Wiki 73221 vs 73218

[sstep]

Hi
We are having some trouble with an MRI of the finger. We had billed it out as 73221 and the insurance company wants it billed as 73218. Could someone help me with the difference between the two codes?
Thank you

 

[Rajebpt]

HI,

The code description is as follows,

73221-MRI of any joint of upper extremity
73218-MRI of upper extremity other than joint

so thumb cannot be coded as joint of the extremity.