Superbills: ICD-9 vs. ICD-10
To show the added complexity that providers will face when using ICD-10-CM, the Blue Cross
Blue Shield Association converted a superbill from ICD-9-CM to ICD-10-CM.
Important things to understand from this exercise:
- A superbill is a form used by medical practitioners and clinicians so they can quickly
complete and submit the procedure(s) and diagnosis(s) for a patient visit for reimbursement.
It is generally customized for a provider office and contains patient information, the
most common CPT (procedure) and ICD (diagnostic) codes used by that office, and a section
for items such as follow-up appointments, copays, and the provider’s signature.
- Blue Cross Blue Shield Association started with a model superbill created by the American
Academy of Family Practitioner’s practice management journal, Family Practice
Management (FPM). The back of the superbill shows 164 ICD-9 diagnosis codes identified
by FPM as being those most commonly used by family physicians.
- About half of the 164 ICD-9 codes on the superbill are general codes such as "unspecified" or "not
otherwise specified." These general codes exist so that all information encountered
in a medical record can be assigned a code. While they lack the specificity necessary
to infer diagnosis details, they are often used on superbills due to space limitations.
Continuing their use in ICD-10 will only further prevent realization of the code set’s
- CMS has published "Generalized Equivalency Mappings" or "crosswalks" that
relate every ICD-9 code to one or more ICD-10 codes. We used these crosswalks to convert
each ICD-9 code on the superbill to its equivalent ICD-10 code or codes.
- In some cases the CMS crosswalks were incomplete or possibly inaccurate, and conversion
to ICD-10 actually produced far less clinical detail than had been provided
by the original ICD-9 code. In these few instances we tried to provide an equivalent
mapping, while still using more general ICD-10 codes as is typical with superbills. For
- The AAFP superbill includes the ICD-9 codes for "845.00 Sprained/strained
ankle, unspecified". The CMS crosswalk maps this to two codes: 1) "S93.409A
Sprain of unspecified ligament of unspecified ankle, initial encounter," and
2) "S93.409D Sprain of unspecified ligament of unspecified ankle, subsequent
encounter."However, this is incomplete because it does not include a code
for a strained ankle. Therefore, we added 1) "S96.919A Strain of unspecified
muscle and tendon at ankle and foot level, unspecified side, initial encounter;" and
2) "S96.919D Strain of unspecified muscle and tendon at ankle and foot level,
unspecified side, subsequent encounter."
- The AAFP superbill includes the ICD-9 codes for "919.0 Abrasion, unspecified"; "924.9
Contusions, unspecified"; and "919.4 Insect bite". The CMS crosswalk
simply maps these to either of two catch-all ICD-10 codes, "T07 Unspecified
multiple injuries" or "T14.90 Unspecified injury of unspecified body
region".Such general diagnosis codes submitted by a provider would be insufficient
to determine the medical necessity of a procedure. We therefore listed the most
residual ICD-10 codes available for each injury type*,
e.g. "S90.519A Abrasion, unspecified ankle; Initial encounter".
* Note that there is no single residual ICD-10 code for an
Abrasion, Contusion, or Insect bite, respectively—instead, one can only choose among
a number of codes for each injury type such as "Abrasion of [particular body part]".