By invoking a standard variable transformation x → y ≡ x 2 that connects the eigenvalue problems of the hydrogen atom system (Coulomb potential) and the Kratzer oscillator system, we obtain a system of ladder operators ± nl (l = 0, 1, 2, . . . , n − 1) that connect the degenerate energy eigenstates (belonging to different l-values) of the hydrogen atom system. Using such quantum number specific operators as the precursors, we develop a general method of constructing quantum number independent ladder operators P± ; and then investigate the general conditions for these operators to form a realization of the su(2) algebra. In the process, we demonstrate that, in general, a finite-dimensional linear vector space carries a realization of the su(2) algebra. Applying the method to the case at hand, we show that for the hydrogen atom system the operators P± and P0 ≡ 1 2 [ P+ , P− ] form an su(2) algebra. The Hamiltonian is identified with the Casimir operator of the algebra, thereby revealing a dynamical SU(2) group symmetry of the hydrogen atom system.