There are a number of concerns in play that must be considered when answering this question, and the answers have recently changed. If you are still a full-time employee in good standing at an approved H1B employer, and have a valid H1B visa stamp, or can apply for a new one on a short trip abroad without a harrowing, uncertain and lengthy procedure, then until the mid-2017 it was vastly preferable to use the H1B visa for travel, as it did not entail going through Secondary Inspection, and did get you readmitted to the United States in H1B nonimmigrant visa status. Now, if you travel abroad on your H1B (or L-1) visa with a Form I-131 Advance Parole application still pending, and re-enter the US on the work visa, USCIS will deem your pending I-131 application abandoned, whether it is a new I-131 based on a recent Adjustment of Status filing, or a renewal. This change occurred suddenly and without warning in the summer of 2017, and indicates a radical re-interpretation of the regulations at 8 CFR 245.2(a)(4)(ii)(C) on the part of USCIS.
If the traveler presents a valid H1B visa, he or she will be re-admitted in valid H1B non-immigrant visa status – This will keep the person in a work-authorized nonimmigrant status and will also preserve the pending I-485 Adjustment of Status application under the regulation cited above, but it will terminate any pending application for Advance Parole. Per that section, visa holders may travel on a valid H1B or L-1 visa as soon as the I-485 receipt notice arrives, instead of having to wait months for the approval of ancillary travel benefits. Travel on an H or L visa will usually avoid having to go to Secondary Inspection upon your return to a US airport. Travel abroad on any other type of nonimmigrant visa will abandon the pending I-485 application and forfeit the fees. However, some H1B workers are subject to extraordinary levels of scrutiny and indeed bias at some airports, particularly information technology professionals working for a consultancy and placed at third-party client sites, so the risks of traveling on the H1B visa, the status of your current employment, and the airport where you plan to return and seek readmission to the US should be discussed with counsel before you go. Clearly, travel on the visa not a good idea if there are any issues with maintenance of H1B status, such as benching, recent change of client site not approved by USCIS, recent or impending termination, etc.
Travel on Advance Parole is possible as soon as the applicant receives the combination EAD card with Advance Parole endorsement from USCIS, or an emergency Advance Parole paper document. Any traveler who presents Advance Parole at a Port of Entry will be admitted as a Parolee rather than in H1B status, and any traveler who presents an Advance Parole travel document to U.S. Customs & Border Protection must always go through Secondary Inspection, where the Customs & Border Protection inspectors start with a presumption that you are inadmissible because of the Advance Parole, and work backwards from there – which means entry coming back to the U.S. will always take longer with an Advance Parole than with the H1B visa, and may be a more adversarial and uncomfortable process.
Once you are admitted as a Parolee:
A. You’re no longer in valid H1B non-immigrant work visa status.
B. In order to stay on payroll once you return to the US in Parolee status, you must present your employer with a valid EAD card and execute a new I-9 Employment Eligibility form, as the basis for authorization to work has changed.
C. You will no longer have access to H1B portability, should you wish to change jobs swiftly, so it is important to file to renew your EAD at least 120 days in advance of expiry if you want to remain flexible.
Additional hurdles to flexibility have arisen for travelers with pending I-485 Adjustment of Status applications who are already dependent on the combined Employment Authorization Document/Advance Parole combo card. There are reports of USCIS denying pending I-131 applications to renew Advance Parole travel authorization where the applicant already has a previous EAD/AP card and uses it for foreign travel after a renewal application is filed. USCIS may also deny the initial I-131 application filed concurrently with the I-485 at a Service Center if the traveler obtains a short-term emergency Advance Parole travel document from a USCIS Field Office and travels with that.Contact