If you have a Lowrance unit and have your waypoints saved on a SD card is there someway to import those way points onto a Hummingbird unit?

Not directly to a Helix or number series.
What file type did you export as?
What Humminbird unit do you want to load the data to?

File USR. Not sure as far as which Humminbird unit to load onto. The reason I ask is because I currently have a Lowrance HDS 12 Gen 3 and as a crappie fisherman I have a ton of brushpiles saved on a SD card, eventually I think I want to switch over to a Humminbird but not ready to do so just yet.

They will auto convert from Lowrance to Humminbird on the Humminbird Onix and Solix....

With free GPS Babel program should be straightforward

SD card in computer
Open .usr file with gps Babel and convert the file to humminbird format saving it on the card
Put card in humminbird unit and upload waypoints from the humminbird file you made with gps babel

If you get a Helix or discontinued model with a number name, you load to the data to HumminbirdPC computer software that you will get in your account when you register the unit/s.
For those units, the data has to be in a MATRIX folder that HBPC creates when you copy the file to the memory card.
HumminbirdPC will translate a USR file to GPX.

As long as the Humminbird unit supports the GPX format, you can just export them from the Lowrance unit in that file format.

One caution, check the waypoint names. If any are longer than the Humminbird format has room for, have any with spaces or symbols in the names, they will be corrupt for use and may cause unit operation issues.

I received a .usr file with over 900 waypoints to review and had to edit about 1/2 of them. Still have some that cause a pop-up warning when opening that file in HBPC. Since I am not using any of them, I am not concerned about it.