Congress’ or Congress’s?

The term congress’s is the standard singular possessive form of congress. E.g., “Congress’s members are returning to session today.” Furthermore, the version congress’ is the older version, which is still common. E.g., “Congress’ session starts tomorrow.”

The following table shows the different forms of the term congress.

Singular possessiveCongress’s / Congress’
Plural possessiveCongresses’

As you can see, because congress ends in double “s,” we form the plural by adding “-es.”

The advice regarding the possessive varies depending on who you ask. However, in modern English, most guidance leans towards using congress’s as the singular possessive form.

If you follow the Bluebook, you should use congress’s on most occasions.

Here are some examples of the different forms of the word congress in context:

  • Singular: The senator addressed Congress and announced his bid for the presidency.
  • Plural: Congresses worldwide have been discussing the topic of climate change.
  • Singular possessive: Congress’s constitutional powers are what govern the country.
  • Plural possessive: The congresses’ objectives were fulfilled by the treaty.

Now that you have seen the different forms of congress in context, please keep reading to learn more about the meaning of congress and how you can use the various forms.

We’ll explain in more detail what the AP Stylebook and the Bluebook have to say about the singular possessive form of congress.


The word congress’ is an acceptable singular possessive form of congress.

Furthermore, it is the original possessive form and was only overtaken in popularity in American English in the early 2000s.

  • The Supreme Court denied Congress’ proposal by a majority of 4-3.

Also, some official bodies, such as the Supreme Court, still use the version Congress’ when referring to something possessed by the US Congress.

The word congress is a little more complicated than other words because it can be a proper and common noun.

As a proper noun, it refers to a specific congress, such as the US Congress. However, as a common noun, it refers to meetings or conferences.

This difference complicates things because style guides such as the AP Stylebook have different specifications for common and proper nouns. Consequently, for proper nouns, you should use Congress’, and for common nouns, you should use congress’s.

These examples show how the two meanings of congress look in AP Style:

  • Congress’ vote produced a shock result.
  • The environmental congress’s objective was to reach an agreement on fossil fuels.

Furthermore, people often use congress’ instead of congress’s when the following word begins with “s.” However, if you use this version once in a document, you should make sure you do it throughout the text.


The term congress’s is also an acceptable singular possessive form of congress.

In previous decades the possessive version congress’ was more common. However, in modern English, the trend is always to add the “s” after the apostrophe. Therefore, in American English, congress’s has become more popular than its predecessor congress’.

Also, the Bluebook that governs how US Government and legal documents should be written states that you should use congress’s unless the following word is difficult to pronounce with an “s” before it.

  • Congress’s policy on student loan deferral saved many people thousands of dollars.
  • Congress’ seating plan has not changed in over a century.

If the following word sounds awkward, then you can drop the final “s.” However, if you choose to do this, you should be consistent and do it throughout the text.

Moreover, in AP Style, the word congress can be a little tricky because it is a common and proper noun. Therefore, when referring to a specific congress, such as the US Congress, you should use Congress’.

  • The US Congress’ spokesperson has resigned with immediate effect.

However, if you refer to a congress, as in a meeting or conference, then you should use congress’s.

  • The congress’s objective remained unfulfilled after three days of negotiations.


The term congresses is the plural version of the word congress. Therefore, you use it to mention more than one congress. The word congress has two primary meanings.

The first is to refer to a government authority made up of senators or members. In this context, it is not that common to refer to multiple congresses because they are proper nouns, and you usually refer to their actions in a singular context.

  • Congresses in the region have gathered to discuss the oil crisis.

The second meaning of congress is similar to that of a conference or meeting. In this context, it is more common to use the plural form.

  • The congresses the government held with its allies helped with strategic war planning.

Finally, when you use the plural form of congress, you need to make sure that the thing you refer to is not owned or possessed by the congresses. If it is, you should use the plural possessive.

  • The congresses’ minutes will be available on our website from next week.