How can I get my year 2015 W2s and 1099s if I'll be moving by mid January 2016?

Let your employer know your new address NOW. If you won't have an address before 12/31...

then ask your employer to hold your W-2's and 1099's and you will pick them up.

The USPS will NOT forward W-2's or 1099's.

Contact your issuers of your change of address before you move. Complete a change of address form with the post office.

Figure out which forms are available online. Many W-2's and 1099's are available from employers, pensions, banks, etc.

If you file a proper change of address with the post office ALL your mail will be forwarded including all yoru 1099 and W-2s, what you heard is 100% wrong

Unless you work for the federal government your W-2 is not sent by the feds, it is sent by your employer. So you should keep your (former?) employer advised of your current address, especially if you still have a 401k there that you have not transferred to another trustee. But if you have your mail forwarded, until that expires (6 months I think) your W-2 should still get to your new address.

Update: Not all mail gets forwarded. Anything NOT first class will not get forwarded. Also certain government letters and documents do not get forwarded. A friend of mine filed a change of address, but Social Securty sent him an latter which he did not respond to and did not get due to a policy a non-forwarding SS letters, and his benefits f=were terminated, for real.

Common sense says to put in a forwarding order and give your employer your change of address.

They will be forwarded as long as you file a change of address with the post office.

Do an official change of address with the post office, they will be forwarded

Also notify the sender of your new address

you let the people know where you want it mailed if the current address they have will not be valid

or better yet

provide them a self addressed stamped envelope to the address youchoose(whether it is where you will be or an address you can receive mail

Just file paperwork with your current USPS. If you're in doubt, ask the counter person when you turn in the paperwork.