I accidentally deposited post tax contributions from my 401k into my regular brokerage account. Can I simply transfer them into my Roth IRA as I intended?

[rmcfarlin001]

Both the accidental and the correction transactions would be occurring in the same tax year.

[dmertz]

Yes, if done within 60 days of receiving the distribution.  This will be in indirect rollover.

[fanfare]

"simply transfer"

It's not so simple; you have 60 days to correct your mistake.

@rmcfarlin001 

[Opus 17]

An IRA is not a 401k, even though they have a similar purpose.  I think you meant, you were doing a rollover from a Roth designated 401k to a Roth IRA.  If you withdrew money from your 401k, you have 60 days to deposit that money into an IRA, for it to count as a rollover.  You can only do one indirect rollover per year.  

[dmertz]

@Opus 17 , this appears to involve the after-tax portion of a distribution from the traditional 401(k) account, nothing from a designated Roth account.

Also, there is no limitation on rollovers from a 401(k).