Does anyone have any documentation in regards to the differences between these two codes? We have a provider who states that he believes he should be using the 94375. However, in the progress notes we usually see measurements such as 300/350/300. Wouldn't it be appropriate then to use the S8110, peak expiratory flow rate (physician services)? I appreciate any clarification or documentation that can be provided and if possible e-mailed to me at so I can present this information to our provider. Thanks!