An employer-established retirement savings plan to which employees contribute a portion of their salary. Some employers may match employee contributions, and some may add a profit-sharing option to the plan. In a Traditional 401k, contributions are taxed upon withdrawal, while in a Roth 401k contributions are post-tax.

Can be issued by a 501(c)(3) organization to finance activities related to the exempt purposes of the organization. Provides nonprofits with the option of developing residential rental housing without the strict set-aside restrictions of exempt-facility bonds.

Nonprofit with tax-exempt fiscal status. Criteria include organized and operated exclusively for religious, charitable, scientific, public safety or educational purposes, no substantial part of the activities of which is carrying on propaganda or otherwise trying to influence legislation or political elections, nor from which any private shareholder or individual inures benefit. Can offer tax deductions for contributions.

Civic league organization created, for example, for the promotion of social welfare or organization of employees. Net earnings are devoted exclusively to charitable, educational or recreational purposes. No tax deductions offered for contributions. No prohibition of political activity.

Activities are not charitable, contributions are not tax deductible, and there is no prohibition for political activity. Examples include chambers of commerce, business leagues and real estate boards.