Here's my opinion: If documentation justifies it, I'd say
59 mod but let me show you how I came to this.
Go to cms.gov or just search "CMS NCCI PTP" (PTP means: Procedure to procedure):
https://www.cms.gov/Medicare/Coding/NationalCorrectCodInitEd/NCCI-Coding-Edits.html
You'll see links at the bottom of the page for hospital & for practitioner. You'll also see effective dates (choose the effective date for your DOS.) You'll see at the tail end of the links code ranges. You have 2 codes, 25116 & 64721 so choose this link:
Practitioner PTP Edits v25.2 effective July 1, 2019 (561,060 records) 0001M/36591 – 26992/G0471
You'll see "column 1" codes & "column 2" codes. Column 2 is bundled with column 1 or in other words, it's a component of column 1 and not separately payable except for certain circumstances. This is where the mod indicator column comes in
"0" means
no mod allowed: the code in column 2 is never allowed with the code in column 1
"1" means a modifier is allowed (make sure documentation justifies) this would
usually be your mod 59
"9" mean N/A and this is where your
51 mod would be more likely (of course, depending on payer)
For your example: Use Control/F to do a search for your code, 64721 You'll see the code appears multiple times (there are easier ways to search: export to excel for example) This one happens to come up easily. You'll see 25116 in column 1 & 64721 in column 2 (meaning 64721 is normally bundled with 25116, so if separate would require 59 mod). The modifier indicator of "1" means ncci mod is allowed. (again if documentation proves that they are separate)
AAPC has an article in the knowledge center also: