<prompt> tafsiri zifuatazo kutoka kwa swahili hadi kiingereza.ikiwa otomatiki imeruhusiwa chini ya sheria husika, unaweza kuchagua huduma ibadilishe kiotomatiki mwisho wa kipindi kilichowekwa cha huduma.  <response>: if youre already signed up for medicare, you can change plan options during the annual enrollment period. 