There is a lot of focus on how the ICD-10-CM is different from the ICD-9-CM and many are feeling nervous about the change. I thought to help calm some anxiety and to provide a clearer picture, that this post would focus on things that are going to stay the same during the transition.

General:

The ICD-10-CM is the replacement of the ICD-9-CM volumes I and II. The ICD-10-CM is still divided into two main portions: the alphabetic index and the tabular index. Codes are still looked up in the alphabetic index and additional digits are still verified in the tabular. There is still a table of drugs and chemicals for poisonings, a neoplasm table, and an external causes index.

Structure will remain in a similar fashion as well. Guidelines and conventions are located in the front of the manual. General guidelines are listed first and then chapter specific guidelines and listed next. Codes are still broken down by classifications and anatomical locations and placed into chapters with three digit categories and multiple digit subcategories.

Chapters and categories still progress by following the loose structure by listing codes effecting the outside of the body first and progressing inward, and listing codes effecting from the top of the body and moving down.

Example: Integumentary codes are listed before musculoskeletal codes (outside of the body inward) and codes regarding the head are generally listed before codes regarding the shoulders (top of the body down). 

Conventions:

Many of the coding conventions that we are familiar with will stay the same and transition from the ICD-9-CM to the ICD-10-CM. Items that will remain include:

1)      Brackets [ ] indicating “code first”

2)      Parentheses ( ) providing “non-essential modifiers”

3)      Colons :

4)      NEC

5)      NOS

6)       “Includes” notes

7)      Inclusion terms

8)      “Classified Elsewhere”

9)      “Code also” or “use additional code”

10)   “Code first”

11)   “in dieses classified elsewhere”

12)   The term “and” can still be interpreted as “and/or”

13)   When with or without are the two options for the final character the default for with is either fifth or sixth digit “1” and for “without” the fifth digit “0” or sixth digit “9” is the default.

14)    “see” and “see also”

General Guidelines:

1)      Signs and symptoms that are associated routinely with a disease process are still not coded in addition to the diagnosis, and signs and symptoms that are not usually associated are still coded in addition.

2)      The “ABC” rule: Acute conditions are still coded before chronic conditions

3)      Multiple codes for a single condition are still coded using the same rules, using “additional codes” as secondary assignments and “code first” codes as primary assignments.

4)      Combination codes that describe two diagnosis under a single code still exist

5)      Late effect codes (sequel) are still utilized under the same general guidelines

6)      Impending and threatening conditions are coded under the same guidelines

Miscellaneous

General coding rules like “if it’s not written and legible in the medical record by the physician that it didn’t happen” will not change when transitioning from the ICD-9-cm to the ICD10-CM.  Codes will still need to be supported by documentation; documentation will just need to be more detailed to meet the needs of the more detailed code sets. Unspecified and not elsewhere specified codes will still be available for use but due to the large availability of codes provided by the ICD-10-CM insurance companies are going to be more skeptical of these code selections and may deny these claims for lack of adjudication.

On a side note: