The process of constructing codes in ICD-10-PCS is designed to be logical and consistent: individual letters and numbers, called “values,” are selected in sequence to occupy the seven spaces of the code, called “characters.”
In ICD-10-PCS sections 0 through 4, 7, 8, and 9,the fifth character defines the approach—i.e., the technique used to reach the procedure site.
For the following ICD-10-PCS sections Character 5 classifies the following:
- section 5 (Extracorporeal Assistance and Performance) – duration
- section 6 (Extracorporeal Therapies) – duration
- section B (Imaging) – contrast
- section C (Nuclear Medicine) – radionuclide
- section D (Radiation Therapy) – modality qualifier
- section F (Physical Rehabilitation and Diagnostic Audiology) – type qualifier
- section G (Mental Health) – qualifier
- section H (Substance Abuse Treatment) – qualifier.
Instrumentation used to visualize the procedure site is not specified in the Device value—this information is specified in the Approach value. The definitions for each approach are provided below (they can also be found in the ICD-10-PCS Tables and Index*):