At the beginning of a sentence, we do not need to place a comma after short adverbial phrases, like “in the interim”. Longer introductory phrases (more than four words), such as “in the course of...”, are commonly followed by a comma.

At the beginning of a sentence, we do not need to place a comma after short adverbial phrases, like “in the interim”.

In the interim you must protect yourself.

Longer introductory phrases (more than four words), such as “in the course of...”, are commonly followed by a comma.

In the course of the last few months, you’ve done a fantastic job.

When using these expressions in the middle or at the end of a sentence, commas are usually unnecessary—although they may be required in particular situations.

This is precisely what has been happening in the course of the last few years.

1. Commas At the Beginning of a Sentence

We do not frequently add a comma after brief introductory phrases, like “in the interim”.

In the interim I'd like to ask you a few questions.

But you can optionally use a comma to signal a pause.

In the interim, we'll take all the necessary measures to stop this dangerous trend.

If the introductory phrase contains more than three or four words, such as “in the course of ...”, we typically add a comma after it.

In the course of the investigation, two suspects have been arrested at the Mexican border.

You can optionally drop the comma, however, if the sentence is clear—even if the prepositional phrase has more than five words.

In the course of time you’ll forget her.

But use commas to avoid confusion or make complicated sentences clearer.

In the course of the last several months, consumer prices have accelerated at its fastest pace since 1982.

Follow the same comma strategy when using the expression "for the time being".

2. Commas In the Middle or At the End of a Sentence

Commas are often unnecessary when using the expressions “in the course of” or “in the interim” in mid-sentence.

The step forward we have taken in the course of the last few years is a success shared by all of us in this conference room.

Olivia is planning to buy a new house next year, but in the interim she is sharing a flat with two friends.

However, you may need to use a comma before and after these expressions to signal a pause, create a parenthetical feel, add a series of coordinate phrases, connect a coordinating conjunction to introduce an independent clause, etc.

But, in the interim, we have a duty to maintain law and order.

Along this journey, in the course of the last ten years, this community has become my family.

Follow the same policy to determine whether to use commas with the expression "in the meantime"