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The Challenges of Mapping CPT® to ICD-10-PCS

  • Wednesday, 10 January 2018 10:27
  • Written by 

DoctorSteth2017

 

 

Many organizations map between different US procedure coding systems (CPT®, ICD-9-CM, ICD-10-PCS) for multiple use cases. A common requirement was to map from CPT to ICD-9-CM procedures for analytics. The switchover from ICD-9-CM procedure codes to ICD-10-PCS effective October 1, 2015 has presented a unique challenge to  mapping CPT to ICD-10-PCS, because ICD-10-PCS is very different from ICD-9-CM procedures.  This undertaking can be overwhelming without a clear understanding of the unique features inherent in these two diverse classification systems.  A side-by-side comparison of the 2018 edition of each system as seen below illustrates these differences.

Classification System:

CPT

ICD-10-PCS

Purpose:

Report services performed by physicians and other qualified heath care professionals in outpatient setting

Report hospital inpatient services

Number of codes:

10,177

78,705

Length of codes:

5-characters

7-characters

Modifiers:

2-character modifier(s), where appropriate, reported separately

No modifiers

Structure of codes:

Unique numeric only codes (e.g., 76120) and numeric with 5th-character alpha (e.g., 0001U)

Each character has unique meaning within its position in the code and is assigned depending on intent/type of procedure done

Reuse of codes:

Deleted codes are sometimes reused after 4-5 years with a completely different description

No reuse of deleted codes

Use of eponyms (e.g., Marshall-Marchetti-Krantz) and Latin:

Yes

No

Use of diagnosis in description:

Yes

No

Multiple services/procedures per code:

Yes

No

Multiple anatomic sites per code:

Yes

Use of measurements (e.g., % body surface, simple/extensive, etc.):

Yes

No

Staged procedures:

Yes

No

Conditional statements (e.g., with/without, if performed, when performed):

Yes

No

Approach to procedure included:

Frequently

Yes

Laterality included:

No, use separately reportable 2-character modifier(s), where appropriate

Yes

Anesthesia, laboratory, performance measurements and clinician visits included:

Yes

No

 

These differences mean that mapping from one classification to the other, such as from CPT to ICD-10-PCS, could be one to one (clinically equivalent procedures or potential matches), one to none (ICD-10-PCS does not have a clinically equivalent code) or one to many (being more granular, ICD-10-PCS has many codes that could be a close enough match to the CPT code, and additional information from the patient’s record would be needed to make a choice).  Examples are provided below.

One to One

CPT®

47562

Laparoscopy, surgical; cholecystectomy

PCS

0FT44ZZ

Resection of Gallbladder, Percutaneous Endoscopic Approach

One to None

CPT®

21499

Unlisted musculoskeletal procedure, head

PCS

Null

One to Many

CPT®

12006

Simple repair of superficial wounds of scalp, neck, axillae, external genitalia, trunk and/or extremities (including hands and feet); 20.1 cm to 30.0 cm

PCS

0HQ0XZZ

Repair Scalp Skin, External Approach

PCS

0HQ4XZZ

Repair Neck Skin, External Approach

PCS

0XQ4XZZ

Repair Right Axilla, External Approach

PCS

0XQ5XZZ

Repair Left Axilla, External Approach

PCS

0UQGXZZ

Repair Vagina, External Approach

PCS

0UQJXZZ

Repair Clitoris, External Approach

PCS

0UQMXZZ

Repair Vulva, External Approach

PCS

0VQ5XZZ

Repair Scrotum, External Approach

PCS

0VQSXZZ

Repair Penis, External Approach

PCS

0VQTXZZ

Repair Prepuce, External Approach

PCS

0HQ5XZZ

Repair Chest Skin, External Approach

PCS

0HQ7XZZ

Repair Abdomen Skin, External Approach

PCS

0HQBXZZ

Repair Right Upper Arm Skin, External Approach

PCS

0HQCXZZ

Repair Left Upper Arm Skin, External Approach

PCS

0HQDXZZ

Repair Right Lower Arm Skin, External Approach

PCS

0HQEXZZ

Repair Left Lower Arm Skin, External Approach

PCS

0HQFXZZ

Repair Right Hand Skin, External Approach

PCS

0HQGXZZ

Repair Left Hand Skin, External Approach

PCS

0HQHXZZ

Repair Right Upper Leg Skin, External Approach

PCS

0HQJXZZ

Repair Left Upper Leg Skin, External Approach

PCS

0HQKXZZ

Repair Right Lower Leg Skin, External Approach

PCS

0HQLXZZ

Repair Left Lower Leg Skin, External Approach

PCS

0HQMXZZ

Repair Right Foot Skin, External Approach

PCS

0HQNXZZ

Repair Left Foot Skin, External Approach

 

As you can see, any one of the differences between the classification systems would make the mapping from one to the other difficult. Considering all the variations could make the mapping unwieldy and ineffective. It can be done, however, if clear objectives and heuristics are outlined at the onset of the project, to guide the mapping choices. If you have questions or would like assistance with mapping projects , please contact us .