"in the initial years" is a correct and usable phrase in written English.
You can use it to refer to the early stages or periods of something. For example: "In the initial years of the marriage, they were truly happy."
Watching the Bulls in the initial Years Since Jordan was agony.
Especially in the initial years after 9/11, women faced a lot of skepticism on those teams.
"Therefore, one never saw any films that referred to Pakistan, even diagonally, in the initial years of India's formation".
He said he had been subjected to numerous hate crimes, particularly in the initial years when he was still unable to speak English properly.
In the initial years of a new market, the first mover tended to maintain a profit advantage, as the revenue benefit outweighed the cost penalty.
Under the ACA, the federal government paid the entire cost in the initial years for any state that chose to expand Medicaid.
Structured training on box trainers in laparoscopic skills in the initial years of residency has been used and found to be effective.
In the initial years of joining the union Croatian exporters to the rest of former Yugoslavia will have to cope with additional tariffs.
Though continuing to use Latin in instruction, they promoted also the use of the vernacular French in the initial years of their curriculum.
One important aspect of achieving this is improving the transition processes between Medicaid and Marketplace coverage, which has been difficult for applicants in some states in the initial years of the ACA.
Pentagon officials said that several hundred military or Pentagon personnel declined the vaccine in the initial years of the program, but that only 10 had refused vaccination since June 2002, when the program was accelerated after supply problems were resolved.
