Colorado substitute teacher provider Tagg Education filed a legal challenge in Denver’s District Court earlier this month against a Colorado Public Employees’ Retirement Association (PERA) policy that mandates substitute teachers must be members of PERA, regardless of whether they are employed by a school district or as an independent contractor of a third-party agency.

PERA sent an email clarification of this policy to all school employers on June 30, 2023, giving employers until July 1, 2024, to bring their employment practices in line with this position.

Tagg is an app-based service that allows users to join its platform and bid for open substitute teaching positions at schools that have contracted with the company. Users are independent contractors, allowing Tagg to opt out of paying PERA contributions or from charging schools an additional fee to cover those contributions.

Attorney Dave Illingworth, a former Woodland Park School District board member, argued in his complaint on behalf of Tagg that “as a result of the announcement of the substitute rule, Tagg has and continues to suffer irreparable harm from lost business opportunities.”

Illingworth also claims that schools that currently have an agreement with Tagg have notified the company that they won’t renew those contracts. “In both cases, those clients have informed Tagg that the PERA substitute rule was a primary reason for discontinuing any business with Tagg.”

While a PERA representative said the organization doesn’t comment on pending legislation, an email sent to school districts in June of 2023 stated that PERA was taking this position because “substitute teachers are being treated inconsistently across schools and districts and are losing out on PERA service credit. Further, there is a negative impact to the School and DPS division trust funds if they are not receiving contributions on all substitute teachers. Finally, classifying substitutes as non-PERA members avoids working after retirement contributions and rules, which has a long-term negative impact on the trust fund.”

Challenges to the PERA policy

Tagg believes the policy violates the Administrative Procedure Act by conflicting with existing statutes, specifically the Colorado Employment Security Act, which provides a statutory framework for determining whether an individual is an employee or an independent contractor.


Illingworth argues that PERA’s policy is a legislative rule rather than an interpretive one because it establishes a norm applicable in all cases. Legislative rules require PERA to allow interested parties to participate in creating the rule, which would also have to be adopted by PERA’s board of trustees. 

Tagg also believes PERA doesn’t have the authority to classify all substitute teachers as employees without considering the specifics of each employment relationship. 

Illingworth asks the judge for a permanent injunction prohibiting PERA from adopting, implementing, or enforcing the substitute rule, an award for reasonable expenses, including attorney fees and costs incurred in prosecuting the case, and “any other relief the court deems just and proper​.”

Tagg, Illingworth and conservative connections

Tagg was founded in January 2018 by Trevor Miller, the son of Brad Miller — a conservative attorney who represents numerous charter schools and school boards across the state, including Woodland Park. Trevor’s co-founder is his cousin Andrew Lundeen, whose father, state Sen. Paul Lundeen, serves on the Senate Education Committee.

Woodland Park School District hired Brad Miller, who has admitted to having a financial interest in his son’s company, as its attorney during Illingworth’s controversial tenure on the board.

Screenshot from a 2018 Conflict of Interested Disclosure signed by Brad Miller.

Miller signed the disclosure so the Colorado Springs school district could contract with Tagg to supply its substitute teachers. 

Tagg nearly benefited from Brad’s connection with other conservative school districts like the Elizabeth School district, located 45 miles southeast of Denver. Elizabeth Superintendent Dan Snowberger hired the senior Miller in 2023 within a month of taking the top job. The two, along with Woodland Park Superintendent Ken Witt, worked together at Education ReEnvisioned BOCES. BOCES stands for Board of Cooperative (Educational) Services. 

While the company conducts background checks on its users, it doesn’t require them to hold a substitute teaching license with the state’s Department of Education. As a result, Tagg can only provide substitute teachers to charter and private schools. 

Earlier this year, the Colorado Department of Education denied the Elizabeth School District’s request to waive the substitute licensure requirement for public schools so the district could employ Tagg users in its schools.

Illingworth also represents Academy School District 20 school board member Derrick Wilburn who has threatened to sue a district parent for public statements she made during a board meeting. Bernadette Guthrie stated that Wilburn’s reading from a library book containing sexually explicit language during a student-led candidate forum with young children in the audience was tantamount to sexual abuse.

Illingworth told the Colorado Gazette, “Mrs. Guthrie’s repeated false accusations have been outrageous and shameful, and she owes an apology not just to Mr. Wilburn, but to all the real victims of sexual abuse that she’s stepping on in her disgraceful attempt to smear an innocent man.”

Guthrie denied her comments amounted to slander and has refused to apologize for what she said.

Illingworth has not returned a request for comment regarding the lawsuit.

CORRECTION: An earlier version of this article indicated PERA’s policy on requiring substitute teachers to be members of PERA was new. Rather, school employers received clarification on an existing policy.