SELECT	TOP 10 C.ENCOUNTER_KEY, CA.ACTIVITY_KEY
FROM 
(
SELECT	ENCOUNTER_KEY, CLAIM_KEY, 
		ROW_NUMBER() OVER( PARTITION BY ENCOUNTER_KEY ORDER BY ISNULL(CLAIM_CREATION_DT, 0) DESC) Claim_RowNo
FROM	CLAIM WITH(NOLOCK)
) C
INNER JOIN
(
	SELECT	CLAIM_KEY, ACTIVITY_KEY, 
			ROW_NUMBER() OVER( PARTITION BY CLAIM_KEY ORDER BY CLAIM_AMT_KEY DESC ) Claim_Amt_RowNo 
	FROM	CLAIM_AMT WITH(NOLOCK)
) CA
ON C.CLAIM_KEY = CA.CLAIM_KEY AND Claim_RowNo = 1 AND Claim_Amt_RowNo = 1

SELECT	TOP 10 ENCOUNTER_KEY, ACTIVITY_KEY
FROM 
(
SELECT	
		C.ENCOUNTER_KEY, 
		C.CLAIM_KEY,
		CA.ACTIVITY_KEY 
		ROW_NUMBER() OVER( PARTITION BY ENCOUNTER_KEY, CLAIM_Key ORDER BY ISNULL(CLAIM_CREATION_DT, 0) DESC, CLAIM_AMT_KEY DESC) RowNo
FROM	CLAIM C WITH(NOLOCK) 
INNER JOIN CLAIM_AMT CA WITH(NOLOCK)
On C.CLAIM_KEY = CA.CLAIM_KEY 
) A
Where RowNo = 1