Report 20552/20553 once, regardless of the number of injections.
Example of 20553: patient falls off a roof and reports pain in the RT trapezius, LT trapezius, and RT sacroiliac muscles. All 3 are injected. You've just reported 3 or more muscles but billing 20553 ONE time.
Below is also a FAQ from a reliable source.
Trigger-Point Injections
Q. What code(s) should I submit when I perform trigger-point injections at an office visit?
A. You should submit 20552, "Injection(s); single or multiple trigger point(s), one or two muscle(s)," or 20553, "... three or more muscles." The code is based on the number of muscles injected, not the number of injections given. Note that you should only submit 20552 or 20553 once per session since either code covers multiple injections. Also note that you should clearly document the location of injections, number of injections and number of muscles involved. If you also perform a significant, separately identifiable E/M service at the same visit, you should attach modifier -25 to the appropriate E/M code
~Hope this is helpful. Rebecca~
