BDD,
Here's the XJT example ( I guess it's in effect). Not sure how much variation there is from one carrier to another or who else might be offering it. Poor 'ol XJT needs all the help it can get:
“The tentative deal would allow pilots to count
up to 10 years of previous experience at Federal Aviation Regulation Part 121 carriers toward their tenures
for purposes of hourly pay according to the specific equipment and status. That experience would also count toward benefits such as the 401(k) retirement match, defined contributions and vacation accrual.”
https://www.ainonline.com/aviation-n...le-credit-plan