Pfizer boosters are supposed to be in resident arms by October 25th. 
See links below.  
DS
CDC Statement on ACIP Booster Recommendations | CDC Online Newsroom | CDC

To: Residential care facilities (nursing homes, assisted living facilities, group homes, and intermediate care facilities)
 From: CDPHE Residential Care Strike Team 
Colorado Department of Public Health and Environment (CDPHE) has amended Public Health Order 20-20, requiring long-term care facilities to schedule COVID-19 booster vaccine clinics before the end of October 2021 for those eligible for the Pfizer booster shot. This eighth amended order went into effect Sept. 27, and will continue to be in effect until further amended or rescinded.
 
By Oct. 25, and in accordance with Food and Drug Administration (FDA) approval and Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices (ACIP) recommendations for any COVID-19 vaccine authorized or approved for a booster dose, each facility that has a population who is eligible for a booster dose shall complete a COVID-19 booster dose clinic for current eligible residents and staff.
 
By Oct. 1, each facility shall schedule a COVID-19 booster dose clinic and communicate the confirmed clinic date and vaccine provider via email to cdphe_covidvax@state.co.us