4A12XM4Monitoring of Cardiac Stress, External Approach
- Billable / Specific Code
4A12XM4 is a billable ICD-10-PCS procedure code for Monitoring of Cardiac Stress, External Approach. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027). The root operation Monitoring involves determining the level of a physiological or physical function repetitively over a period of time. The Alphabetic Index lists this code under Stress test. In AHRQ's Clinical Classifications Software (CCSR), this procedure falls under Cardiac stress tests.
Code Identity
PCS Table Breakdown
Each ICD-10-PCS code is built from seven characters, each an axis of the procedure. Hover or tap the icons for the official CMS definitions.
| Position | Designation | Value | Meaning |
|---|---|---|---|
| 1 | Section | 4 | Measurement and Monitoring |
| 2 | Body System | A | Physiological Systems |
| 3 | Operation | 1 | Monitoring |
| 4 | BodySystem | 2 | Cardiac |
| 5 | Approach | X | External |
| 6 | Function/Device | M | Total Activity |
| 7 | Qualifier | 4 | Stress |
In the ICD-10-PCS Alphabetic Index
The FY 2027 ICD-10-PCS Alphabetic Index refers to 4A12XM4 as Stress test. These index entries lead to this code:
To code stress test, open the FY 2027 ICD-10-PCS Alphabetic Index at Stress test. The entry lists 4A12XM4 directly as a complete, billable code.
Clinical Classification (CCSR)
AHRQ groups this procedure code into these clinical categories.
Convert to ICD-9-PCS
Closest ICD-9-PCS equivalents for this code under the General Equivalence Mappings.
Similar Procedure Codes
Questions About 4A12XM4
Is 4A12XM4 a billable code?
Yes. This is a complete seven-character ICD-10-PCS code, specific enough to report Monitoring of Cardiac Stress, External Approach on inpatient claims from October 1, 2026 through September 30, 2027.
What is the ICD-10-PCS code for stress test?
The ICD-10-PCS Alphabetic Index lists Stress test under code 4A12XM4, Monitoring of Cardiac Stress, External Approach, billable on inpatient claims in fiscal year 2027.
What do the characters in 4A12XM4 mean?
The code breaks down character by character: the 1st character 4 is the Section (Measurement and Monitoring); the 2nd character A is the Body System (Physiological Systems); the 3rd character 1 is the Operation (Monitoring); the 4th character 2 is the BodySystem (Cardiac); the 5th character X is the Approach (External); the 6th character M is the Function/Device (Total Activity); the 7th character 4 is the Qualifier (Stress).
What is the ICD-9-PCS equivalent of 4A12XM4?
Under the General Equivalence Mappings, Monitoring of Cardiac Stress, External Approach crosswalks to ICD-9-PCS 89.41 (Cardiovascular stress test using treadmill), 89.42 (Masters' two-step stress test), and 89.43 (Cardiovascular stress test using bicycle ergometer). The mapping is approximate, so confirm it fits the documentation.
