Section 158.220 - Aggregation of data in calculating an issuer's medical loss ratio(a)Aggregation by State and by market. In general, an issuer's MLR must be calculated separately for the large group market, small group market and individual market within each State. However, if a State requires the small group market and individual market to be merged, then the data reported separately under subpart A of this part for the small group and individual market in that State must be merged for purposes of calculating an issuer's MLR and any rebates owing.(b)Years of data to include in calculating MLR. Subject to paragraphs (c) and (d) of this section, an issuer's MLR for an MLR reporting year is calculated according to the formula in § 158.221 of this subpart and aggregating the data reported under this part for the following 3-year period:(1) The data for the MLR reporting year whose MLR is being calculated; and(2) The data for the two prior MLR reporting years.(c)Requirements for MLR reporting years 2011 and 2012.(1) For the 2011 MLR reporting year, an issuer's MLR is calculated using the data reported under this part for the 2011 MLR reporting year only.(2) For the 2012 MLR reporting year-(i) If an issuer's experience for the 2012 MLR reporting year is fully credible, as defined in § 158.230 of this subpart, an issuer's MLR is calculated using the data reported under this part for the 2012 MLR reporting year.(ii) If an issuer's experience for the 2012 MLR reporting year is partially credible or non-credible, as defined in § 158.230 of this subpart, an issuer's MLR is calculated using the data reported under this part for the 2011 MLR reporting year and the 2012 MLR reporting year.(d)Requirements for MLR reporting years 2013 and 2014 for the student market only.(1) For the 2013 MLR reporting year, an issuer's MLR is calculated using the data reported under this part for the 2013 MLR reporting year only.(2) For the 2014 MLR reporting year- (i) If an issuer's experience for the 2014 MLR reporting year is fully credible, as defined in § 158.230 of this subpart, an issuer's MLR is calculated using the data reported under this part for the 2014 MLR reporting year.(ii) If an issuer's experience for the 2014 MLR reporting year is partially credible or non-credible, as defined in § 158.230 of this subpart, an issuer's MLR is calculated using the data reported under this part for the 2013 MLR reporting year and the 2014 MLR reporting year. 75 FR 74921 , Dec. 1, 2010, as amended at 77 FR 16469 , Mar. 21, 2012; 79 FR 30352 , May 27, 2014