your code directly from the alphabetic index, you'll be overlooking this information:

Example: Your patient has acute bronchitis and COPD. You look up bronchitis in the alphabetic index and find "bronchitis, acute or subacute, 466.0." If you don't look in the tabular list, you won't see the "EXCLUDES acute bronchitis with chronic obstructive pulmonary disease" notation, which points to the correct code for this patient: 491.22 (Obstructive chronic bronchitis with acute bronchitis).

Example: Code 250.4x (Diabetes with renal manifestations) requires an additional code to identify the manifestation, such as 581.81 (Nephrosis). This instruction is only found in the tabular list.

Bottom line: The alphabetic index will not provide you with all of the information you need to appropriately code a diagnosis.

Example: You have a patient who has had a total hip replacement. You look in the alphabetic index under "aftercare" and find a code for aftercare following joint replacement surgery (V54.81). When you look this code up in the tabular index, you will be advised: "Use additional code to identify the joint replacement site (V43.60-V43.69)."

To appropriately code aftercare following a hip replacement, you need to code V54.81 (Aftercare following joint replacement) with V43.64 (Organ or tissue replaced by other means, joint, hip) as a secondary code. The V43.64 code does not have to follow V54.81 immediately, but should be coded. If you don't include V43.64, there is no indication of which joint was replaced.