In most cases yes, the IBS sensor on most BMWs has gone through many revisions. If the part you are replacing is the factory part, then you will most likely need the adaptor.
The adaptor's job is to allow the updated IBS connector to work seamlessly with the factory harness of your vehicle. Most IBS leads will look something like this:
If you'd like to know which parts fit your specific BMW, please enter your vehicle information on fcpeuro.com underneath "Select your Vehicle". Simply enter your Year, Make, Model, Submodel, and applicable trims. Once your car is selected at fcpeuro.com, our catalog is automatically filtered to show parts that fit your specific car.
Once your car is added to the selector, there are a couple of important ways that we advise correct fitment.
The first is the "fitment indicator" shown on the Product Page after selecting a part. This box is below the "add to cart button" and has two states. It will either say " Yes this part fits" or "Part may not fit, click to verify".
Sometimes the green box will be accompanied by extra fitment notes. These notes may be independent of the information gathered by the vehicle selector. IE: VIN-specific options, need to be taken into account when determining overall fitment.