CASTA is pleased to administer the Ozone Season Transit Grant Program (OSTGP) in Colorado on behalf of the Colorado Energy Office (CEO). The program provides grants to eligible transit agencies in order to offer free transit services for a minimum of thirty days during ozone season.

CASTA and CEO have developed the OZONE SEASON TRANSIT GRANT PROGRAM policy to administer grant funding to eligible agencies. You can read the policy here.

  • Applicant Eligibility: Transit agencies that operate in the state of Colorado that are eligible to receive money under a grant authorized by 49 u.s.c. sec. 5307 or 49 u.s.c. sec. 5311 are eligible to apply for grant funding.
  • Expense Eligibility:
    • An eligible transit agency that receives a grant through CASTA may use the money to cover the costs associated with providing new or expanded free transit services within its service area during ozone season including offering additional free routes or expanding service on routes for which the eligible transit agency currently offers free service.
    • Grant money may be used to replace farebox revenue and to pay for other expenses necessary to implement the program, including expenses associated with an increase in ridership as a result of the program.
    • an eligible transit agency shall not use grant money to offset or replace funding for free transit services that the eligible transit agency offered as of January 1, 2023.

Application Opens: April 12th, 2023

Application Deadline:

  • For programs starting free transit service June 1, 2023: May 12th, 2023 is the last day to apply.
  • If you plan to start your program later in June or ozone season, please reach out to us to discuss.

Application Process

  1. To apply for a grant, applicants can submit a completed Ozone Season Transit Grant Application Form
  2. Once an application is submitted, CASTA staff will review the application for completeness and to remove any deficiencies.
  3. If there are no deficiencies remaining, the application will be reviewed by OSTG Workgroup. The OSTG Workgroup provides final approval for grant awards.
  4. Individuals will be notified in writing, by email, of approval with an Ozone Season Transit Grant Award Letter and Agreement.

Receiving Grant Funds

The Ozone Season Transit Grant Program is a reimbursement grant. This means that grantees will submit expenses for reimbursement using the Ozone Season Transit Grantee Subgrantee Reimbursement Form.

  • Subgrantees will complete only one Subgrantee Reimbursement Form upon completion of their program period.
    • Subgrantees participating during the standard ozone season between June and August will complete the Subgrantee Reimbursement form by October 6th, 2023.
    • Subgrantees participating during the ozone season established in their application will complete the Subgrantee Reimbursement form within 45 days of the completion of their program period.

CASTA has also created the Subgrantee Reimbursement Uniform Guidance in an effort to provide support subgrantees when they go to submit their reimbursements.


If you have any questions regarding this program please contact us.

Program Director: Joseph Parks | | 303.839.4197