The published 1981 score claims "1949-50", but apparently the work was completed November 2 1949, including orchestration.

Symphonies by Nikolay Myaskovsky
Symphony No.1 in C minor, Op.3 (1908, rev.1921) Symphony No.2 in C♯ minor, Op.11 (1910-11) Symphony No.3 in A minor, Op.15 (1914) Symphony No.4 in E minor, Op.17 (1917-18) Symphony No.5 in D major, Op.18 (1917-18) Symphony No.6 in E♭ minor, Op.23 (1921-23) Symphony No.7 in B minor, Op.24 (1922) Symphony No.8 in A major, Op.26 (1924-25) Symphony No.9 in E minor, Op.28 (1926-27) Symphony No.10 in F minor, Op.30 (1926-27) Symphony No.11 in B♭ minor, Op.34 (1931) Symphony No.12 in G minor "October", Op.35 (1931-32) Symphony No.13 in B♭ minor, Op.36 (1933) Symphony No.14 in C major, Op.37 (1933)	Symphony No.15 in D minor, Op.38 (1933-34) Symphony No.16 in F major, Op.39 (1935-36) Symphony No.17 in G♯ minor, Op.51 (1936-37) Symphony No.18 in C major, Op.42 (1937) Symphony No.19 in E♭ major, Op.46 (1939) Symphony No.20 in E major, Op.50 (1940) Symphony No.21 in F♯ minor, Op.51 (1940) Symphony No.22 in B minor "Ballade", Op.54 (1941) Symphony No.23 in A minor, Op.56 (1941) Symphony No.24 in F minor, Op.63 (1943) Symphony No.25 in D♭ major, Op.69 (1945-46, rev.1949) Symphony No.26 in C major "On Russian Themes", Op.79 (1948) Symphony No.27 in C minor, Op.85 (1949)

Symphonies by Nikolay Myaskovsky