Your work as an employee, but only if the use of the home office is for the convenience of your employer (think: hygiene issues).

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Of course, these comparisons also ignore the convenience factor as well as the value of your time.

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As for convenience, some plan administrators, such as Fidelity Investments, are able to distribute your contributions from each paycheck to out-of-plan mutual funds, the way they would to in-plan funds.

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