2026 Rate Case Filing
Investor Relations | January 2026
Massachusetts Gas distribution companies (Boston
MA Gas service territory
Gas and Former Colonial Gas)
~950,000 gas customers
Approx. 1,600 employees in Massachusetts
Over 11,000 miles of gas mains
Regulated by Massachusetts Department of Public Utilities
Meeting our commitments Key elements of 2026 rate case filingMass Gas Year 1 revenue increase $144M
Allowed Return on Equity (ROE) of 10.25%
Debt/common equity structure of 46.15%/53.85%
Approximately 5-year rate plan (December 2026 to October 2031)
Introduces a new mechanism that enables timely recovery of gas operator safety regulation costs (Gas Safety Regulation Factor, "GSRF")
Includes a Performance Based Rate Mechanism (PBR) providing recovery of core operating and maintenance costs
Earnings sharing mechanism triggered when actual ROE exceeds 100 bps above allowed ROE 50/50 sharing between customer and company; when actual ROE exceeds 200 bps above allowed ROE 75/25 sharing between customer and company
On affordability:
An "essentials-only" rate case that that balances cost
with critically necessary work
New multi-tiered low income discount to address energy burdens and promote rate equity
A refreshed rate design that reduces seasonal volatility for bills
New rates in effect from December 1, 2026
Financing assumptionsSince the start of the current (2021) rate case we have:
Replaced more than 600 miles of aged infrastructure
Reduced over 17,000 metric tons of carbon dioxide emissions
MA GasCost of equity
10.25%
Cost of
debt 4.55%
Weighted average cost of capital
7.62%
Assumed
equity capitalization
53.85%
Invested $3.9bn in system reinforcement, modernization of LNG assets, fulfilling mandated safety regulations, and replacing aged assets.
Customer impactTypical residential gas heating customers will see an average winter net bill increase of approximately:
Boston $24 monthly or 8.4%
Former Colonial $25 monthly or 9.4%
Revenue increase $144m Rate year 1 increase reflects:$82m Physical infrastructure, asset maintenance, technology for customer support and network security
$19m Local property taxes
$20m Investments in skilled workforce to meet increased safety and compliance requirements
Skilled workforce investments
$23m Other operating & maintenance (O&M) increases
CapexFiling includes revenue support for LNG capital investments through a one-time roll-in, as well as revenue support for regulated safety upgrades through the GSRF, in addition to ongoing revenue support for Gas System Enhancement Plans (GSEP) (outside of base rates)
Rate Base to be updated to include all investments
through December 2025 except for CY 2025 GSEP
Infrastructure,
technology and network security
$144m
Other O&M increases
NiMo Electric 7.2%
Mass Elec
8.1%
Mass Gas
8.6%
KEDNY
10.5%
KEDLI 10.6%
11.1%
Local property taxes
16 January 2026
Summer 2026
Proposal filed Evidentiary hearings
$0
Current (2021) AgreementEquity/Debt
(%)
Allowed
RoE
$35.3bn
FY25 Achieved
RoE
November 2026
1 December 2026
Commission order
New rates effective
Mass Gas53/47
9.7% 8.6%
Rate Case / Regulatory History2021 The current rate case became effective October 1, 2021, and was based on historic test year of fiscal year 2020.
A five year rate plan was approved that increased base distribution rates and put in place the Company's first
PBRM.
2018 The previous rate case became effective October 1, 2018, based on a historic test year of calendar year 2016.
The 2018 rate case increased base distribution rates, including funding to modernize IT infrastructure that
supports our core gas distribution operating capabilities.
Important notice
Further information
Angela Broad
Director of Investor Relations M +44 (0) 7825 351918
Tom Edwards
Senior Investor Relations Officer M +44 (0) 7976 962791
Cerys Reece
Investor Relations Manager M +44 (0) 7860 382264
James Flanagan
Senior Manager - Debt IR/ESG Financing M +44 (0) 7970 778952
National Grid plc
1-3 Strand
London WC2N 5EH United Kingdom
investors.nationalgrid.com