A participant who is absent from a position of employment subject to the Cash Balance Benefit Program due to that participant’s service in the uniformed services, shall not be entitled to obtain the right to contribute toward credits under the plan in excess of five years of service in the uniformed services, except for the following reasons: (

a) The participant is required to serve beyond five years to complete an initial period of obligated service in the uniformed services; (

b) The participant was unable to obtain orders releasing the participant from a period of service in the uniformed services before the expiration of the five-year period and that inability was through no fault of the participant; (

c) The participant served in the uniformed services as required pursuant to

Section of Title 10, under

Section 502(

a) or of Title of the United States Code, or to fulfill additional training requirements determined and certified in writing by the Secretary of Defense, to be necessary for professional development, or for completion of skill training or retraining; or (

d) The participant is:

(1) Ordered to or retained on active duty under

Section 672(a), 672(g), 673, 673b, 673c, or of Title or under

Section 331, 332, 359, 360, 367, or of Title of the United States Code.

(2) Ordered to or retained on active duty, other than for training, under any provision of law during a war or during a national emergency declared by the President or the Congress.

(3) Ordered to active duty, other than for training, in support, as determined by the secretary concerned, of an operational mission for which personnel have been ordered to active duty under

Section 673b of Title of the United States Code.

(4) Ordered to active duty in support, as determined by the secretary concerned, of a critical mission or requirement of the uniformed services.

(5) Called into federal service as a participant of the National Guard under

Chapter of Title or under

Section or of Title of the United States Code.