I worked at a hospital for a year before moving and switching to a difference one. I forgot I had mail from a company called Retirement ClearingHouse that is holding my previous employer's 401k balance. I really don't know much knowledge with these things since I am still trying to educate myself. I want to transfer the money from this company to my current 401k retirement account. Is that possible? I use fidelity to manage and track my 401k with my current employer.

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There is an option to either close the account or withdraw. What is the best way to get it into m current retirement account without getting taxed or penalized with fees? Sorry if this doesn't make too much sense!