Goodwill is attributable to the acquisition of our pharma services in July 2019. The carrying value of the intangible assets acquired was $15.6 million, with goodwill of approximately $8.3 million and identifiable intangible assets of approximately $7.3 million. The goodwill balance at June 30, 2022 was $8.4 million. The net carrying value of the identifiable intangible assets from all acquisitions as of June 30, 2022 and December 31, 2021 are as follows:

SCHEDULE OF IDENTIFIABLE INTANGIBLE ASSETS CARRYING VALUE  

Amortization expense was approximately $0.5 million and $1.1 million for the three-month periods ended June 30, 2022 and 2021, and $1.1 million and $2.2 million for the six-month periods ended June 30, 2022 and 2021, respectively. Estimated amortization expense for the remainder of 2022 and the next four years is as follows:

SCHEDULE OF FUTURE ESTIMATED AMORTIZATION EXPENSE 

The following table displays a roll forward of the carrying amount of goodwill from December 31, 2021 to June 30, 2022:

SCHEDULE OF GOODWILL CARRYING VALUE