Beginning in the fourth quarter of 2015, International Classification of Diseases, Tenth Revision, Procedure Coding System (ICD-10-PCS) procedures reported on HCUP records are stored in the data element I10_PRn. In data prior to the fourth quarter of 2015, International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedures reported on HCUP records are stored in the data element PRn.

In the HCUP databases, ICD-10-PCS procedures are represented by alphanumeric codes with a maximum length of 7 characters. The HCUP data elements for ICD-10-PCS procedures are length 7 and may use the letter Z as a placeholder. The codes are left-justified in the HCUP databases. For example, consider the procedure code BB12ZZZ for fluoroscopy of the right lung. There are no decimals in ICD-10-PCS procedure codes.

The original value of the ICD-10-PCS first listed procedure (I10_PR1), whether blank or coded, is retained in the first position of the procedure vector. Starting at the first secondary procedure (I10_PR2), the procedures are shifted during HCUP processing to eliminate blank secondary procedures. For example, if I10_PR2 and I10_PR4 contain nonmissing procedures and I10_PR3 is blank, then the value of I10_PR4 is shifted into I10_PR3. Secondary procedures are never shifted into the first-listed position (I10_PR1).

Procedures are compared to a list of ICD-10-PCS codes valid for the discharge date. Anticipation of or lags in response to official ICD-10-PCS coding changes are permitted for discharges occurring within a window of time (six months before and six months after) around the official ICD-9-CM coding changes (usually October 1). If the procedure contains intermittent blank characters or is zero filled, then the procedure will be considered invalid.

Procedures are compared to the sex of the patient (edit check EPR03) and the patient's age (edit check EAGE05) for checking the internal consistency of the record.

Invalid and inconsistent codes are handled in the following way.