as mention (mentioned)

"As mentioned" signals a reference to something stated earlier. Small slips-missing subject, missing comma, or an unclear referent-make writing look sloppy or force readers to hunt for meaning.

Below: concise rules, clear punctuation tips, and plenty of wrong/right pairs and rewrites you can copy for work, school, and casual messages.

Quick answer

Use "as mentioned" only when the referenced idea is obvious. Prefer an explicit subject (As I mentioned, As we mentioned, As Dr. Lee mentioned), add a comma when it starts a clause (As mentioned earlier, ...), and if the original mention is distant, repeat the noun or rewrite (Earlier, I explained that...).

Add a subject when the speaker or source matters: "As I mentioned, ..."
If the phrase opens a clause, follow it with a comma: "As mentioned above, ..."
If the original mention is far away, repeat the noun or rewrite: "As I mentioned in Section 2, the budget..."

Core explanation: what "as mentioned" does and why it breaks

"As mentioned" is an introductory adverbial that points back to an earlier statement. For it to work, you need a clear referent, correct punctuation, and either proximity to the original mention or enough repeated context to reconnect the reader.

When those elements are missing you get vagueness (Who mentioned it?), punctuation errors (missing comma), or cognitive friction (reader has to hunt).

Referent: Who or what was mentioned? Add a subject or repeat the noun if unclear.
Punctuation: If the phrase begins a clause, use a comma; if it interrupts, set it off with commas.
Distance: If the original idea is several sentences back, repeat the noun or rewrite.

Punctuation and spacing: exact fixes

Rule 1: If the phrase begins the clause, put a comma after it: "As mentioned earlier, the plan changes."

Rule 2: If it appears mid-sentence as a parenthetical, use commas on both sides: "The plan, as mentioned earlier, changes on Monday."

Rule 3: Always ensure a space after a comma; missing spaces are distracting typos.

Introductory: "As mentioned above, please review the draft."
Parenthetical: "The draft, as mentioned above, needs citations."
Spacing: "As mentioned, please" not "As mentioned,please"

Wrong: As mentioned the schedule will change next week.
Right: As mentioned earlier, the schedule will change next week.
Wrong: As mentioned,please send the updated file.
Right: As mentioned, please send the updated file.
Wrong: We will as mentioned earlier start tests next week.
Right: We will, as mentioned earlier, start tests next week.

Hyphenation and compound forms

Do not hyphenate "as mentioned." It's a clause, not a compound adjective. If you need an adjective before a noun, use "previously mentioned" or "mentioned earlier."

Wrong: "as-mentioned" - avoid it.
Better: "previously mentioned items" or "items mentioned earlier."

Wrong: Please review the as-mentioned items.
Right: Please review the previously mentioned items.

Grammar pitfalls: missing subject and dangling reference

A bare "As mentioned" can be grammatical but vague. In business and academic settings, name the subject or source: "As I mentioned," "As we mentioned," or "As Dr. Park mentioned."

If the referenced idea is several sentences back, repeat the noun to reconnect: instead of "As mentioned earlier, it failed," write "As mentioned earlier, the experiment failed."

Add a subject if the speaker matters: "As I mentioned" or name the person.
Repeat the key noun if the referent isn't immediate: "As I mentioned earlier, the budget spreadsheet..."
If the original is in another document, cite it: "As I mentioned in my last email" or "see Section 2."

Wrong: As mentioned, the policy must be updated after review.
Right: As I mentioned, the policy must be updated after review.
Wrong: As mentioned earlier the sample was excluded.
Right: As mentioned earlier, the sample was excluded.

Real usage and tone: work, school, casual

Adjust phrasing to the audience. Business writing benefits from ownership or a citation; academic writing prefers "as noted" or explicit citations; casual messages can use short first-person forms when the referent is fresh.

Business: "As I mentioned in my previous email," or "Per my earlier message,"
Academic: "As noted above," or a section citation
Casual: "As I mentioned," with a comma when the referent is recent

Work - Wrong: As mentioned the Q3 numbers are attached.
Work - Right: As I mentioned, the Q3 numbers are attached.
Work - Wrong: As mentioned I need approval by Friday.
Work - Right: As I mentioned in my last email, I need approval by Friday.
Work - Wrong: As mentioned, please send the contract
Work - Right: As mentioned earlier, please send the contract.
School - Wrong: As mentioned the hypothesis failed.
School - Right: As discussed earlier in class, the hypothesis failed.
School - Wrong: As mentioned above the sample size was small.
School - Right: As noted above, the sample size was small.
School - Wrong: As mentioned the reading is required.
School - Right: As I mentioned in class, the reading is required.
Casual - Wrong: As mentioned I'll pick you up at 6.
Casual - Right: As I mentioned, I'll pick you up at 6.
Casual - Wrong: As mentioned don't wait for me.
Casual - Right: As I mentioned, don't wait for me.
Casual - Wrong: As mentioned I'll bring dessert
Casual - Right: As I mentioned, I'll bring dessert.

