---
type: "Bill"
title: "Maryland Transit Administration – Conversion to Zero–Emission Buses (Zero–Emission Bus Transition Act)"
description: "Maryland Transit Administration – Conversion to Zero–Emission Buses (Zero–Emission Bus Transition Act)"
jurisdiction: "us/states/md"
legislature: "Maryland General Assembly"
session: "2021"
identifier: "SB 137"
citation: "Maryland SB 137 (2021)"
classification: ["bill"]
subjects: []
status: "enacted"
primary_sponsors: ["Zucker"]
version_count: 3
action_count: 15
vote_count: 2
first_action: "2020-09-15"
last_action: "2021-05-30"
source: "openstates"
source_identifier: "ocd-bill/662b5dbe-ea1e-4f9e-8991-c4fb055831ad"
source_url: "http://mgaleg.maryland.gov/mgawebsite/Legislation/Details/sb0137?ys=2021RS&search=True"
source_hash: "76b43eb8a69b972d680e39dc48a3470405c88e2827a3d4979c23c0f55c3cf501"
vintage: "2026-07-01"
source_snapshot: "https://data.openstates.org/daily/2026-07-01/public.pgdump"
retrieved_at: "2026-07-06"
confidence: "reported"
tags: ["legislation", "bill", "us-md"]
---

# Maryland SB 137 (2021) — Maryland Transit Administration – Conversion to Zero–Emission Buses (Zero–Emission Bus Transition Act)

## Version chain

The bill's text revisions, in order — the diff chain from filing to enrollment.

1. **Chapter - Maryland Transit Administration – Conversion to Zero–Emission Buses (Zero–Emission Bus Transition Act)** (committee substitute) — [source](http://mgaleg.maryland.gov/2021RS/Chapters_noln/CH_693_sb0137t.pdf)
2. **First - Maryland Transit Administration – Conversion to Zero–Emission Buses (Zero–Emission Bus Transition Act)** (committee substitute) — [source](http://mgaleg.maryland.gov/2021RS/bills/sb/sb0137f.pdf)
3. **Third - Maryland Transit Administration – Conversion to Zero–Emission Buses (Zero–Emission Bus Transition Act)** (committee substitute) — [source](http://mgaleg.maryland.gov/2021RS/bills/sb/sb0137t.pdf)

## Votes

- On Third Reading — **45–0** (pass) · upper
- On Third Reading — **101–33** (pass) · lower

## Sponsors

- Zucker — primary (person)

## Timeline

The legislative action history — every referral, reading, and vote.

- **2020-09-15** Pre-filed `introduction`
- **2021-01-13** First Reading Education, Health, and Environmental Affairs and Budget and Taxation `referral-committee`
- **2021-01-06** Hearing 1/28 at 11:00 a.m. (Education, Health, and Environmental Affairs)
- **2021-04-09** Favorable with Amendments Report by Education, Health, and Environmental Affairs `committee-passage-favorable`
- **2021-04-09** Favorable with Amendments { `committee-passage-favorable`
- **2021-04-09** Second Reading Passed with Amendments
- **2021-04-09** Motion Rules Suspend Two Readings Same Day Const/Rule 24 (Senator King) Adopted
- **2021-04-09** Third Reading Passed `passage`
- **2021-04-09** Referred Rules and Executive Nominations `referral-committee`
- **2021-04-10** Rereferred to Environment and Transportation
- **2021-04-12** Favorable Report by Environment and Transportation `committee-passage-favorable`
- **2021-04-12** Favorable Adopted Second Reading Passed `committee-passage-favorable`
- **2021-04-12** Third Reading Passed `passage`
- **2021-04-12** Returned Passed
- **2021-05-30** Enacted under Article II, Section 17(c) of the Maryland Constitution - Chapter 693 `became-law`

## Source

OpenStates / OpenCivicData bulk snapshot [2026-07-01](https://data.openstates.org/daily/2026-07-01/public.pgdump); origin `ocd-bill/662b5dbe-ea1e-4f9e-8991-c4fb055831ad`. Confidence: reported (aggregated from official Maryland legislature records).