The San Antonio Spurs hold the longest active consecutive playoff appearances with 21 appearances, starting in the 1998 NBA Playoffs (also the longest active playoff streak in any major North American sports league as of 2017). The Spurs have won five NBA championships during the streak. The Philadelphia 76ers (formerly known as Syracuse Nationals) hold the all-time record for consecutive playoff appearances with 22 straight appearances between 1950 and 1971. The 76ers won two NBA championships during their streak. The Boston Celtics hold the longest consecutive NBA Finals appearance streak with ten appearances between 1957 and 1966. During the streak, the Celtics won eight consecutive NBA championships--also an NBA record.

has anyone ever won 4 nba championships in a row?
yes