Try your own sentence

To test whether "as mentioned" works, read the whole sentence aloud and ask whether the referent is obvious. If not, add a subject, a comma, or replace the phrase. If helpful, paste the sentence into the widget below.

Examples: wrong/right pairs and ready rewrites

Scan the pairs and copy the "Right" sentences that match your tone. After the pairs are six quick rewrites that remove "as mentioned" entirely when that cleaner fix is best.

Wrong: As mentioned the meeting is at 3.
Right: As I mentioned earlier, the meeting is at 3 p.m.
Wrong: As mentioned above the files are outdated.
Right: As mentioned above, the files are outdated.
Wrong: As mentioned please update your timesheet.
Right: As I mentioned, please update your timesheet.
Wrong: As mentioned in class the reading is required.
Right: As I mentioned in class, the reading is required.
Wrong: As mentioned I'll pick you up at 6.
Right: As I mentioned, I'll pick you up at 6.
Wrong: As mentioned earlier the budget needs revision.
Right: As mentioned earlier, the budget needs revision.
Rewrite - Formal: As I mentioned in my previous email, please find the attached report.
Rewrite - Neutral: Earlier, I noted that the budget needs revision.
Rewrite - Concise: The budget needs revision, as previously noted.
Rewrite - Academic: As noted above (see Section 2), the sample size is small.
Rewrite - Casual: Like I said, I'll bring snacks.
Rewrite - When distant: In my prior message, I explained that the deadline would move.

Fix your sentence: checklist + three live rewrites

Checklist: (1) Who mentioned it? Add a subject if needed. (2) Is the phrase at the start or parenthetical? Add comma(s). (3) Is the original mention far away? Repeat a noun or cite the location. (4) Match the tone (formal, neutral, casual).

One wrong sentence, three fixes by tone:

Wrong: As mentioned the final draft needs more examples.
Formal fix: As I mentioned in my previous message, the final draft needs more examples.
Neutral fix: As mentioned earlier, the final draft needs more examples.
Concise fix: The final draft needs more examples, as previously noted.

Memory trick: S or C? (Subject or Comma)

Ask "S or C?" - does the phrase need a Subject (S) or a Comma (C)? If neither, rewrite. This quick check prevents most errors.

If answer = S: add "I/we/Dr. X."
If answer = C: add a comma after the phrase or commas on both sides if it's parenthetical.
If the referent is remote, repeat a key noun instead of only adding a subject.

Similar mistakes and alternatives

Alternatives include "as noted," "as discussed earlier," "as previously mentioned," and "aforementioned." Choose based on clarity and tone.

Use "as noted" for a neutral formal tone, "as discussed earlier" for papers and reports, and avoid "aforementioned" unless you need a very formal register.

Wrong: Aforementioned issues must be fixed before launch.
Right: The issues mentioned above must be fixed before launch.
Wrong: As noted earlier the sample size was small.
Right: As noted earlier, the sample size was small.

FAQ

Is it correct to say "As mentioned" without a subject?

Yes, but it's often vague. Use a bare "As mentioned" only when the referent is immediately obvious (same or directly preceding sentence). In emails or formal writing, add a subject or repeat the noun for clarity.

Do I always need a comma after "as mentioned earlier"?

When the phrase starts a sentence or clause, yes-treat it as introductory and follow it with a comma. If it appears as a parenthetical mid-sentence, use commas on both sides.

Should I use "as mentioned above" in academic writing?

Prefer "as noted above" or an explicit citation (for example, "see Section 2"). Avoid first-person phrasing in formal papers unless your discipline allows it.

How do I rewrite a sentence that awkwardly starts with "As mentioned"?

Options: add a subject (As I mentioned, ...), move the phrase later (The plan, as mentioned earlier, ...), or replace it with an explicit alternative (Earlier, I explained that...). Choose based on tone and how far back the original mention is.

Is "as-mentioned" an acceptable hyphenation?

No. Don't hyphenate "as mentioned." Use "previously mentioned" or "mentioned earlier" when you need an adjective before a noun.

Want a quick check on one sentence?

If you're unsure, paste your sentence into a grammar checker or try one of the rewrites above: add a subject (As I mentioned), add a comma, or replace the phrase with a clearer alternative. Small edits often remove the confusion and make your message read professionally.