US equity futures were mixed pre-bell Tuesday as traders digested key earnings ahead of the start of the Federal Reserve's two-day policy meeting.

Dow Jones Industrial Average futures were 0.5% lower, while S&P 500 futures were up 0.2%, and Nasdaq futures were 0.6% higher.

The Federal Open Market Committee begins its meeting Tuesday and will issue a policy statement at 2 pm ET on Wednesday.

On the earnings front, UnitedHealth Group (UNH) reported lower Q4 adjusted earnings amid higher revenue. RTX (RTX) reported higher Q4 adjusted earnings and sales, and Boeing (BA) reported it swung to Q4 core earnings amid higher revenue.

Oil prices were higher, with front-month global benchmark North Sea Brent crude up 0.1% at $64.82 per barrel and US West Texas Intermediate crude 0.2% higher at $60.73 per barrel.

The November S&P Case-Shiller Home Price Index is scheduled for release at 9 am ET.

The January Consumer Confidence index, due at 10 am ET, is expected at 90.6 versus 89.1 previously, according to estimates compiled by Bloomberg.