Unless exempt from the basic training requirements as defined in WAC 388-71-0839 (1) through (12), a natural, step, or adoptive parent who is the individual provider for his or her adult child receiving services through the DSHS division of developmental disabilities must complete the twelve hour parent provider training, as described in WAC 388-71-0895, within one hundred twenty days from the begin date of the authorization to provide department paid, in-home services.