How often can I travel on a pending I-485 and approved I-131?

I would recommend limiting the travel. When you do, do not spend more than six months consecutively outside of the U.S. Try to limit time spent outside of the U.S. to 180 total days in a given year.

There is no specific limit on the number of trips. You should be able to travel within the validity period of the advance parole document and ensure you renew if your pending AOS is still not adjudicated prior to its expiration. It is OK to study abroad as long as you return within the validity period of your advance parole and do not depart the U.S. without a valid advance parole document.

Generally, an I-131 travel document can be used up to two years. However, if you intend to study abroad that could be fine, but be advised that the duration of staying outside the U.S. cannot be the entire two years. Advisably, consult your attorney to make sure that the study abroad is well-planned to avoid an undue overstay outside the U.S.

You can make multiple trips outside of the United States with an approved advance parole document. While your I-485 application is pending, it is not advisable to be outside of the U.S. for extended periods of time.

Surely you have an immigration lawyer helping you with your case. You should discuss these issues with him or her, as the answer can be somewhat complicated. If you stay outside the USA too long after getting your green card, you stand a chance of losing your green card status. If you have an I-485 pending, you can travel outside the USA, but again, if you are gone too long, they could challenge your status and say that you have abandoned your application. You should have been given travel permission when you applied for your I-485 status. It governs how long you can be gone. Discuss all this with your lawyer.

You can travel as frequently as you wish during the validity period of the advance parole. If you wish to study abroad you would need to obtain the proper visa status from the country where you will be studying.

You can travel as much as you deem necessary on your advance parole. You should never stay out of the country on any one trip more than six months. Yes, it is OK to study abroad.

You can travel as frequently as you need to but your primary ties should be to the U.S. Maximum time out of the U.S. is one year.

You can travel abroad almost every day. However, the idea is you are supposed to be living in the U.S. and the travel is incidental to your primary purpose. Moreover, if you are not living here during the I-485 pending period, that indicates you may not be living here after approval, and that may give some officers cause for concern as to whether you have the required immigrant intent. That is, the intent to actually live here.

The advance parole (travel permit or I-130 card) is typically a multiple entry up to the ending date on the card.

Your immigration lawyer should guide you through this. I-131 for multiple entries is good for one year, which is what is issued with pending I-485. It does not limit how many times you could leave and come back. Also, as long as the EAD/travel card is valid, you should be able to study abroad for a semester, for example, and come back.

You may remain outside the United States during the validity of the advance parole travel document.

No, limit to the number of trips. Should be no more than 90 days.