S.D. Codified Laws § 3-12C-812
A contributing member who becomes disabled and who has acquired at least three years of contributory service or noncontributory service since the member's most recent entry into active status and before becoming disabled, or was disabled by accidental means while performing usual duties for an employer, is eligible for disability benefits if the disability is expected to be of long, continued, and indefinite duration of at least one year and the member is disabled on the date the member's contributory service ends. For purposes of this section, a transfer within a participating unit, or a change in employment from one participating unit to another participating unit if there is no break in contributory service, does not constitute a new entry into active status.
SDCL 3-12C-812