It is expected that Detailed Project Report (DPR) for the project will be ready by May 2015.
In February 2016 the Bihar cabinet approved DPR of Patna Metro prepared by RITES a budget of ₹16,960 crore and planned to execute under PPP mode by 2021.
The Patna Metro Rail project has got a fresh boost in May 2016 when Union urban development minister M Venkaiah Naidu reportedly assuring Bihar of the Centre’s in- principle approval to the project within a month.
On 3 July 2018 , Bihar chief secretary Deepak Kumar approved the proposed Patna Metro Rail’s revised detailed project report for putting it up before the state cabinet, with revised estimated cost of the project at ₹ 19,500 crore, including land acquisition cost.
On 20 Sep 2018 , RITES has submitted the revised Detailed Project Report (DPR) to the Urban Development and Housing department.
On 25 Sep 2018 , The Bihar cabinet has approved the constitution of “Patna Metro Rail Corporation Ltd (PMRCL)” as special purpose vehicle (SPV) for implementation of the metro rail project in the capital.
On 28 Sep 2018 , Public Finance Committee has approved the Detailed Project Report (DPR) of the Patna Metro Rail Project.
On 9 Oct 2018 , Bihar cabinet has approved the DPR for Patna metro rail project, now it will be sent to the central government for approval.
On 20 Nov 2018 , Central Government approved the DPR for Patna metro.
On 6 Feb 2019 , Patna Metro gets approval from Public Investment Board (PIB).
On 13 Feb 2019 , Union Cabinet approves Patna Metro Rail Project comprising two corridors.
On 17 Feb 2019 : Prime Minister Narendra Modi lays foundation stone for Patna’s first metro rail corridor.
On 4 March 2019 , Patna Metro Rail Corporation Limited formally opened its office at Indira Bhavan.
On 25 Jul 2019 : Patna Metro work to start in three months.
On 23 Aug 2019: Drone survey started and is slated to end on 15 October.
On 4 Sep 2019: DMRC to oversee the project execution. Work to begin by end of year 2019.
On 18 Nov 2019- CEG starts soil testing for Patna Metro.
On 28 Feb 2020 AECOM bags consultancy contract for both corridors for Patna Metro Project.
Jun 2020: Bids opened for 6.1 kms of metro route construction connecting Mahahi Pakri to New ISBT which is part of route 2 of phase-1.
Jul 2020: Tender awarded for constructing metro depot at New ISBT to Quality Buildcon Pvt Ltd.