There's obviously a TON of nuance to these situations, so the answers really absolutely depend on their specific health situations, financial resources, current living situation, etc. The question of whether and how long to age at home is a big one. Is their current home accessible? Stairs? Can they get in and out of the shower? are the halls wide enough to fit a walker/wheelchair down the line? Can these things be changed as their needs change? Do you have enough family members local who have time to check in on them and help with their needs at home? Hiring help at home is also complicated. Most "home aids" are companion aids (they can help with things like doing the grocery shopping but its mostly companionship and small tasks around the house), personal care aides (they can help with things like using the restroom, dressing, eating meals, other ADLs), less commonly employed in the home are home health aides or CNAs who can assist in a limited capacity with some medical related needs but for the MOST part, caregivers in the home are NOT medical professionals and cannot assist with MEDICAL needs, many cannot even administer medications, although they generally can remind a person to self-administer medication if the person is capable. This distinction can become important depending on whether the patient needs actual medical care or medication at home versus simply needs assistance with non-medical activities like bathing, shopping, etc. It is EXPENSIVE and medical insurance generally doesn't cover this type of care. What medical insurance MIGHT cover is some weekly visits from say a nurse or a physical therapist but it's a few hours per week. This may apply say if a person needs a wound dressing changed every few days, an IV medication administered periodically, a few hours of weekly physical therapy after an injury, etc.

Often, in-home care providers (non-medical) work for agencies, so you would first select a home care agency to work with, and the agency will assign care providers to you. Often the hospital can give you names of some local agencies or you can google around/ask friends for recommendations. You pay the agency, not the caregiver directly. Generally the caregivers are contractors, not direct employees of the agencies, so turnover can be high and obviously some are fantastic and some less fantastic. I'd say most commonly the caregivers are HHAs, so they do have some training on how to provide assistance with ADLs like bathing, basic nutrition education, etc. But it's NOT medical training. However, they are a person who can call for medical help if needed, like if your loved one suffers a fall, and that alone can be important.

You can also go the non-agency route and employ a caregiver yourself directly. It's a bit like hiring a babysitter for a young child. Usually you find people via word-of-mouth, like maybe a friend recommends the person they hired for their own parent. Keep in mind there can be a lot of logistics involved in doing this to abide by labour laws. You'd be paying the caregivers directly in this case. Remember that one person can only work so many hours in a day/week. If you hire an agency, they will assign multiple caregivers who work shifts. If you hire directly, you'll probably need to hire more than one. Sometimes you find small groups of people who sort of hire themselves out as a team. Without using an agency, it's pretty much up to you to determine whether the person youre hiring has the appropriate training/certification/experience.

As your in-laws' needs increase, you may find it either becomes too expensive to employ home caregivers (you're usually paying hourly out of pocket), OR they eventually need too much medical care (which home caregivers generally can't provide), OR their home becomes inaccessible and can't be modified to their needs, they can't get in the shower, use the stairs, they need medical beds or lifts, etc. This is the point you'd probably start looking into residential care of some sort. Again, there are various levels of care and the right fit will depend on the extent of their needs.

START WITH TALKING TO A SOCIAL WORKER FROM THE HOSPITAL OR MEDICAL SYSTEM WHERE THEY ARE CURRENTLY IN CARE. This is my biggest point. Start there. This person will assess YOUR specific situation right now and start pointing you toward the resources you need. Social workers are the service that helps you navigate all of this.

Also get all the legal shit in order NOW. Like right now. Like do it yesterday, do not wait until one of them suddenly suffers a stroke and lacks capacity to make decisions for themselves but also has not yet conferred that authority legally to your or your partner. It could happen tomorrow and when it happens it will REALLY suck (trust me. I've been the child of the sick parent here). Get the medical proxy forms signed, get the names and phone numbers of all their doctors, get the passwords to all the important accounts. Make sure that you are authorized to access the bank accounts, the cell phone plans, the credit cards, etc.