| 00-XX | General |
| 01-XX | History and biography [See also the classification number -03 in the other sections] |
| 03-XX | Mathematical logic and foundations |
| 05-XX | Combinatorics {For finite fields, see 11Txx} |
| 06-XX | Order, lattices, ordered algebraic structures [See also 18B35] |
| 08-XX | General algebraic systems |
| 11-XX | Number theory |
| 12-XX | Field theory and polynomials |
| 13-XX | Commutative rings and algebras |
| 14-XX | Algebraic geometry |
| 15-XX | Linear and multilinear algebra; matrix theory |
| 16-XX | Associative rings and algebras {For the commutative case, see 13-XX} |
| 17-XX | Nonassociative rings and algebras |
| 18-XX | Category theory; homological algebra {For commutative rings see 13Dxx, for associative rings 16Exx, for groups 20Jxx, for topological groups and related structures 57Txx; see also 55Nxx and 55Uxx for algebraic topology} |
| 19-XX | K-theory [See also 16E20, 18F25] |
| 20-XX | Group theory and generalizations |
| 22-XX | Topological groups, Lie groups {For transformation groups, see 54H15, 57Sxx, 58-XX. For abstract harmonic analysis, see 43-XX} |
| 26-XX | Real functions [See also 54C30] |
| 28-XX | Measure and integration {For analysis on manifolds, see 58-XX} |
| 30-XX | Functions of a complex variable {For analysis on manifolds, see 58-XX} |
| 31-XX | Potential theory {For probabilistic potential theory, see 60J45} |
| 32-XX | Several complex variables and analytic spaces {For infinite- dimensional holomorphy, see 46G20, 58B12} |
| 33-XX | Special functions (33-XX deals with the properties of functions as functions) {For orthogonal functions, see 42Cxx; for aspects of combinatorics, see 05Axx; for number-theoretic aspects, see 11-XX; for representation theory, see 22Exx} |
| 34-XX | Ordinary differential equations |
| 35-XX | Partial differential equations |
| 37-XX | Dynamical systems and ergodic theory [See also 26A18, 34Cxx, 34Dxx, 35Bxx, 46Lxx, 58Jxx, 70-XX] |
| 39-XX | Difference and functional equations |
| 40-XX | Sequences, series, summability |
| 41-XX | Approximations and expansions {For all approximation theory in the complex domain, see 30Exx, 30E05and 30E10; for all trigonometric approximation and interpolation, see 42Axx, 42A10and 42A15; for numerical approximation, see 65Dxx} |
| 42-XX | Fourier analysis |
| 43-XX | Abstract harmonic analysis {For other analysis on topological and Lie groups, see 22Exx} |
| 44-XX | Integral transforms, operational calculus {For fractional derivatives and integrals, see 26A33. For Fourier transforms, see 42A38, 42B10. For integral transforms in distribution spaces, see 46F12. For numerical methods, see 65R10} |
| 45-XX | Integral equations |
| 46-XX | Functional analysis {For manifolds modeled on topological linear spaces, see 57N20, 58Bxx} |
| 47-XX | Operator theory |
| 49-XX | Calculus of variations and optimal control; optimization [See also 34H05, 34K35, 65Kxx, 90Cxx, 93-XX] |
| 51-XX | Geometry {For algebraic geometry, see 14-XX} |
| 52-XX | Convex and discrete geometry |
| 53-XX | Differential geometry {For differential topology, see 57Rxx. For foundational questions of differentiable manifolds, see 58Axx} |
| 54-XX | General topology {For the topology of manifolds of all dimensions, see 57Nxx} |
| 55-XX | Algebraic topology |
| 57-XX | Manifolds and cell complexes {For complex manifolds, see 32Qxx} |
| 58-XX | Global analysis, analysis on manifolds [See also 32Cxx, 32Fxx, 32Wxx, 46-XX, 47Hxx, 53Cxx] {For geometric integration theory, see 49Q15} |
| 60-XX | Probability theory and stochastic processes {For additional applications, see 11Kxx, 62-XX, 90-XX, 91-XX,92-XX, 93-XX, 94-XX] |
| 62-XX | Statistics |
| 65-XX | Numerical analysis |
| 68-XX | Computer science {For papers involving machine computations and programs in a specific mathematical area, see Section -04 in that area} |
| 70-XX | Mechanics of particles and systems {For relativistic mechanics, see 83A05 and 83C10; for statistical mechanics, see 82-XX} |
| 74-XX | Mechanics of deformable solids |
| 76-XX | Fluid mechanics {For general continuum mechanics, see 74Axx, or other parts of 74-XX} |
| 78-XX | Optics, electromagnetic theory {For quantum optics, see 81V80} |
| 80-XX | Classical thermodynamics, heat transfer {For thermodynamics of solids, see 74A15} |
| 81-XX | Quantum theory |
| 82-XX | Statistical mechanics, structure of matter |
| 83-XX | Relativity and gravitational theory |
| 85-XX | Astronomy and astrophysics {For celestial mechanics, see 70F15} |
| 86-XX | Geophysics [See also 76U05, 76V05] |
| 90-XX | Operations research, mathematical programming |
| 91-XX | Game theory, economics, social and behavioral sciences |
| 92-XX | Biology and other natural sciences |
| 93-XX | Systems theory; control {For optimal control, see 49-XX} |
| 94-XX | Information and communication, circuits |
| 97-XX | Mathematics education |