CMS506v7 - Safe Use of Opioids for CY2025 uses a new valueset called - "Opioid Medication Assisted Treatment (MAT)" (2.16.840.1.113762.1.4.1111.177). 

The valueset has a CPT code in the valueset files from VSAC. This CPT code is "HG" (see screenshot from VSAC file below). 

Questions -

1. Is "HG" a CPT code or a modifier to the CPT code? We ask because a CPT code is usually a 5 alphanumeric character code. 

2. Is it appropriate to use this modifier code by itself without an associated CPT code? 

3. Is it appropriate to use the CPT CodeSystem OID for this modifier - 2.16.840.1.113883.6.12, even though no CPT code is being captured?

We would appreciate clarification related to the above questions. Thanks.