I am a US citizen and would like to transfer money from a foreign account into a US-based account. The money in question is my savings, in the amount of approximately $50,000.

It seems the easiest way to transfer the funds is via a wire transfer, but I've read posts that indicate the money may be subject to US tax?

Is there paperwork I could file to make sure the money is not taxed as income?

Thank you in advance for your advice.

It should NOT be subject to U.S. taxes if you can show from where the money came.

You WILL have to submit paper work to properly account for the money, but, assuming that all required taxes have already been paid when this money was earned, no additional taxes will be due.