2023 ACOS Annual Clinical Assembly of Osteopathic Surgeons

Join us in the windy city this fall for the 2023 ACOS Annual Clinical Assembly (ACA)! This year's ACA will be held September 20-24 at the Chicago Marriott Downtown Magnificent Mile in Chicago, Illinois.

Educational Programming
ACOS is pleased to offer CME-eligible content across the cardiovascular and thoracic, general, neurological, plastic and reconstructive, proctological, and urological surgery disciplines. The 2023 ACA will be accredited for both American Osteopathic Association (AOA) Category 1A continuing medical education (CME) credits as well as AMA PRA Category 1 Credits™. Click here to see this year's schedule and plan your itinerary!


AOBS at the ACA
ACOS is pleased to welcome back and host the American Osteopathic Board of Surgeons (AOBS) at this year's ACA! AOBS will conduct oral exams on-site at the conference on Wednesday, Sept. 20, 2023, in Chicago, Illinois at the Chicago Marriott Downtown Magnificent Mile (540 North Michigan Avenue Chicago, IL 60611).  Those who registered to take their oral exams during the ACOS ACA will receive packets directly from AOBS. These packets will include your schedule. Questions? Contact AOBS at (312) 202-8078.



We are excited to assemble for the 2023 Annual Clinical Assembly (ACA) taking place in Chicago, IL, at the Chicago Marriott Downtown Magnificent Mile. Do not miss this opportunity to take advantage of learning with osteopathic surgeons from across the nation, reunite with old friends, and make new connections!

Registration rates include discipline programming, keynote addresses, access to the exhibit hall, poster presentations, ACOS conclave reception, and more!

Late/Onsite Rate
July 31

Member & Resident Member in Practice - CME Eligible


Resident Member in Training Program - No CME Awarded


Non-Member in Practice - CME Eligible


Non-Member in Training Program - No CME Awarded


Retired Members - No CME Awarded


Student Member


Student Non-Member


Cancellation & Refund Policy:  All cancellations and requests for refunds must be received in writing to [email protected] no later than Sunday, August 20, 2023, and are subject to a 20% cancellation fee.  No refunds will be offered on cancellations made after Sunday, August 20, 2023. Tickets included with the registration fee are non-refundable and there is no discount for unattended banquets and receptions. There are no refunds for "No Shows."

ACA Terms and Conditions: By registering for the 2023 ACA, you agree to the event’s Terms and Conditions, the ACOS Code of Conduct, and any Covid-19 protocol policies.  Please click here to read the 2023 ACA Terms and Conditions and ACOS Code of Conduct.

Registration Questions? Call 800-888-1312 or Email [email protected]

Hotel and Travel Information

We are pleased to host the 2023 Annual Clinical Assembly (ACA) at the JW Marriott Downtown Magnificent Mile. Located in the heart of downtown Chicago, the hotel offers luxury, comfort, thoughtful amenities and exceptional views of the city and Lake Michigan. The hotel is located just steps from the best attractions and entertainment options Chicago has to offer.

ACOS has negotiated discounted room rates for 2023 ACA registrants. Reservations are available on a strictly first come, first served basis. We encourage all participants to reserve their hotel room now as space is limited, and the hotel is sure to fill up quickly!

Chicago Marriott Downtown Magnificent Mile

540 North Michigan Avenue, Chicago, Illinois
(312) 836-0100 | Website

Room Rate

Standard Room

$279/night +Taxes & Fees


Booking your Hotel Room

Online Reservations: Please use the link below to make your reservations for this year's conference. You may click on the link or cut and paste the link into your web browser. This will direct you to a dedicated page that will be pre-loaded with the group rate for the ACOS Annual Clinical Assembly.


Reservations by Phone: 
ACA registrants may also contact the Chicago Marriott Downtown Magnificent Mile Reservations Department directly to book rooms. Once transferred to an agent:
Please reference:   ACOS and provide the hotel name: Chicago Marriott Downtown Magnificent Mile
Reservations:   877-303-0104
Hotel Cut-off: Wednesday, August 30, 2023

Warning: The reservation methods listed on www.facos.org or communicated directly by the ACOS are the officially authorized methods of booking your room at the host hotel for the 2023 Annual Clinical Assembly of Osteopathic Surgeons. Please beware of fraudulent organizations offering rooms at a significant discount.  Attendees may be lured by highly attractive rates but could fall prey to imposters causing a loss of deposits, be charged hidden fees, or bait and switched to hotel rooms they never booked. Do not give them your credit card information. These companies are in no way affiliated with the Annual Clinical Assembly of Osteopathic Surgeons, the ACOS, the AOCPr or the Chicago Marriott Downtown Magnificent Mile.