I read some where in this forum that I485 is work related and may not applicable here. I may be wrong.
The I-485 is the U.S. domestic equivalent to getting an Immigrant Visa at a Consulate. In either approach to processing one for an "Immigrant Status in the U.S. (LPR) or "greencard"" they rely on the same
statute, the Immigration and Nationality Act (INA or Act).
DHS (including USCIS, CBP, ICE, ICE Health Service Corps and TSA), DOS, DOJ (including the AG, the Civil Division--OIL and US Attorneys, and EOIR--IJ's and BIA), HHS (including Refugee Office, and CDC), APHIS, and DOL all have
regulations some are exclusive and others are shared.
The underlying basis for immigrating varies widely as to relationships, qualifications, petitioners/sponsors, forms, fees and processing procedures.
There is Family Based immigration with an I-130.
Employment based is via the I-140 for the most part.
Alien investors/entrpreneurs file an I-526.
The I-360 is used for a variety of oddball categories: widow(er)s of a USC, Abused spouse, child or parent, Amerasians, religious workers, juvenile wards of the court,and longterm alien service members (12+ years service) these folks have something that prevents rapid naturalization but does not prove inadmissible as an LPR,...
The I-730 is the petition for follow to join derivatives of an asylee or refugee. [There is a time and status condition on the petitioner for filing then it may switch over to an I-130.]
An asylee or refugee does not need a petition, just have the underlying status for a year to get a greencard.
And DV (diversity visa) winners presents a copy of their notification letter from DOS.
There are further oddball things and new ones come along at the whim or Congress and through litigation in the Courts.
Family based immigrants generally require an I-864 in some form. Widow(er)s of a USC are exempt. Children who automatically acquire USC upon entry/admission are exempt.
Asylees and refugees and wards of the court are exempt.
DV's need either a solid job offer, independent means, or an I-134.
Beneficiaries of I-730's apply for visas abroad. If in the U.S. they either get the asylee status along with the principal or fall into the I-130 route
afterwards when the principal gets a greencard.
An investor or employment-based (including religious workers on the I-360) immigrate because of jobs and UNLESS the employer is a relative, does not need an I-864.
ALL I-485's include in the single fee, the optional forms I-765 and I-131 (renewals are free of charge while the I-485 is pending). The I-131 is NO GOOD for someone with unlawful presence in excess of 180 days.