A full service lease, sometimes known as a full service gross lease, or FSG lease, is a type of commercial real estate lease in which the landlord is responsible for paying all operating expenses for the property. This typically includes insurance, utilities, necessary property repairs and maintenance, taxes, and other, unexpected expenses, but can vary greatly from lease to lease.

A modified gross lease, or MG lease, is a type of commercial real estate lease where the property owner and the tenant share in the operational costs of the property, including utilities, insurance, taxes, and maintenance. An MG lease can be considered to be a hybrid between a NNN (triple net) lease and an FSG (full-service gross) lease.