Moderus Beta is a partially low-floor tram, available in either one or three sections, with a single or dual direction configuration.

[1][2] In 2009, MPK Poznań ordered 4 trams (with an option for 3 more) from its subsidiary, based on the Moderus Alfa design but in a three-section, single-space configuration.

The tests were conducted because Municipal Transport Company in Łódź [pl] was considering modernizing its trams using the expertise of Modertrans.

[6] The Beta MF is equipped with energy-efficient AC motor technology that facilitates energy recovery and transmission to the traction network.

Additionally, the low-floor section features a retractable platform to assist with the boarding of strollers and wheelchairs.

[38] On 11 March 2013, Modertrans signed a contract with Tramwaje Szczecińskie for the delivery of components and parts for one Moderus Beta tram.

[63] On the same day, a contract was signed for the delivery of components and parts for a second tram, which was also assembled by Tramwaje Szczecińskie.

[64] On October 24, the body of the second Moderus was delivered to Szczecin, and on 19 January 2015, it began passenger service on line No.

[65] In December 2017, Tramwaje Szczecińskie signed a contract with Modertrans for the delivery of components for the assembly of 2 additional trams, with the option to extend the order by 2 more units.

[41] At the end of August 2020, Modertrans won a tender for the delivery of parts for the assembly of two trams with an option for two additional sets of components.

[67] The trams were to be assembled at the Tramwaje Szczecińskie workshops, but due to the COVID-19 pandemic, the work was done by Szczecin staff at the manufacturer's facilities.

[42] The first tram was delivered to the Szczecin Pogodno depot on 14 December 2020,[33][42] and in mid-January 2021, it began passenger service.

[69] The third Beta from this order (the first from the option) arrived in Szczecin on 28 December 2021,[70] and by 1 February 2022, both trams were in service at the Pogodno depot.

[44] In April 2023, a contract was signed for the delivery of components for the assembly of 2 additional bi-directional Betas.

[74] On 27 November 2014, Modertrans signed a contract with Tramwaje Śląskie for the delivery of 12 bidirectional Moderus Beta trams.

[75] On September 19, during the open days of Tramwaje Śląskie, the trams were given the name Skarbek (English: little treasure), which was chosen in a previous passenger vote.

[30] On 8 March 2018, Modertrans signed a contract with Tramwaje Śląskie for the delivery of 10 single-section trams (8 unidirectional and 2 bidirectional).

[48] In February 2020, the first unidirectional tram was ready[78] and began homologation runs in Poznań, after which it was transported to the Katowice depot on the night of March 15/16.

[79] At the end of March, the tram received its homologation certificate,[80] and on April 16, test runs began in the cities of the conurbation.

[21] The first unit was ready in early November and was transported to Łódź for necessary tests prior to receiving its homologation certificate.