Regular expressions for HCPCS codes

Since I revisited my old post on ICD code matching, I thought I’d revisit by post on HCPCS codes too. HCPCS stands for Healthcare Common Procedure Coding System, and is pronounced “hick picks.” When most people say HCPCS, they technically mean HCPCS Level II, and that’s what I mean here. The format of a HCPCS code is simple: one letter and four digits. In regex terms, [A-Z]\d{4} Not all letters are used, so you can get more specific and say [A-CEGHJ-MP-V][0-9]\d{4} Some sources say no codes begin with U, but there are currently five codes that begin with U. When I was doing some research on HCPCS codes recently using AI, I was told there is a D code for dentistry, but that was a hallucination. HCPCS codes can also have also modifiers. These consist of a letter and either a letter or digit: [A-Z][A-Z0-9] Not all letters actually appear in modifiers—I, O, W, and Y are missing—so you could be more specific. At the time of writing there are 384 official modifiers. Modifiers are often…