-- METHOD A [GROUP BY]
 SELECT COUNT(*) AS Months_Rptd
 FROM
  (     
    SELECT
      TO_CHAR(TRUNC(claim_end_dt,'MON'), 'MM/YYYY') AS MonthYear,
      COUNT(claim_end_dt)                           AS ClaimCount
    FROM claims_hist_tbl
    WHERE trunc(claim_end_dt) BETWEEN to_date('07012014','MMDDYYYY') 
                              AND to_date('06302015','MMDDYYYY') 
    GROUP BY TRUNC(claim_end_dt,'MON')
    HAVING COUNT(claim_end_dt) > 0
  );

  -- METHOD B [DISTINCT]
  SELECT COUNT(*) FROM
  (
    SELECT DISTINCT(TO_CHAR(TRUNC(claim_end_dt,'MON'), 'MM/YYYY')) AS MonthYear
    FROM claims_hist_tbl
    WHERE trunc(claim_end_dt) BETWEEN to_date('07012014','MMDDYYYY') 
                              AND to_date('06302015','MMDDYYYY') 
  );

  -- METHOD C
  SELECT 
  COUNT(DISTINCT TO_CHAR(TRUNC(claim_end_dt,'MON'), 'MM/YYYY'))
  FROM claims_hist_tbl
  WHERE trunc(claim_end_dt) BETWEEN to_date('07012014','MMDDYYYY') 
                            AND to_date('06302015','MMDDYYYY')