NSTAR Gas Company (Eversource Energy) Rate Selection Guide
NSTAR Gas Company, operating under the Eversource Energy brand, distributes natural gas to roughly 239,000 customers across eastern Massachusetts. Delivery service is regulated by the Massachusetts DPU, while gas supply is open to competitive suppliers under the state's deregulated gas market.
NSTAR Gas Company (Eversource Energy) Rate Schedule Comparison
| Schedule | Type | Rate | Best For |
|---|---|---|---|
| G-40/G-41 General Service | Commercial | Customer charge + volumetric distribution (per DPU tariff) | Small to mid-size businesses |
| G-50/G-51 Large C&I | Commercial | Customer charge + tiered distribution (per DPU tariff) | Large commercial / high-load-factor |
| Default Supply (GAF) | Supply | Seasonal Gas Adjustment Factor per therm | Customers not shopping for a supplier |
Market Overview
NSTAR Gas distribution service is regulated by the Massachusetts DPU, but gas supply is competitive. C&I customers can buy the commodity from licensed competitive suppliers while NSTAR Gas continues to deliver, read meters, respond to emergencies and bill. Default-supply customers pay the DPU-approved Gas Adjustment Factor.
Need to pull your actual usage data to compare rates? See the NSTAR Gas Company (Eversource Energy) Data Access Guide →
Current Rate Schedules
NSTAR Gas bills separate a regulated distribution (delivery) charge — set by the Massachusetts DPU and including a fixed customer charge plus volumetric distribution charges — from a supply (gas commodity) charge that is either the DPU-approved Gas Adjustment Factor or a competitive supplier's price. Effective November 1, 2025, the DPU approved new delivery rates that raised delivery charges roughly 24-28% versus the prior period (about a 13% increase on the total bill for a typical customer). Specific per-therm C&I delivery and customer-charge figures are published in NSTAR Gas's currently effective tariff filed with the DPU; the structure is described qualitatively here because verified per-unit C&I figures were not published on a public rate page.
Effective: November 1, 2025 · Full Tariff Book →
| Schedule | Type | Applicability | Structure | Rate |
|---|---|---|---|---|
| G-40 / G-41 General Service – Small C&I | commercial | Small and medium commercial and industrial gas customers. Used by businesses with moderate annual consumption. | Fixed monthly customer charge plus volumetric distribution charge per therm; supply charge billed separately as the DPU-approved Gas Adjustment Factor or a competitive supplier's rate. Per-unit figures per the DPU tariff. | Per DPU tariff (structure-only; verified per-therm figure not publicly posted)+ Not applicable for general service classes |
| G-50 / G-51 General High-Load-Factor / Large C&I | commercial | Larger commercial and high-load-factor industrial customers with higher annual gas consumption. | Fixed customer charge plus tiered/declining-block volumetric distribution charge per therm; commodity supply separate. Per-unit figures per the DPU tariff. | Per DPU tariff (structure-only)+ May apply for high-load-factor classes per tariff |
| Large General Service (Interval-Metered, e.g. GV/LG) | industrial | Large industrial and institutional customers with interval-capable meters and high annual throughput. | Fixed customer charge plus volumetric distribution charge; eligible for Energy Profiler Online interval data. Per-unit figures per the DPU tariff. | Per DPU tariff (structure-only)+ Per tariff for applicable interval classes |
| Default Gas Supply (Gas Adjustment Factor) | commercial | C&I customers who have not selected a competitive supplier; commodity supplied by NSTAR Gas. | Pass-through commodity charge per therm set by the DPU-approved Gas Adjustment Factor, recalculated periodically (typically seasonally). No utility markup. | Seasonal GAF per therm (see DPU Gas Supply/GAF filings)+ Not applicable |
Rate Recommendations by Use Case
Small to mid-size business (G-40/G-41)
A typical commercial account on the general service class should focus on competitive supply procurement, since delivery is fixed by tariff.
General service classes carry a fixed customer charge plus volumetric distribution; the controllable cost is the deregulated supply price.
- Lock a fixed competitive supply rate to hedge winter volatility
- Verify you are on the correct general service class for your usage
- Pull 36 months of bills to baseline seasonal consumption
Large / high-load-factor industrial (G-50/G-51, interval-metered)
High-consumption industrial sites should combine competitive procurement with interval-data analysis and rate-class optimization.
Larger classes use tiered distribution and may benefit from high-load-factor treatment; interval data via EPO supports efficiency.
- Enroll in Energy Profiler Online for load-shape visibility
- Negotiate competitive supply with a fixed or indexed structure
- Reassess rate class annually as consumption changes
Multi-site portfolio / energy manager
Portfolios should centralize data via EDI or an aggregator and run a coordinated procurement strategy across sites.
Aggregated, normalized data across accounts enables benchmarking and bulk supplier negotiation.
