Hellobee Boards

We are JUST now transitioning to 3 naps at almost 5 months!
I tried to drop the 4th nap too soon. My best advice is to wait until they start REALLY fighting that nap and/or stop acting tired in the late afternoon. I also had to combine dropping the fourth nap with some (additional) nap training...they have been habitual catnappers who sleep 30 minutes or less. I was only able to drop the 4th nap once I trained them to sleep for 1+ hours. But it sounds like you have that part under control! Lucky
Other tips:
-I extended the awake time by 10-15 minutes over the course of several days, with their longest stretches being in the afternoon, (I would usually try to have them go about 2-2.25 hrs right before bedtime). In our case, that means they are done napping by about 4:45. Sometimes it's pretty brutal, so we do a lot of dancing, singing, and shenanigans to keep them semi-happy when they were getting tired.
-Bedtime came early when we first dropped that 4th nap. They used to go down between 7-7:30, but for the last couple of weeks after dropping the nap, it has been more like 6:30-7. That didn't seem to affect their morning wake up time, thankfully!
- There are some days where we just don't make it. On those days, they take a catnap for 20-30 minutes around 5pm. I'll let them doze in the swing, or I'll put them in the stroller and take a walk just so they can hang on until bedtime

I've been wondering this too. dS has been doing the 4 nap thing, and it's been killer for me. I end up wearing him in my wrap for at least one nap a day, and usually that's his best one (can be almost 2 hrs!) his naps in his crib took a nosedive at 4 months, so we are building back up from every nap being 45 mins, to today where we've had a good 90 min and 2 hr nap already. I'm trying to slowly slowly extend his awake time so that we can ditch one nap by the time he's 5.5 months. We will see if it works!