What the Anti-Aging, Regenerative & Functional Medicine Fellowship means for your care. A4M / Metabolic Medical Institute post-graduate training.
The Fellowship in Anti-Aging, Regenerative and Functional Medicine (FAARFM) is an A4M / Metabolic Medical Institute (MMI) post-graduate training program. Dr. Castellano completed the fellowship and is listed in A4M’s public Find a Provider directory with the fellowship badge.
Garden Grove · Mon–Fri 9 AM – 5 PM
What the fellowship actually requires
The fellowship is open to physicians, physician assistants, nurse clinicians, pharmacists, dental surgeons, and chiropractors. Completing the required modules certifies the practitioner to practice anti-aging, regenerative, and functional medicine within their primary specialty without supervision, and qualifies them to sit for ABAARM board certification. The training stack covers advanced hormone work, metabolic and nutritional science, longevity protocols, and the regenerative-medicine territory that isn’t taught in standard residency.
The honest framing on what A4M is
A4M and its fellowship are real, verifiable training programs that have set the curriculum standard in anti-aging medicine for three decades. A4M is a private professional organization — not a member of the American Board of Medical Specialties (ABMS). The fellowship credential is layered on top of Dr. Castellano’s ABMS-recognized ABFM board certification in family medicine; it doesn’t replace it. The combination is the point: orthodox medicine plus the specialized hormone and longevity training, practiced together, by the same physician.
Dr. Castellano’s fellowship credential
A4M’s public profile lists Dr. Castellano with the FAARFM Fellowship badge. His post-nominals on the profile include FAARM, which is the older name for the same fellowship lineage; the program has been renamed periodically (FAARM → FAARFM → most recently Fellowship in Longevity Medicine), but all names refer to the same A4M / MMI post-graduate training program.
Dr. Castellano’s A4M provider profile lives at a4m.com/phillip-castellano-newport-beach-ca.html. For more on the fellowship program itself, A4M’s current fellowship hub is at a4m.com/a4m-mmi-fellowships.html.
One conversation tells you whether this is the right fit.
Call the office to set up a 1-hour consult with Dr. Castellano. Bring whatever bloodwork you have on file — or fresh labs get ordered up front. Either way, you’ll leave with a real read on what’s going on.
Calling after hours? Leave a message — we’ll get back to you the next business day.