- Use EDI 867 or an aggregator (Nectar/UtilityAPI) for normalized data
- Benchmark therm/usage intensity across sites
- Coordinate supply contract renewals to a common cycle
Historical Rate Trends
NSTAR Gas delivery rates are set in periodic DPU rate cases; the supply portion (GAF) changes seasonally with wholesale gas markets. The most significant recent change was the DPU-approved delivery increase effective November 1, 2025.
November 1, 2025
DPU approved new NSTAR Gas delivery rates, increasing delivery charges roughly 24-28% versus the prior period — about a 13% increase on the total bill for a typical customer.
+24% to +28% (delivery)Overall trend: Delivery charges have risen significantly, with a major increase effective November 2025. Supply (GAF) fluctuates seasonally with wholesale natural gas prices.
Next expected change: Seasonal GAF resets; next delivery change subject to future DPU rate proceedings
Cost Optimization Strategies
Because Massachusetts gas supply is deregulated, NSTAR Gas C&I customers can manage cost through competitive supplier procurement, load/usage analysis, and selecting the correct rate class. Delivery charges are fixed by tariff and not negotiable.
Competitive Supplier Procurement
For: All C&I customers
Shop the deregulated supply market and lock a fixed or indexed commodity price with a licensed competitive supplier, rather than defaulting to the seasonal Gas Adjustment Factor.
Rate Class Verification
For: Commercial & industrial
Confirm the account is on the most economical applicable rate class (e.g., G-40/G-41 vs. G-50/G-51) given annual consumption and load factor.
Interval Data Analysis via EPO
For: Large C&I with interval meters
For interval-metered accounts, use Energy Profiler Online to identify load patterns and efficiency opportunities that reduce overall therm consumption.
To implement these strategies, you need your 15-minute interval data. Learn how to download NSTAR Gas Company (Eversource Energy) interval data →
Deregulated Market Shopping
Gas supply is competitive in Massachusetts. C&I customers can choose a licensed competitive supplier for the commodity portion of their bill while NSTAR Gas continues to deliver the gas and issue the bill. Customers who do not choose a supplier receive default supply at the DPU-approved Gas Adjustment Factor.
How to Compare NSTAR Gas Company (Eversource Energy) Suppliers
- 01Review your current rate class and annual therm usage from recent bills
- 02Compare licensed competitive suppliers and their fixed vs. indexed offers
- 03Confirm the supplier serves your NSTAR Gas service area and customer class
- 04Enroll with the chosen supplier; NSTAR Gas continues delivery and billing
Contract Terms for NSTAR Gas Company (Eversource Energy) Supply Agreements
- Fixed-price terms (commonly 6-24 months)
- Indexed/variable-price options tied to market
- Check term length, renewal and early-termination clauses
Common Pitfalls When Shopping NSTAR Gas Company (Eversource Energy) Rates
- Variable rates can spike after an introductory period
- Watch for automatic renewal and termination fees
- Delivery charges are unaffected by supplier choice — only the supply charge changes
- Verify supplier licensing with the Massachusetts DPU
Frequently Asked Questions
Can my business choose its own natural gas supplier from NSTAR Gas?▾
Yes. Massachusetts gas supply is deregulated, so C&I customers can buy the gas commodity from a licensed competitive supplier. NSTAR Gas still delivers the gas, reads the meter, and sends the bill — only the supply charge changes. Customers who do not choose a supplier receive default supply at the DPU-approved Gas Adjustment Factor.
How does a third party or consultant get my NSTAR Gas usage data?▾
Authorize them with the Eversource Customer Information Release Form, or use a data aggregator (Nectar, UtilityAPI) that connects to Eversource on your behalf — for Nectar, see docs.nectarclimate.com. Suppliers and trading partners can also exchange usage via EDI 867. Standard portal bills are PDF; structured exports come through these channels.
Does NSTAR Gas offer interval (15-minute) gas data or Green Button?▾
Green Button is not available for NSTAR gas data (it exists only for Eversource MA electric). Interval gas data is available only to customers with interval-capable meters (e.g., GV/LG classes) through Energy Profiler Online, and it is non-billing quality. Most C&I accounts have monthly therm data.
What changed with NSTAR Gas rates on November 1, 2025?▾
The Massachusetts DPU approved new delivery rates effective November 1, 2025, increasing delivery charges roughly 24-28% versus the prior period — about a 13% increase on the total bill for a typical customer. Specific per-therm C&I figures are in the currently effective tariff filed with the DPU.
What does EDI support look like for gas suppliers?▾
NSTAR Gas supports ANSI X12 Version 4010 EDI for suppliers and trading partners, covering 814 (enrollment/change), 867 (usage), 810 (invoice) and 820 (remittance). New suppliers must sign a Gas Supplier Service Agreement, set up VAN or point-to-point connectivity, and complete testing before going live.
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