Wiki Modifier 29?

[thefosterfarm]

In the October 15, 2008 Family Practice News, an article on Page 22 about "How to Diagnose, Treat Four Common Conditions" has a box of "Musculoskeletal Dos and Don'ts" in it. In that box, the physician who wrote the article states "Do use a 29 modifier. If you diagnose subacromial shoulder pain and do a subacromial joint injection at the smae visit, use a 29 modifier with your CPT code of 20610.......this tells the insurance company that you both diagnosed the subacromial pain and did the injection at the same visit"

I can find no reference anywhere to a modifier 29. Does anyone know what he may be referring to???

Thanks!