What “modified gross” actually means
Every commercial lease answers one question: who pays the building's operating expenses — property taxes, insurance, common-area maintenance (CAM), utilities, janitorial, repairs? A gross lease says the landlord does (out of a higher rent). A triple-net lease says the tenant does (on top of a lower rent). A modified gross lease splits the list. There is no statute or industry rule for where the line goes; it is whatever the two parties negotiated. Two buildings across the street from each other can both advertise “modified gross” and mean different things.
What the tenant usually pays in a modified gross lease
- Base rent — quoted per square foot per month or per year in California listings.
- Its own utilities — separately metered electricity and gas for the suite is the most common carve-out.
- Janitorial for its own space — the landlord cleans the common areas, the tenant cleans its suite.
- Interior repairs — lighting, plumbing fixtures, and sometimes HVAC service within the premises.
- Increases over a base year (in some MG leases) — the landlord covers taxes, insurance, and CAM up to what they cost in the first year; the tenant pays its share of anything above that.
The landlord typically keeps property taxes, building insurance, structural and roof repairs, and common-area costs. If a “modified gross” lease passes through taxes and insurance in full, it is functionally closer to NNN — read the expense clause, not the label.
A worked example
Say a 2,000-square-foot office is quoted at $2.75 per square foot per month, modified gross. Base rent is $5,500 a month. Under the lease the tenant also pays its own electricity (say $350 a month), its own suite janitorial ($200 a month), and its pro-rata share of operating-expense increases above the base year (zero in year one, perhaps $0.10 per square foot per month by year three, or $200). All-in the space costs about $6,050 a month in year one and roughly $6,250 by year three before annual rent escalations — not $5,500. A competing full-service quote at $3.00 ($6,000 all-in, with utilities and janitorial included) is closer than the headline rates suggest, and a $2.25 NNN quote with $0.70 in NNN charges ($5,900 plus utilities and janitorial) may cost more. Only the all-in monthly number for your square footage is comparable across listings.
Modified gross vs. full-service gross vs. NNN
| Full-service gross | Modified gross | Triple-net (NNN) | |
|---|---|---|---|
| Base rent level | Highest | Middle | Lowest |
| Taxes & insurance | Landlord (increases over base year often passed through) | Usually landlord; sometimes increases passed through | Tenant's pro-rata share |
| CAM / common areas | Landlord | Usually landlord | Tenant's pro-rata share |
| Utilities & janitorial (suite) | Landlord, business hours | Tenant | Tenant |
| Cost predictability | High | Medium | Low (reconciled annually) |
| Typical for | Multi-tenant office | Small office, flex, mixed-use, medical | Retail, industrial, single-tenant |
For the other two structures in depth, see full-service gross leases and NNN vs. gross leases.
Why landlords offer modified gross
Modified gross is common in smaller multi-tenant office buildings, flex and light-industrial parks, mixed-use buildings, and medical office, where suites are separately metered and the landlord wants to keep control of the building systems while shedding the tenant-specific costs that vary the most (power-hungry equipment, after-hours use, cleaning standards). For the landlord it removes the utility risk of a full-service lease; for the tenant it avoids the open-ended reconciliations of NNN. Both sides get a rent number that is mostly predictable.
Negotiating a modified gross lease
- Get the expense list in writing. Ask for an exhibit that names every cost the tenant pays and every cost the landlord pays. “Tenant pays utilities” should specify which ones and how they are metered or allocated.
- If there is a base year, pick it carefully. A base year set during high vacancy or unusually low expenses means bigger pass-throughs later; ask for a gross-up clause that adjusts variable expenses to a stabilized occupancy (commonly 95%).
- Cap the controllable expenses — management fees, landscaping, security — at a fixed annual increase, and exclude capital items and the landlord's corporate overhead.
- Ask for audit rights on any pass-through reconciliation, and a deadline by which the landlord must deliver it.
- Model the whole term with escalations (fixed 3% or CPI-linked are both common) and any pass-through growth, not just year one.
California notes
Commercial leases in California are governed by the lease itself, not by residential tenant law. Since January 1, 2025 (SB 1103), qualified commercial tenants — microenterprises with five or fewer employees, restaurants with fewer than ten, and nonprofits with fewer than twenty, who give the landlord written notice of that status — are entitled to a proportionate allocation and documentation of any building operating costs passed through, and can request the supporting records. Separately, every commercial lease must state whether the premises have been inspected by a Certified Access Specialist (CASp) and provide the report if one exists (Civil Code §1938). For any lease longer than a year, have a commercial-experienced attorney read the expense clause; it is where most of the money in a modified gross lease lives.