(1) From individual case mix weights for the applicable quarter, the department shall determine two average case mix indexes for each medicaid nursing facility, one for all residents in the facility, known as the facility average case mix index, and one for medicaid residents, known as the medicaid average case mix index.

     (2)(a) In calculating a facility's two average case mix indexes for each quarter, the department shall include all residents or medicaid residents, as applicable, who were physically in the facility during the quarter in question based on the resident assessment instrument completed by the facility and the requirements and limitations for the instrument's completion and transmission (January 1st through March 31st, April 1st through June 30th, July 1st through September 30th, or October 1st through December 31st).

     (b) The facility average case mix index shall exclude all default cases as defined in this chapter. However, the medicaid average case mix index shall include all default cases.

     (3) Both the facility average and the medicaid average case mix indexes shall be determined by multiplying the case mix weight of each resident, or each medicaid resident, as applicable, by the number of days, as defined in this section and as applicable, the resident was at each particular case mix classification or group, and then averaging.

     (4) In determining the number of days a resident is classified into a particular case mix group, the department shall determine a start date for calculating case mix grouping periods as specified by rule.

     (5) The cutoff date for the department to use resident assessment data, for the purposes of calculating both the facility average and the medicaid average case mix indexes, and for establishing and updating a facility's direct care component rate, shall be one month and one day after the end of the quarter for which the resident assessment data applies.

     (6)(a) Although the facility average and the medicaid average case mix indexes shall both be calculated quarterly, the cost-rebasing period facility average case mix index will be used throughout the applicable cost-rebasing period in combination with cost report data as specified by RCW 74.46.431 and 74.46.506, to establish a facility's allowable cost per case mix unit. To allow for the transition to minimum data set 3.0 and implementation of resource utilization group IV for July 1, 2011, through June 30, 2013, the department shall calculate rates using the medicaid average case mix scores effective for January 1, 2011, rates adjusted under RCW 74.46.485(1)(a), and the scores shall be increased each six months during the transition period by one-half of one percent. The July 1, 2013, direct care cost per case mix unit shall be calculated by utilizing 2011 direct care costs, patient days, and 2011 facility average case mix indexes based on the minimum data set 3.0 resource utilization group IV grouper 57. A facility's medicaid average case mix index shall be used to update a nursing facility's direct care component rate semiannually.

     (b) The facility average case mix index used to establish each nursing facility's direct care component rate shall be based on an average of calendar quarters of the facility's average case mix indexes from the four calendar quarters occurring during the cost report period used to rebase the direct care component rate allocations as specified in RCW 74.46.431.

     (c) The medicaid average case mix index used to update or recalibrate a nursing facility's direct care component rate semiannually shall be from the calendar six-month period commencing nine months prior to the effective date of the semiannual rate. For example, July 1, 2010, through December 31, 2010, direct care component rates shall utilize case mix averages from the October 1, 2009, through March 31, 2010, calendar quarters, and so forth.

[2011 1st sp.s. c 7 § 6; 2010 1st sp.s. c 34 § 11; 2006 c 258 § 5; 2001 1st sp.s. c 8 § 9; 1998 c 322 § 24.]

NOTES:

     Purpose -- Findings -- Intent -- Severability -- Effective date -- 2011 1st sp.s. c 7: See RCW 74.48.005, 74.48.900, and 74.48.901.

     Analysis -- 2011 1st sp.s. c 7: See note following RCW 74.46.431.

     Effective date -- 2010 1st sp.s. c 34: See note following RCW 74.46.010.

     Effective date -- 2006 c 258: See note following RCW 74.46.020.

     Severability -- Effective dates -- 2001 1st sp.s. c 8: See notes following RCW 74.46.020.