20 CFR § 404.131 - When you must have disability insured status.
(a) For a period of disability. To establish a period of disability, you must have disability insured status in the quarter in which you become disabled or in a later quarter in which you are disabled.
(b) For disability insurance benefits.
(2) If you do not have disability insured status in a month specified in paragraph (b)(1) of this section, you will be insured for disability insurance benefits beginning with the first month after that month in which you do meet the insured status requirement and you also meet all other requirements for disability insurance benefits described in § 404.315.