Michael P. Ast, MD

Hospital for Special Surgery · New York, NY 10021-4823

AAHKS member

Fellowship: Adult reconstruction — Hospital for Special Surgery, 2013¹
In practice: 13 years since fellowship
2024 Medicare: 184 joint replacements²
Medicare: Opt-out on file through 2027-01-01
AAHKS: Member — directory-listed as of 2026-08-18

1 hss.edu · 2026-08-20 2 CMS claims — a lower bound

What this record establishes

The authenticated AAHKS directory lists this surgeon as a member, and CMS published hip or knee replacement services under this surgeon's NPI.

What still needs verification: board certification. An unmet criterion is never a finding against a surgeon: CMS publishes only the Medicare half of a practice, and a credential nobody has documented is unknown, not absent.

How each fact was established

Joint-replacement fellowship verified

Adult reconstruction fellowship — Hospital for Special Surgery, 2013. Read on the cited page.

The official profile states that michael p ast completed adult reconstruction fellowship training at Hospital for Special Surgery.

Review the fellowship source ↗

Years in practice

13 years since fellowship

Review the experience source ↗

Joint replacement volume

184 primary hip and knee replacements were published under this NPI in 2024 Original Medicare fee-for-service claims (56 hip, 128 knee). That is a lower bound: cash and commercially insured cases are published nowhere, for anyone. Above the 100 the criterion asks Medicare to show, the unpublished half is assumed to at least match it, which is how the 200-a-year criterion is credited: half counted, half assumed.

Medicare participation: CMS opt-out record found

The CMS opt-out file reports an effective period of 2025-01-01 through 2027-01-01. The separate 2024 claims count is historical and may predate or overlap this opt-out period.

Opt-out status is not evidence of retirement, fellowship training, surgical volume, or quality.

AAHKS membership

Listed in the authenticated AAHKS member directory as Fellow Member.

Board certification

American Board of Orthopaedic Surgery certification is not covered by the retained dataset and has not been checked.

Is this your record?

A surgeon may correct their own page. Sign in as a physician, confirm the NPI on this record, and verify with a code texted to your cell phone. You can then correct the practice, fellowship and start-year fields, or ask for the page to come down. Corrections appear here as stated by you, beside what the public sources show.

Report an error in this record

Anyone may report an error: a patient, a practice, a colleague, or the surgeon. A person reads every report and checks it against a source before anything on the page changes. You can also write to privacy@sherlockhealth.ai.

This is a documented record, not a rating or a recommendation. It carries no stars, scores, ranks or badges. Every fact names its source and the date it was read; a fact nobody has documented reads “not yet documented,” which is a gap in the record and never a finding about the surgeon. Whether a surgeon is right for you is decided in an examination, by you and them.

Sources

What this record stands on

Consolidated dataset generated 2026-08-24; CMS participation data updated July 31, 2026; each read source carries its own date above.