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Section 101(a)(15)(H) of the Immigration and Nationality Act (or "INA") technically also includes Section 101(a)(15)(H)(i)(b1) which refers to H-1B1.
For example, if you have already accumulated 2 years of H-1B1 status in the U.S., you will only be entitled to 4 years (instead of 6 years) of H-1B status.
However, you can be entitled to the full 6 years of H-1B status if (after ending your time in the U.S. working on H-1B1 status) you have resided and been physically present outside the U.S. for 1 year immediately prior to seeking H-1B status, per 8 CFR 214.2(h)(13)(iii)(A) above.
Footnote: For avoidance of doubt, note that unless your employer is a "cap-exempt petitioner" you would be subject to the H-1B lottery if you're seeking H-1B status for the first time, even if you have been on H-1B1 status before.
Question (2): If so, can any time spent outside the U.S. during H-1B1 also be recaptured and added towards my H-1B time?
As you can see from the response to Question (1), your H-1B1 time in the U.S. counts towards your H-1B time, unless you meet the exception of physically residing outside the U.S. for 1 year in between described above.
The understandable follow-up question is: If so, for the purposes of H-1B can I also recapture time spent outside the U.S. back when I was on H-1B1 status?
The answer is: YES.
For example, if you have been working in the U.S. for 4 years on H-1B1 status, but out of that 4 years you've spent a total of 45 full days outside the U.S., you can recapture those 45 days and add them to the amount of remaining H-1B time you will seek.
Practical tip: Typically your I-94 travel history is the most efficient way of checking and proving your time outside of the U.S. because it shows your departure and arrival dates. This can be accessed online here (click on "VIEW TRAVEL HISTORY").
Disclaimer: This blog post is for informational purposes only and does not constitute legal advice.