I have many healthcare issues in my family, so I have a lot of experience with this. It is very dependent on the field. Some are booked out for months, others you can get an appointment the week of, it is very hard to predict. Also, most medical professionals leave some amount of week-space open for emergencies, so if you REALLY need to see someone, you can in less than 24 hours in many cases. But if it's routine or part of a larger "wtf is going on" process, it can take a year to get a diagnosis bouncing between different specialists with 1+ month scheduling runways.

Currently, the industry is also facing a labor shortage, so this is making the scheduling even harder. A family member in high school was diagnosed with obstructive sleep apnea (affecting school performance! You only get 8 semesters to mess up!), and it has been (so far) 8 weeks and we still don't have a formal intake for medical equipment. We have a prescription. We just can't get the equipment supplier to process the prescription and send it to us. I ended up paying out of pocket (and doing some crazy shit) to get a machine and supplies. Note: this is with doing what is basically a part-time job squeaky-wheeling everyone I can to try to get things happening. It is the worst.

Blue collar medical workers are quitting in droves because the work sucks and it has garbage pay, and you see the executives making huge salaries. And you get yelled at by people like me trying to make the system move faster. I try to stay friendly, but... I have lost it a few times. Of the seven people in my family, five of us have chronic medical issues.

I was just talking the other day with a friend wishing there was a medical consultancy I could hire. I give them my health insurance info and family demographics and all of the healthcare shit we need done, and then they find the providers, make appointments, file reimbursements with insurance/hsa/fsa tell me how much to put in fsa/hsa each year, deal with the full time job of having a family that needs to deal with the totally bonkers american medical system. They get some commission of whatever comes back to me, and also just some baseline monthly payment for service. PLEASE GOD LET THIS BECOME A THING. Or, you know, a not insane medical system.

4-6 months has become extremely common now a days. If you only have to wait a month drop to your knees and praise the deity of your choice

If you've ever been on the scheduling side of these things, you'll see that a lot of these waits come down to inefficient scheduling. If you've waited a month for your appointment, there's a good chance there were multiple cancellations before that you didn't hear about.