Does a 401(k) rollover into an IRA use up my annual IRA contribution limit?

No. Rollovers and contributions are completely separate in the eyes of the IRS. Moving money from a 401(k) into a Traditional or Roth IRA via a direct rollover doesn't count against your annual contribution cap, no matter how large the balance. You could roll over hundreds of thousands and still make your full new contribution for the year. What is limited is the once-per-12-months rule on indirect (60-day) IRA-to-IRA rollovers, which doesn't apply to direct trustee-to-trustee transfers or to 401(k)-to-IRA rollovers. Always prefer a direct rollover to avoid mandatory withholding and the 60-day redeposit trap. Confirm the current rollover rules at irs.gov.