There are many types of nonprofits that are registered by the IRS, and they all have different designations. For instance, a child care nonprofit is a 501(k) and a Chamber of Commerce is a 501(c)(6). Here is a list of the types of nonprofits that the IRS recognizes. This information comes from IRS Publication 557:

501(c)(1)

These are corporations organized under Act of Congress. Federal Credit Unions are a good example of this type of nonprofit. These nonprofits do not have to file an annual return. Tax-exempt contributions are allowed if they are made for exclusively public purposes.

501(c)(2)

These are holding corporations for exempt organizations. That is, they can hold title to property of an exempt group. They apply for nonprofit status using IRS form 1024. They annually file forms 990 or 990EZ.

501(c)(3)

This is the most common type of nonprofit. It includes organizations that are religious, educational, charitable, scientific, and literary; groups that test for public safety, that foster national or international amateur sports competition; or organizations engaged in the prevention of cruelty to children or animals.

This type of nonprofit applies for its status using IRS form 1023 and files annually form 990, 990EZ, or 990-PF. Contributions are usually tax-exempt.

All 501(c)(3) organizations are considered either:

A private foundation. These are nonprofits that don’t qualify as public charities. Foundations may be sub-classified as private operating foundations or private non-operating foundations, and receive some of the advantages of public charities.

Or a public charity.

501(c)(4)

These are civic leagues, social welfare organizations, and local associations of employees. They promote community welfare, charitable, education or recreational goals. They apply using IRS Form 1024. They file annually 990 or 990EZ.

501(c)(5)

Labor, agricultural, and horticultural organizations fit under this classification. They are educational or instructive, with the goal of improving conditions of work, and to improve products and efficiency. They apply by using IRS Form 1024, and file annually form 990 or 990EZ.

501(c)(6)

These organizations are business leagues, chambers of commerce, real estate boards, etc. They seek to improve business conditions. They apply using IRS form 1024 and file annually the 990 or 990EZ.

501(c)(7)

Social and recreation clubs fall into this category. They promote pleasure, recreation, and social activities. They apply using IRS form 1024 and file annually the 990 or 990EZ.

501(c)(8)

This category includes fraternal beneficiary societies and associations. They provide for the payment of life, sickness, accident, or other benefits to members. They apply using IRS form 1024 and file annually the 990 or 990EZ.