My primary tells me that i have two herniated discs based on mri(l5,l4). my physiatrist tells me its my facet joint which is the issue. what is it?

Both are right: I don't see why both clinicians can't be right in this case. If you have a herniated disc then the vertebrae will exert more pressure on the articulating surface which is called the facet joint. Over time the act of the bones rubbing on each other will cause bone spurs, arthritis and pain. You seem a little young for all that. Good luck :)

There are many : findings on a lumbar MRI that may or may not have any bearing.on your true diagnosis which is usually made on a careful and complete physical examination & with a detailed history with any tests &/or imaging studies often obtained to confirm the diagnosis. Generally, no studies even needed as most respond to 6 weeks of treatment.

Can have both: Disc deterioration or damage leads to increased load on the spinal facet joints between each vertebra, so both are associated. The psychiatrist can confirm by x-ray or other imaging which might be most important

Can be both: degeneration of the discs can be associated with facet changes also and it is challenging to isolate the cause of pain in this situation.

Need some procedures: Both conditions could coexist together.There are procedures to differentiate one from the other such as EMG,PE and facet joint inyections,if the facet inyection relieves the pain this is the source and is not you thik more about the disc herniation