England have announced that Test captain Root and wicketkeeper Bairstow can play in the fixtures at Chelmsford (May 4-7) and at The Oval (May 11-14).
They are the only county matches for which they are available ahead of the first Test against Pakistan at Lord’s on May 24.
England have also confirmed that Gary Ballance, David Willey and Liam Plunkett are available for all of Yorkshire’s early-season matches.
Full England player availability for the early stages of the Specsavers County Championship:
Alastair Cook (Essex) – available for Championship matches against Hampshire (April 27-30), Yorkshire (May 4-7) and Worcestershire (May 11-14).
James Vince (Hants) – available for all games from April 13 (but not v Oxford MCCU April 7-9).
Liam Livingstone (Lancs) – available for all games from April 13 (but not v Loughborough MCCU April 7-9).
Jimmy Anderson (Lancs) – tbc.
Dawid Malan (Middlesex) – available for Championship matches against Glamorgan (27-30 April), Sussex (4-7 May), and Gloucestershire (11-14 May).
Eoin Morgan (Middlesex) – available for all matches.
Stuart Broad (Notts) – available for Championship matches against Worcestershire (27-30 April), Hampshire (4-7 May) and Lancashire (11-14 May).
Mark Stoneman and Ben Foakes (Surrey) – available for all games from April 20 (but not v Cambridge MCCU April 13-15).
Joe Root and Jonny Bairstow (Yorks) – available for Championship matches against Essex (4-7 May) and Surrey (11-14 May).
Liam Plunkett, Gary Ballance, and David Willey (Yorks) – available for all matches.
Moeen Ali (Worcestershire), Jos Buttler (Lancashire), Jason Roy (Surrey), Ben Stokes (Durham),Chris Woakes (Warwickshire) and Mark Wood (Durham) are all unavailable for the start of the season, having signed to play in the Indian Premier League.
Players selected for the first Test of the summer against Pakistan which starts at Lord’s on May 24 have been told by the ECB that they are expected to return by May 17, with availability for Royal London One-Day Cup fixtures to be confirmed nearer the time.