First, it is ALWAYS better if you tell us the CPT code (you did), AND the diagnosis code, AND the denial code, AND the denial description, AND the licensure level of the provider when discussing denials. That way we have all of the information to give good advice.
Having said that, here is my first impression: 99308 is nursing facility care, and is not the most specific code you could use. Use a mental health code, as these are not specific to place of service.
I do not bill for FQHC, so I do not know if that matters in this scenario.