404.120—How we determine currently insured status.
        
        (a) What the period is for determining currently insured status.
         You are currently insured if you have at least 6 quarters of coverage (QCs) during the 13-quarter period ending with the quarter in which you—
    
    
    
    
    
        
        (b) What quarters are not counted as part of the 13-quarter period.
         We do not count as part of the 13-quarter period any quarter all or part of which is included in a period of disability established for you, except that the first and last quarters of the period of disability may be counted if they are QCs (see  § 404.146(d) ).