However, if an employee or Member retiring under section
8337 of this title is receiving retired pay or retainer pay for military service (except that specified in section
8332
(c)(1) or (2) of this title) or pension or compensation from the Department of Veterans Affairs in lieu of such retired or retainer pay, the annuity of that employee or Member shall be computed under subsection (a), (b), (c), (n), (q), (r), or (s), as appropriate, excluding credit for military service from that computation. If the amount of the annuity so computed, plus the retired or retainer pay which is received, or which would be received but for the pension or compensation from the Department of Veterans Affairs in lieu of such retired or retainer pay, is less than the smaller of the annuity otherwise payable under paragraph (1) or (2) of this subsection, an amount equal to the difference shall be added to the annuity payable under subsection (a), (b), (c), (n), (q), (r), or (s), as appropriate.